Patent Application
20220205050
The present application relates to methods and markers for identifying and quantifying nucleic acid sequence, mutation, copy number, and/or methylation changes using combinations of nuclease, ligation, DNA repair and polymerase reactions with carryover prevention.
Cancer is the leading cause of death in developed countries and the second leading cause of death in developing countries. Cancer kills 580,000 patients annually in the US, 1.3 million in Europe, and 2.8 million in China (Siegel et al., “Cancer Statistics, 2016,” CA Cancer J. Clin. 66(1):7-30 (2016)). Cancer is now the biggest cause of mortality worldwide, with an estimated 8.2 million deaths from cancer in 2012 (Torre et al., “Global Cancer Statistics, 2012,” CA Cancer J. Clin. 65(2):87-108 (2015)). Cancer cases worldwide are forecast to rise by 75% and reach close to 25 million over the next two decades. The lifetime risk of a woman dying from an invasive cancer is 19%, for a man it is 23%. With total annual costs of cancer care in the U.S. exceeding $400 billion, there is no other medical issue that so urgently needs intelligent solutions.
In the U.S., new cancer cases among men are dominated by prostate (21%), lung (14%), colorectal (8%), urinary bladder (7%), melanoma (6%), non-Hodgkin lymphoma (5%), renal (5%), head and neck (4%), leukemia (4%), and liver and bile cancer (3%). Among women, most of the newly diagnosed cancers are breast (29%), lung (13%), colorectal (8%), uterine corpus (7%), thyroid (6%), non-Hodgkin lymphoma (4%), melanoma (3%), leukemia (3%), pancreatic (3%), and renal cancer (3%). The leading causes of cancer deaths are lung cancer (27%), prostate cancer (8%), colorectal cancer (8%), and lung cancer (26%), breast cancer (14%), colorectal cancer (8%), for men and women, respectively. These cancers are driven by different biological processes, and while there have been exciting advancements in the treatment of some cancers, such as the emergence of targeted therapeutics and immunotherapy, most cancers are found at later stage, where survival is poor. Due to lack of reliable and inexpensive early detection tests, many cancer types are diagnosed at later stages, where survival rates for some cancers drop to below 10%. The current screening technologies are failing due to low patient compliance, high expense, and low sensitivity and specificity rates (Das et al., “Predictive and Prognostic Biomarkers in Colorectal Cancer: A Systematic Review of Recent Advances and Challenges,” Biomedicine & Pharmacotherapy 87:8-19 (2016)). For example, the high cost, discomfort, and invasiveness of colonoscopy are significant impediments to patient compliance for CRC screening (Beydoun et al., “Predictors of Colorectal Cancer Screening Behaviors Among Average-risk Older Adults in the United States,” Cancer Causes & Control: CCC 19(4):339-359 (2008)). Likewise, patient distaste for handling feces has limited the success of FOBT/FIT, and eliminated stool-based tests as a remedy for low compliance. In contrast, the current proposal addresses these problems by developing a blood test with the potential to become widely adopted. Increasing patient compliance for CRC testing will lead to earlier detection and, ultimately, increased patient survival.
Ultimately, there is an urgent need to develop non-invasive, highly sensitive, highly specific, and cost-effective tests which will detect early-stage cancers. Two relatively recent developments in cancer research serve as the guiding principles for these tasks. First, is the use of modern genomic tools (such as genome-wide sequencing, transcriptional, and methylation profiling). Public accessibility to vast databases generated from these studies has accelerated the discovery of a wider list of molecular markers (such as promoter methylation, mutation, copy number, or expression levels of mRNA, microRNA, non-coding RNA (ncRNA), and long non-coding RNA (lncRNA) associated with cancer progression. Second is the discovery that nucleic acids can be released by the cancer cells into the patient's bloodstream. Cancer cells may undergo apoptosis (triggered cell death), which releases cell free DNA (cfDNA) into the patients' blood (Salvi et al., “Cell-free DNA as a Diagnostic Marker for Cancer: Current Insights,” OncoTargets and Therapy 9:6549-6559 (2016)). The levels of cfDNA in serum from patients with cancer vary from vanishingly small to high, but do not correlate with cancer stage (Perlin et al., “Serum DNA Levels in Patients With Malignant Disease,” American Journal of Clinical Pathology 58(5):601-602 (1972); Leon et al., “Free DNA in the Serum of Cancer Patients and the Effect of Therapy,” Cancer Res. 37(3):646-650 (1977)). Moreover, exosomes (lipid vesicles ranging from 30 to 100 nm), which are released into the blood by cancer cells, can contain the same RNA molecules which serve as transcriptional signatures of the tumors. Exosomes, or tumor associated vesicles, shield mRNA, lncRNA, ncRNA, and even mutant tumor DNA from exogenous nucleases, and, as such, the markers are in a protected state. Other protected states include, but are not limited to, DNA, RNA, and proteins within circulating tumor cells (CTCs), within other non-cellular membrane containing vesicles or particles, within nucleosomes, or within Argonaute or other protein complexes. cfDNA in particular, contains the same molecular aberrations as the solid tumors, such as mutations hyper/hypo methylation, copy number changes, or chromosomal rearrangements (Ignatiadis et al., “Circulating Tumor Cells and Circulating Tumor DNA for Precision Medicine: Dream or Reality?” Ann. Oncol. 25(12):2304-2313 (2014)).
Tumor-specific CpG methylations have been detected in the plasma from patients with a variety of solid tumors (Pratt V M, “Are We Ready for a Blood-Based Test to Detect Colon Cancer?” Clinical Chemistry 60(9):1141-1142 (2014); Warton et al., “Methylation of Cell-free Circulating DNA in the Diagnosis of Cancer,” Frontiers in Molecular Biosciences 2:13 (2015)), through various techniques involving bisulfite conversion of unmethylated cytosines, methylation-sensitive enzymes, or immunoprecipitation of 5-methylcytosines (Jorda et al., “Methods for DNA methylation analysis and applications in colon cancer,” Mutat. Res. 693(1-2):84-93 (2010)). Methylation signatures have better specificity towards a particular cancer type likely because methylation patterns are highly tissue specific (Issa J P, “DNA Methylation as a Therapeutic Target in Cancer,” Clin. Cancer Res. 13(6):1634-1637 (2007)). The best studied blood-based methylation markers for CRC detection are located in the promoter region of the SEPT9 gene (Church et al., “Prospective Evaluation of Methylated SEPT9 in Plasma for Detection of Asymptomatic Colorectal Cancer,” Gut 63(2):317-325 (2014); Lofton-Day et al., “DNA Methylation Biomarkers for Blood-Based Colorectal Cancer Screening,” Clinical Chemistry 54(2):414-423 (2008); Potter et al., “Validation of a Real-time PCR-based Qualitative Assay for the Detection of Methylated SEPT9 DNA in Human Plasma,” Clinical Chemistry 60(9):1183-1191 (2014); Ravegnini et al., “Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker,” International Journal of Molecular Sciences 16(12):28486-28497 (2015); Toth et al., “Detection of Methylated SEPT9 in Plasma is a Reliable Screening Method for Both Left- and Right-sided Colon Cancers,” PloS One 7(9):e46000 (2002); Toth et al., “Detection of Methylated Septin 9 in Tissue and Plasma of Colorectal Patients with Neoplasia and the Relationship to the Amount of Circulating Cell-Free DNA,” PloS One 9(12):e115415 (2014); Warren et al., “Septin 9 Methylated DNA is a Sensitive and Specific Blood Test for Colorectal Cancer,” BMC Medicine 9:133 (2011)), and other potential markers for CRC diagnostics include CpG sites on promoter regions of THBD (Lange et al., “Genome-scale Discovery of DNA-methylation Biomarkers for Blood-Based Detection of Colorectal Cancer,” PloS One 7(11):e50266 (2012)), C9orf50 (Lange et al., “Genome-scale Discovery of DNA-methylation Biomarkers for Blood-Based Detection of Colorectal Cancer,” PloS One 7(11):e50266 (2012)), ZNF154 (Margolin et al., “Robust Detection of DNA Hypermethylation of ZNF154 as a Pan-Cancer Locus with in Silico Modeling for Blood-Based Diagnostic Development,” The Journal of Molecular Diagnostics 18(2):283-298 (2016)), and AGBL4, Fil1 and TWIST1 (Lin et al., “Clinical Relevance of Plasma DNA Methylation in Colorectal Cancer Patients Identified by Using a Genome-Wide High-Resolution Array,” Ann. Surg. Oncol. 22 Suppl 3:S1419-1427 (2015)). In breast cancer, methylation at promoter regions of tumor suppressor genes (including ATM, BRCA1, RASSF1, APC, and RARI3) has been detected in patients' cfDNAs (Tang et al., “Blood-based DNA Methylation as Biomarker for Breast Cancer: a Systematic Review,” Clinical Epigenetics 8:115 (2016)). A caveat for using methylation markers is that bisulfite conversion tends to destroy DNA, and thus decreases the overall signal that can be detected. Methylation detection techniques may also lead to false-positive signals due to incomplete conversion of unmethylated cytosines. As described herein, an extensive bioinformatics analysis of public databases has been performed to identify CRC-specific, and tissues-specific methylation markers suitable for detection of cancer in the plasma. The methylation marker detection assays enable a higher level of multiplexing with single-molecule detection capabilities, which are predicted to allow for higher sensitivity and specificity across a broad spectrum of cancers.
The challenge to develop reliable diagnostic and screening tests is to distinguish those markers emanating from the tumor that are indicative of disease (e.g., early cancer) vs. presence of the same markers emanating from normal tissue (which would lead to a false-positive signal). There is also a need to balance the number of markers examined and the cost of the test, with the specificity and sensitivity of the assay. Comprehensive molecular profiling (mRNA, methylation, copy number, miRNA, mutations) of thousands of tumors by The Cancer Genome Atlas Consortium (TCGA), has revealed that colorectal tumors are as different from each other as they are from breast, prostrate, or other epithelial cancers (TCGA “Comprehensive Molecular Characterization of Human Colon and Rectal Cancer Nature 487:330-337 (2014)). Further, those few markers they share in common are also present in multiple cancer types, hindering the ability to pinpoint the tissue of origin. BRAF mutations frequently occur in melanoma (42%) and thyroid cancer (41%), while KRAS is also highly mutated in pancreatic (55%) and lung (16%) cancers (Forbes et al., “COSMIC: Exploring the World's Knowledge of Somatic Mutations in Human Cancer,” Nucleic Acids Res. 43(Database issue):D805-811 (2015)). In general, CRC mutation markers such as those of KRAS and BRAF are found in late-stage primary cancers and metastases (Spindler et al., “Circulating free DNA as Biomarker and Source for Mutation Detection in Metastatic Colorectal Cancer,” PloS One 10(4):e0108247 (2015); Gonzalez-Cao et al., “BRAF Mutation Analysis in Circulating Free Tumor DNA of Melanoma Patients Treated with BRAF Inhibitors,” Melanoma Res. 25(6):486-495 (2015); Sakai et al., “Extended RAS and BRAF Mutation Analysis Using Next-Generation Sequencing,” PloS One 10(5):e0121891 (2015)). For early cancer detection, the nucleic acid assay should serve primarily as a screening tool, requiring the availability of secondary diagnostic follow-up (e.g., colonoscopy for colorectal cancer).
Compounding the biological problem is the need to reliably quantify mutation, CpG methylation, or DNA or RNA copy number from either a very small number of initial cells (i.e. from CTCs), or when the cancer signal is from cell-free DNA (cfDNA) in the blood and diluted by an excess of nucleic acid arising from normal cells, or inadvertently released from normal blood cells during sample processing (Mateo et al., “The Promise of Circulating Tumor Cell Analysis in Cancer Management,” Genome Biol. 15:448 (2014); Haque et al., “Challenges in Using ctDNA to Achieve Early Detection of Cancer,” BioRxiv. 237578 (2017)).
Some cancer IVD companies have developed commercially available methylation detection tests. The aforementioned SEPT9 methylation is the basis for Epi proColon test, a CRC-detection assay by Epigenomics (Lofton-Day et al., “DNA Methylation Biomarkers for Blood-based Colorectal Cancer Screening,” Clinical Chemistry 54(2):414-423 (2008)). While initial results on smaller sample sets showed promise, large-scale studies with 1,544 plasma samples showed a sensitivity of 64% for stage I-III CRC, and a specificity of 78%-82%, effectively sending 180 to 220 out of 1,000 individuals to unnecessary colonoscopies (Potter et al., “Validation of a Reg-time PCR-based Qualitative Assay for the Detection of Methylated SEPT9 DNA in Human Plasma,” Clinical Chemistry 60(9):1183-1191 (2014)). Clinical Genomics is currently developing blood based CRC detection test based on the methylation of the BCAT1 and IKZF1 genes (Pedersen et al., “Evaluation of an Assay for Methylated BCAT1 and IKZF1 in Pasma for Detection of Colorectal Neoplasia,” BMC Cancer 15:654 (2015)]. Large-scale studies using 2,105 plasma samples of this two-marker test showed an overall sensitivity of 66%, with 38% for stage I CRC, and an impressive specificity of 94% (Young et al, “A Cross-sectional Study Comparing a Blood Test for Methylated BCAT1 and IKZF1 Tumor-derived DNA with CEA for Detection of Recurrent Colorectal Cancer,” Cancer Medicine 5(10): 2763-2772 (2016)). Exact Sciences and collaborators have slightly improved the sensitivity of CRC fecal tests (Bosch et al., “Analytical Sensitivity and Stability of DNA Methylation Testing in Stool Samples for Colorectal Cancer Detection,” Cell Oncol. (Dordr) 35(4):309-315 (2012); Hong et al., “DNA Methylation Biomarkers of Stool and Blood for Early Detection of Colon Cancer,” Genet. Test. Mol. Biomarkers 17(5):401-406 (2013); Imperiale et al., “Multitarget Stool DNA Testing for Colorectal-Cancer Screening,” N. Engl. J. Med. 370(14):1287-1297 (2014); Xiao et al., “Validation of Methylation-Sensitive High-Resolution Melting (MS-HRM) for the Detection of Stool DNA Methylation in Colorectal Neoplasms,” Clin. Chim. Acta 431:154-163 (2014); Yang et al., “Diagnostic Value of Stool DNA Testing for Multiple Markers of Colorectal Cancer and Advanced Adenoma: a Meta-Analysis,” Can. J. Gastroenterol. 27(8):467-475 (2013)), by adding K-ras mutation as well as BMP3 and NDRG4 methylation markers (Lidgard et al., “Clinical Performance of an Automated Stool DNA Assay for Detection of Colorectal Neoplasia,” Clin. Gastroenterol. Hepatol. 11(10):1313-1318 (2013)). Large-scale studies on 12,500 stool samples claims 93% sensitivity, yet specificity is still only 85%, essentially sending 150 out of 1,000 individuals to unnecessary colonoscopies. Despite logistical issues in handling feces, Exact Sciences recently sold their millionth test. The Cologuard website states the test result has both false-positives and false-negatives, and the test should not be used if the patient has hemorrhoids, menstrual period, or blood in the stool. The Cologuard website also warns that the test is not for use by patients with Ulcerative Colitis (UC), Crohn's disease (CD), Inflammatory Bowel Disease (IBD), or with a family history of cancer. In other words, Exact Sciences excludes the very patients who would most benefit from an accurate CRC detection test. More recently, Laboratory for Advanced Medicine (based in Irvine, Calif. with ties to various Chinese academic institutions) demonstrated the potential of interrogating the methylation status of a single CpG site (cg10673833) for blood-based detection of colorectal cancer (Luo et al., “Circulating Tumor DNA Methylation Profiles Enable Early Diagnosis, Prognosis Prediction, and Screening for Colorectal Cancer,” Science Translational Medicine 12:(524) (2020)).
The majority of current molecular diagnostics efforts in cancer have centered on: (i) prognostic and predictive genomics, e.g., identifying inherited mutations in cancer predisposition genes, such as BrCA1, BrCA2, (Ford et al., Am. J. Hum. Genet. 62:676-689 (1998)) (ii) individualized treatment, e.g., mutations in the EGFR gene guiding personalized medicine (Sequist and Lynch, Ann. Rev. Med, 59:429-442 (2008)), and (iii) recurrence monitoring, e.g., detecting emerging KRAS mutations in patients developing resistance to drug treatments (Hiley et al., Genome Biol. 15: 453 (2014); Amado et al., J. Clin. Oncol. 26:1626-1634 (2008)). Yet, this misses major opportunities in the cancer molecular diagnostics continuum: (i) more frequent screening of those with a family history, (ii) screening for detection of early disease, and (iii) monitoring treatment efficacy. To address these three unmet needs, a new metric for blood-based detection termed “cancer marker load”, analogous to viral load is herein proposed.
DNA sequencing provides the ultimate ability to distinguish all nucleic acid changes associated with disease. However, the process still requires multiple up-front sample and template preparation, and consequently, DNA sequencing is not always cost-effective. DNA microarrays can provide substantial information about multiple sequence variants, such as SNPs or different RNA expression levels, and are less costly then sequencing; however, they are less suited for obtaining highly quantitative results, nor for detecting low abundance mutations. On the other end of the spectrum is the TaqMan™ reaction, which provides real-time quantification of a known gene, but is less suitable for distinguishing multiple sequence variants or low abundance mutations.
NGS requires substantial up-front sample preparation to polish ends and append linkers, and the current error rates of 0.7% are too high to identify 2-3 molecules of mutant sequence in a 10,000-fold excess of wild-type molecules. “Deep sequencing” protocols have been developed to overcome this deficiency by appending unique molecular identifiers to both strands of an individual fragment. These approaches are known as: Tam-Seq & CAPP-Seq (Roche), Circle-Seq (Guardant Health), Safe-SeqS (Personal Genome Diagnostics), ThruPlex (Rubicon Genomics), NEBNext (New England Biolabs), QlAseq (Qiagen), Oncomine (ThermoFisher), Duplex Barcoding (Schmitt), SMRT (Pacific Biosciences), SiMSen-Seq (Stahlberg), and smMIP (Shendure). However, these methods require a 30 to 100-fold depth per mutant strand to verify each mutation and distinguish from other types of sequencing errors. Recent work from MSKCC demonstrates that 60,000-fold coverage is required to accurately identify mutations in plasma from metastatic cancer patients (91% sensitivity, 508-gene panel, 60,000×). Compounding the challenge, a recent paper from NEB has called into question the quality of the most widely used databases for rare variant and somatic mutations (Chen et al., “DNA Damage is a Pervasive Cause of Sequencing Errors, Directly Confounding Variant Identification,” Science 355(6326):752-756 (2017)).
It is critical to match each unmet diagnostic need with the appropriate diagnostic test—one that combines the divergent goals of achieving both high sensitivity (i.e., low false-negatives) and high specificity (i.e., low false-positives) at a low cost. For example, direct sequencing of EGFR exons from a tumor biopsy to determine treatment for non-small cell lung cancer (NSCLC) is significantly more accurate and cost effective than designing TaqMan™ probes for the over 180 known mutations whose drug response is already catalogued (Jia et al., Genome Res. 23:1434-1445 (2013)). The most sensitive technique for detecting point mutations, such as “BEAMing” (Dressman et al., Proc. Natl. Acad. Sci. USA 100: 8817-8822 (2003)), rely on prior knowledge of which mutations to look for, and thus are best suited for monitoring for disease recurrence, rather than for early detection. Likewise, to monitor blood levels of Bcr-Abl translocations when treating CML patients with Gleevec (Jabbour et al., Cancer 112: 2112-2118 (2008)), a simple quantitative reverse-transcription PCR assay is far preferable to sequencing the entire genomic DNA in 1 ml of blood (9 million cells×3 GB=27 million Gb of raw data).
Sequencing 2.1 Gb each of cell-free DNA (cfDNA) isolated from NSCLC patients was used to provide 10,000-fold coverage on 125 kb of targeted DNA (Kandoth et al., Nature 502: 333-339 (2013)). This approach correctly identified mutations present in matched tumors, although only 50% of stage 1 tumors were covered. The approach has promise for NSCLC, where samples average 5 to 20 mutations/Mb, however targeted NGS would not be cost effective for other cancers such as breast and ovarian, that average less than 1 to 2 mutations per Mb. Current up-front ligation, amplification, and/or capture steps required for highly accurate targeted deep sequencing are still more complex than multiplexed PCR-TaqMan™ or PCR-LDR assays.
Deep sequencing of cfDNAs for 58 cancer-related genes at 30,000-fold coverage is capable of detecting Stage 1 or 2 cancer at moderately high sensitivity but missed 29% of CRC, 41% of breast, 41% of lung, and 32% of ovarian cancer, respectively (Phallen et al., “Direct Detection of Early-stage Cancers Using Circulating Tumor DNA,” Science Translational Medicine 9(403) (2017)). An alternative strategy relied on targeted sequencing of an average of 30 bases in 61 segments to interrogate “hot-spot” mutations in 16 genes including TP53, KRAS, APC, PIK3CA, PTEN, missed more early cancers (Cohen et al., “Detection and Localization of Surgically Resectable Cancers with a Multi-analyte Blood Test,” Science (2018). To extend the sensitivity of mutation sequencing, the Hopkins team very recently combined NGS with quantitation of serum protein markers (such as CA-125, CA19-9, CEA, HGF, Myeloperoxidase, OPN, Prolactin, TIMP-1) and improved detection of five cancer types (ovary, liver, stomach, pancreas, and esophagus) at sensitivities ranging from 69% to 98% (Cohen et al. “Detection and Localization of Surgically Resectable Cancers with a Multi-analyte Blood Test,” Science (2018). One caveat of using these protein markers is that prior large-scale studies with age-matched controls (n=22,000) have not shown clinical utility (Jacobs et al., “Prevalence Screening for Ovarian Cancer in Postmenopausal Women by CA 125 Measurement and Ultrasonography,” BMJ 306(6884):1030-1034 (1993)). Thus, in a 2018 JAMA report, “The USPSTF recommends against [CA-125] screening for ovarian cancer in asymptomatic women. This recommendation applies to asymptomatic women who are not known to have a high risk hereditary cancer syndrome” (USPSTF et al., “Screening for Ovarian Cancer: US Preventive Services Task Force Recommendation Statement” JAMA 319(6):588-594 (2018)). Another caveat of using these protein markers is that they reflect tissue damage and are likely to also appear in patients with inflammatory diseases such as arthritis (Kaiser, “Liquid Biopsy for Cancer Promises Early Detection,” Science 359(6373):259 (2018)). With the growing obesity epidemic and an aging population in the U.S., the risk of false-positives from protein markers increases with obesity and age-driven inflammation.
More recently, the NGS sequencing companies (Grail, Guardant Health, Natera, Freenome) have moved aggressively to expand their targeted sequencing panels to also now include whole genome sequencing (WGS) and whole genome bisulfite sequencing (Bis-WGS). The recent results from Grail, abstract published at ASCO 2018 (Klein et al., “Development of a Comprehensive Cell-free DNA (cfDNA) Assay for Early Detection of Multiple Tumor Types: The Circulating Cell-free Genome Atlas (CCGA) Study,” ASCO Annual Meeting 2018, Chicago, Ill.; Abstract 12021 #134)) reveal that while sensitivity claims of detecting “early” CRC are at 63%, that is based on only 27 samples, most of which are Stage III. Even mutation rich lung cancer gives sensitivity at 50%, again with most samples at Stage III. When most of the samples are Stage I & II, such as prostate cancer, the sensitivity for “early cancer” detection drops to <5%. When attempting to detect the most common form of breast cancer (HR+/HER2), the sensitivity drops to <13%. Worse, those breast cancers diagnosed by screening gave sensitivities of <11%. In short, the NGS approach fails by consistently missing 30% to 80% of early-stage cancers (i.e. stage I & II). In a research initially reported in 2019 ASCO meeting (Liu et al., “Simultaneous Multi-cancer Detection and Tissue of Origin (TOO) Localization Using Targeted Bisulfite Sequencing Plasma Cell-free DNA (cfDNA),” ASCO Breakthrough Presentation 2019)), and subsequently published in 2020 (Liu et al., “Sensitive and Specific Multi-cancer Detection and Localization Using Methylation Signatures in Cell-free DNA,” Annals of Oncology; In Press (2020)), GRAIL indicated that their Multi-Cancer Early Detection Test exhibited an Overall Detection Rate (12 deadly cancer types) of 76% (99.3% specificity). A combined analysis of this group of cancers showed robust detection across all stages with detection rates of 39 percent (27-52%), 69 percent (56-80%), 83 percent (75-90%), and 92 percent (86-96%) at stages I (n=62), II (n=62), III (n=102), and IV (n=130), respectively. In another conference, GRAIL and collaborators (Oxnard et al., “Simultaneous Multi-cancer Detection and Tissue of Origin (TOO) Localization Using Targeted Bisulfite Sequencing of Plasma Cell-free DNA (cfDNA),” ESMO Congress (2019)), reported the results from their analysis of cell-free DNA (DNA that had once been confined to cells but had entered the bloodstream upon the cells' death) in 3,583 blood samples, including 1,530 from patients diagnosed with cancer and 2,053 from people without cancer. The patient samples comprised more than 20 types of cancer, including hormone receptor-negative breast, colorectal, esophageal, gallbladder, gastric, head and neck, lung, lymphoid leukemia, multiple myeloma, ovarian, and pancreatic cancer. The overall specificity was 99.4%, meaning only 0.6% of the results incorrectly indicated that cancer was present. The sensitivity of the assay for detecting a pre-specified high mortality cancer (the percent of blood samples from these patients that tested positive for cancer) was 76%. Within this group, the sensitivity was 32% for patients with stage I cancer; 76% for those with stage II; 85% for stage III; and 93% for stage IV. Sensitivity across all cancer types was 55%, with similar increases in detection by stage. For the 97% of samples that returned a tissue of origin result, the test correctly identified the organ or tissue of origin in 89% of cases. However, another 2019 study (reported by GRAIL and collaborators) questioned the validity of the aforementioned reports (Razavi et al., “High-intensity Sequencing Reveals the Sources of Plasma Circulating Cell-free DNA Variants,” Nat Med 25(12):1928-1937 (2019)). Through a 2 Mb, 508-gene panel sequencing (60,000×depth), the authors demonstrated the vast majority of cell-free DNA mutations in both non-cancer controls and cancer patients had features consistent with clonal hematopoiesis, a process whereby white blood cells progressively accumulate somatic alterations without necessarily producing a hematological condition or malignancy. Indeed. mutations appeared in 93.6 percent of the white blood cells from individuals without cancer and 99.1 percent of those with cancer. In a recently held conference, GRAIL and their collaborators reported that their blood-based test can detect multiple GI cancers at sensitivity of under 50% for Stage I, and 73% for Stage 1-III (Wolpin et al., “Performance of a Blood-based Test for the Detection of Multiple Cancer Types,” In: Gastrointestinal Cancers Symposium 2020 (2020)). As for Freenome, a recent ASCO presentation indicated that their platform (plasma analysis by whole-genome sequencing, bisulfite sequencing, and protein quantification methods) was able to achieve a mean sensitivity of 92% in early-stage (n=17) and 84% in late-stage (n=11) at a specificity of 90% for colorectal adenocarcinoma detection. Across all CRC pathological subtypes, the Freenome test achieved a specificity of 90%, and sensitivities of 80% and 83% for early-stage (n=19) and late-stage (n=12), respectively. Private discussion with Imran Haque, who just resigned as CSO of Freenome—where he had a $70 million budget and 30 scientists to sequence the plasma of 817 CRC and matched control patients—confirmed that Freenome (as well as GRAIL) were overcalling the data, and that none of them had a cogent approach to achieve cost-effective true early cancer detection (Wan et al., “Machine Learning Enables Detection of Early-stage Colorectal Cancer by Whole-genome Sequencing of Plasma Cell-free DNA,” BioRxiv 478065 (2018)).
A comprehensive data analysis of over 600 colorectal cancer samples that takes into account tumor heterogeneity, tumor clusters, and biological/technical false-positives ranging from 3% to 10% per individual marker showed that the optimal early detection screen for colorectal cancer would require at least 5 to 6 positive markers out of 24 markers tested (Bacolod et al, Cancer Res. 69:723-727 (2009); Tsafrir et al., Cancer Res. 66: 2129-2137 (2006); Weinstein et al., Nat. Genet. 45: 1113-1120 (2013); Navin N. E. Genome Biol. 15: 452 (2014); Hiley et al., Genome Biol 15:453 (2014)); Esserman et al. Lancet Oncol 15:e234-242 (2014)). Further, marker distribution is biased into different tumor clades, e.g., some tumors are heavily methylated, while others are barely methylated, and indistinguishable from age-related methylation of adjacent tissue. Consequently, a multidimensional approach using combinations of 3-5 sets of mutation, methylation, miRNA, ncRNA, lncRNA, mRNA, copy-variation, alternative splicing, or translocation markers is needed to obtain sufficient coverage of all different tumor clades. Analogous to non-invasive prenatal screening for trisomy, based on sequencing or performing ligation detection on random fragments of cfDNA (Benn et al., Ultrasound Obstet. Gynecol. 42(1):15-33 (2013); Chiu et al., Proc. Natl. Acad. Sci. USA 105: 20458-20463 (2008); Juneau et al., Fetal Diagn. Ther. 36(4) (2014)), the actual markers scored in a cancer screen are secondary to accurate quantification of those positive markers in the plasma.
As pointed out above, cancer-specific RNA markers (including microRNAs, lncRNAs, and mRNAs) may also be present in blood, either free of any compartment (Souza et al., “Circulating mRNAs and miRNAs as Candidate Markers for the Diagnosis and Prognosis of Prostate Cancer,” PloS One 12(9):e0184094 (2017)), or contained in exosomes (Nedaeinia et al., “Circulating Exosomes and Exosomal microRNAs as Biomarkers in Gastrointestinal Cancer,” Cancer Gene Ther 24(2):48-56 (2017); Lai et al., “A microRNA Signature in Circulating Exosomes is Superior to Exosomal Glypican-1 Levels for Diagnosing Pancreatic Cancer,” Cancer Lett 39:86-93 (2017)) or circulating tumor cells (“CTCs”), and have been tagged as potential indicators of early-stage cancers. Challenges abound regarding the use of plasma-derived nucleic markers in early cancer detection, including the minuscule amount of these markers in blood relative to those derived from surrounding cells. Indeed, these limitations make it appear that these “early” detection assays are more likely to detect late-stage primary and metastatic cancers (Pantel “Blood-Based Analysis of Circulating Cell-Free DNA and Tumor Cells for Early Cancer Detection,” PLoS Med 13(12):e1002205 (2016)).
Diagnostic tests that aim to find very rare or low-abundance mutant sequences face potential false-positive signal arising from: (i) polymerase error in replicating wild-type target, (ii) DNA sequencing error, (iii) mis-ligation on wild-type target, (iii) target independent PCR product, and (iv) carryover contamination of PCR products arising from a previous positive sample. The profound clinical implications of a positive test result when screening for cancer demand that such a test use all means possible to virtually eliminate false-positives.
Central to the concept of nucleic acid detection is the selective amplification or purification of the desired cancer-specific markers away from the same or closely similar markers from normal cells. These approaches include: (i) multiple primer binding regions for orthogonal amplification and detection, (ii) affinity selection of CTC's or exosomes, and (iii) spatial dilution of the sample.
The success of PCR-LDR, which uses 4 primer-binding regions to assure sensitivity and specificity, has previously been demonstrated. Desired regions are amplified using pairs or even tandem pairs of PCR primers, followed by orthogonal nested LDR primer pairs for detection. One advantage of using PCR-LDR is the ability to perform proportional PCR amplification of multiple fragments to enrich for low copy targets, and then use quantitative LDR to directly identify cancer-specific mutations. Biofire/bioMerieux has developed a similar technology termed “film array”; wherein initial multiplexed PCR reaction products are redistributed into individual wells, and then nested real-time PCR performed with SYBR Green Dye detection.
Affinity purification of CTC's using antibody or aptamer capture has been demonstrated (Adams et al., J. Am. Chem. Soc. 130: 8633-8641 (2008); Dharmasiri et al., Electrophoresis 30:3289-3300 (2009); Soper et al. Biosens. Bioelectron. 21:1932-1942 (2006)). Peptide affinity capture of exosomes has been reported in the literature. Enrichment of these tumor-specific fractions from the blood enables copy number quantification, as well as simplifying screening and verification assays.
The last approach, spatial dilution of the sample, is employed in digital PCR as well as its close cousin known as BEAMing (Vogelstein and Kinzler, Proc. Natl. Acad. Sci. USA. 96(16):9236-41 (1999); Dressman et al., Proc. Natl. Acad. Sci. USA 100:8817-8822 (2003)). The rational for digital PCR is to overcome the limit of enzymatic discrimination when the sample comprises very few target molecules containing a known mutation in a 1,000 to 10,000-fold excess of wild-type DNA. By diluting input DNA into 20,000 or more droplets or beads to distribute less than one molecule of target per droplet, the DNA may be amplified via PCR, and then detected via probe hybridization or TaqMan™ reaction, giving in essence a 0/1 digital score. The approach is currently the most sensitive for finding point mutations in plasma, but it does require prior knowledge of the mutations being scored, as well as a separate digital dilution for each mutation, which would deplete the entire sample to score just a few mutations (Alcaide et al., “A Novel Multiplex Droplet Digital PCR Assay to Identify and Quantify KRAS Mutations in Clinical Specimens,” J. Mol. Diagn. 21:28-33 (2019); Guibert et al., “Liquid Biopsy of Fine-Needle Aspiration Supernatant for Lung Cancer Genotyping,” Lung Cancer 1768:193-207 (2018); Yoshida et al., “Highly Sensitive Detection of ALK Resistance Mutations in Plasma Using Droplet Digital PCR,” BMC Cancer 18:1136 (2018)).
When developing multiplexed assays, there is a tricky balance between performing enough preliminary cycles of PCR or other amplification techniques to generate sufficient copies of each mutant or methylated region such that when diluting into uniplex qPCR, multiplex qPCR, uniplex droplet PCR or multiplexed droplet PCR there are sufficient copies to get a signal if true positive; and performing too many PCR cycles such that some markers over-amplify while others are suppressed, or relative quantification is lost.
The present application is directed at overcoming these and other deficiencies in the art.
A first aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences of other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences of other parent nucleic acid molecules by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are then provided. One or more primary oligonucleotide primer sets are also provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the target nucleotide sequence and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises of a 5′ primer-specific portion. The sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles. The one or more polymerase extension reaction cycles comprise a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising nucleotide sequences complementary to the target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixtures, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The method further comprises subjecting the one or more first polymerase chain reaction mixtures to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase chain reaction mixtures and for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the target nucleotide sequence or a complement thereof. One or more oligonucleotide probe sets are then provided. Each probe set comprises (a) a first oligonucleotide probe having a 5′ primer-specific portion and a 3′ target sequence-specific portion, and (b) a second oligonucleotide probe having a 5′ target sequence-specific portion and a 3′ primer-specific portion, wherein the first and second oligonucleotide probes of a probe set are configured to hybridize, in a base specific manner, on a complementary target nucleotide sequence of a first polymerase chain reaction product. The first polymerase chain reaction products are blended with a ligase, and the one or more oligonucleotide probe sets to form one or more ligation reaction mixtures. The one or more ligation reaction mixtures are subjected to one or more ligation reaction cycles whereby the first and second oligonucleotide probes of the one or more oligonucleotide probe sets are ligated together, when hybridized to their complementary sequence, to form ligated product sequences in the ligation reaction mixtures wherein each ligated product sequence comprises the 5′ primer-specific portion, the target-specific portions, and the 3′ primer-specific portion. The method further includes providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the ligated product sequence and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the ligated product sequence. The ligated product sequences, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further comprises detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences of other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences of other parent nucleic acid molecules by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules and one or more nucleases capable of digesting nucleic acid molecules present not comprising polymerase-incorporated modified nucleotides are provided. The method also involves providing one or more primary oligonucleotide primer sets. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the target nucleotide sequence and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The sample, the one or more first primary oligonucleotide primers, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix that comprises one or more modified nucleotides that protect extension products but not other DNA from nuclease digestion, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising modified nucleotide bases and comprising the complement of the target nucleotide sequence. The method comprises blending the one or more polymerase extension reaction mixtures comprising the primary extension products with the one or more nucleases. The one or more polymerase extension reaction mixtures comprising the primary extension products with the one or more nucleases are subjected to conditions suitable for digesting nucleic acid molecules but not primary extension products comprising modified nucleotides to produce one or more partially digested polymerase extension reaction mixtures. The method further comprises blending the one or more partially digested polymerase extension reaction mixtures, the one or more secondary primary oligonucleotide primers of the primer sets, a deoxynucleotide mix, and a DNA polymerase to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out two or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the target nucleotide sequence or a complement thereof. One or more secondary oligonucleotide primer sets are then provided. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 3′ portion that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first secondary oligonucleotide primer. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU) containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out two or more second polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further comprises detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues and subjecting the nucleic acid molecules in the sample to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are then provided. The method further involves providing one or more primary oligonucleotide primer sets. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The treated sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the primer sets, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. The method further involves providing one or more oligonucleotide probe sets. Each probe set comprises (a) a first oligonucleotide probe having a 5′ primer-specific portion and a 3′ DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and (b) a second oligonucleotide probe having a 5′ DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion and a 3′ primer-specific portion, and wherein the first and second oligonucleotide probes of a probe set are configured to hybridize, in a base specific manner, on a complementary nucleotide sequence of a first polymerase chain reaction product. The first polymerase chain reaction products are blended with a ligase and the one or more oligonucleotide probe sets to form one or more ligation reaction mixtures. The one or more ligation reaction mixtures are subjected to one or more ligation reaction cycles whereby the first and second oligonucleotide probes of the one or more oligonucleotide probe sets are ligated together, when hybridized to their complementary sequence, to form ligated product sequences in the ligation reaction mixture wherein each ligated product sequence comprises the 5′ primer-specific portion, DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and the 3′ primer-specific portion. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the ligated product sequence and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the ligated product sequence. The ligated product sequences, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures, and the one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are provided, and one or more first primary oligonucleotide primer(s) that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more methylated or hydroxymethylated residue are also provided. The treated sample, the one or more first primary oligonucleotide primers, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that is complementary to a portion of the polymerase extension product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first secondary oligonucleotide primer. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the first polymerase chain reaction mixtures, and conditions suitable for carrying out two or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising a 5′ primer-specific portion of the first secondary oligonucleotide primer, a DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and a complement of the 5′ primer-specific portion of the second secondary oligonucleotide primer. The method further involves providing one or more tertiary oligonucleotide primer sets. Each tertiary oligonucleotide primer set comprises (a) a first tertiary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the first polymerase chain reaction products and (b) a second tertiary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the first polymerase chain reactions product sequence. The first polymerase chain reaction products, the one or more tertiary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU) containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules present in the sample are provided, and one or more primary oligonucleotide primer sets are provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The treated sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the extension reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 3′ portion that is complementary to a portion of a first polymerase chain reaction product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of a first polymerase chain reaction product formed from the first secondary oligonucleotide primer. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out two or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reactions products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules present in the sample are provided. One or more primary oligonucleotide primer sets are also provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer. The treated sample, the one or more first primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The method further comprises subjecting the one or more first polymerase chain reaction mixtures to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reactions products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. One or more secondary oligonucleotide primer sets are provided. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the first polymerase chain reaction products or their complements and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the first polymerase chain reaction products or their complements. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of cells or tissue based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 6-12 markers, 12-24 markers, 24-36 markers, 36-48 markers, 48-72 markers, 72-96 markers, or >96 markers. Each marker in a given set is selected by having any one or more of the following criteria: present, or above a cutoff level, in >50% of biological samples of the disease cells or tissue from individuals diagnosed with the disease state; absent, or below a cutoff level, in >95% of biological samples of the normal cells or tissue from individuals without the disease state; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with the disease state; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without the disease state; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with the disease state. At least 50% of the markers in a set each comprise one or more methylated or hydroxymethylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated or hydroxymethylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with the disease state. The biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells is obtained. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. Nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with the disease state if a minimum of 2 or 3 markers are present or above a cutoff level in a marker set comprising from 6-12 markers; or a minimum of 3, 4, or 5 markers are present or above a cutoff level in a marker set comprising from 12-24 markers; or a minimum of 3, 4, 5, or 6 markers are present or above a cutoff level in a marker set comprising from 24-36 markers; or a minimum of 4, 5, 6, 7, or 8 markers are present or above a cutoff level in a marker set comprising from 36-48 markers; or a minimum of 6, 7, 8, 9, 10, 11, or 12 markers are present or above a cutoff level in a marker set comprising from 48-72 markers, or a minimum of 7, 8, 9, 10, 11, 12 or 13 markers are present or above a cutoff level in a marker set comprising from 72-96 markers, or a minimum of 8, 9, 10, 11, 12, 13 or “n”/12 markers are present or above a cutoff level in a marker set comprising 96 to “n” markers, when “n”>168 markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a solid tissue cancer including colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma, breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma, lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma, prostate adenocarcinoma, invasive urothelial bladder cancer, liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 48-72 total cancer markers, 72-96 total cancer markers or ≥96 total cancer markers. On average greater than one quarter such markers in a given set cover each of the aforementioned major cancers being tested. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >50% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer, said method comprising. The method involves obtaining a biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carring out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 48-72 total cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 72-96 total cancer markers; or a minimum of 6 or “n”/18 markers are present or are above a cutoff level in a marker set comprising 96 to “n” total cancer markers, when “n”>96 total cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of and identifying the most likely specific tissue(s) of origin of a solid tissue cancer in the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprises from 36-48 group-specific cancer markers, 48-64 group-specific cancer markers or 64 group-specific cancer markers, wherein on average greater than one third such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >50% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 36-48 group-specific cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 48-64 group-specific cancer markers; or a minimum of 6 or “n”/12 markers are present or are above a cutoff level in a marker set comprising 64 to “n” group-specific cancer markers, when “n”>64 group-specific cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a gastrointestinal cancer including colorectal adenocarcinoma, stomach adenocarcinoma, or esophageal carcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 6-12 markers, 12-18 markers, 18-24 markers, 24-36 markers, 36-48 markers or ≥48 markers. Each marker is selected by having any one or more of the following criteria for gastrointestinal cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with gastrointestinal cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without gastrointestinal cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with gastrointestinal cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without gastrointestinal cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with gastrointestinal cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with gastrointestinal cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with gastrointestinal cancer if a minimum of 2, 3 or 4 markers are present or are above a cutoff level in a marker set comprising from 6-12 markers; or a minimum of 2, 3, 4, or 5 markers are present or are above a cutoff level in a marker set comprising from 12-18 markers; or a minimum of 3, 4, 5, or 6 markers are present or are above a cutoff level in a marker set comprising from 18-24 markers; or a minimum of 3, 4, 5, 6, 7, or 8 markers are present or are above a cutoff level in a marker set comprising from 24-36 markers; or a minimum of 4, 5, 6, 7, 8, 9, or 10 markers are present or are above a cutoff level in a marker set comprising from 36-48 markers; or a minimum of 5, 6, 7, 8, 9, 10, 11, 12, or “n”/12 markers are present or are above a cutoff level in a marker set comprising 48 to “n” markers, when “n”>48 markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a solid tissue cancer including colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma, breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma, lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma, prostate adenocarcinoma, invasive urothelial bladder cancer, liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 36-48 total cancer markers, 48-64 total cancer markers, or ≥64 total cancer markers, wherein on average greater than half of such markers in a given set cover each of the aforementioned major cancers being tested. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 36-48 total cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 48-64 total cancer markers; or a minimum of 6 or “n”/12 markers are present or are above a cutoff level in a marker set comprising 64 to “n” total cancer markers, when “n”>64 total cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of and identifying the most likely specific tissue(s) of origin of a solid tissue cancer in the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or ≥48 group-specific cancer markers. On average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 24-36 group-specific cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 36-48 group-specific cancer markers; or a minimum of 6 or “n”/8 markers are present or are above a cutoff level in a marker set comprising 48 to “n” group-specific cancer markers, when “n”>48 group-specific cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state to guide and monitor treatment of a solid tissue cancer in one or more of the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or 48 group-specific cancer markers, wherein on average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals with a given tissue-specific cancer will on average have from approximately one-quarter to about one-half or more of the markers scored as present, or are above a cutoff level in the tested marker set, wherein to guide and monitor subsequent treatment, a portion or all of the identified markers scored as present or the identified markers scored as above a cutoff level in the tested marker set are deemed the “patient-specific marker set”, and retested on a subsequent biological sample from the individual during the treatment protocol, to monitor for loss of marker signal, wherein if a minimum of 3 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 12-24 markers; or if a minimum of 4 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 24-36 markers; or a minimum of 5 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 36-48 markers; or a minimum of 6 or “n”/8 markers remain present or remain above a cutoff level in a patient-specific marker set comprising ≥48 to “n” markers, when “n”>48 markers after the treatment protocol has been administered, then the continuing presence of said markers may guide a decision to change the cancer treatment therapy.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state to monitor for recurrence of a solid tissue cancer in one or more of the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual, wherein the plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or 48 group-specific cancer markers, wherein on average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells, wherein the biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals with a given tissue-specific cancer will on average have from one-quarter to about one-half or more of the markers scored as present, or are above a cutoff level in the tested marker set, wherein to monitor for recurrence, a portion or all of the markers scored as being present, or the markers scored as above a cutoff level in the tested marker set are deemed the “patient-specific marker set”, and retested on subsequent biological samples from the individual after a successful treatment, to monitor for gain of marker signal, wherein if a minimum of 3 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 12-24 markers; or if a minimum of 4 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 24-36 markers; or a minimum of 5 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 36-48 markers; or a minimum of 6 or “n”/8 markers reappear or rise above a cutoff level in a patient-specific marker set comprising 48 to “n” markers, when “n”>48 markers after the treatment protocol has been administered, then the reappearance or rise or rise above a cutoff level in a patient-specific marker set may guide a decision to resume the cancer treatment therapy or change to a new cancer treatment therapy.
Another aspect of the present application is directed to a two-step method of diagnosing or prognosing a disease state of cells or tissue based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The method involves obtaining a biological sample, the biological sample including exosomes, tumor-associated vesicles, markers within other protected states, cell-free DNA, RNA, and/or protein originating from the potentially disease state cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. A first step is applied to the biological samples with an overall sensitivity of >80% and an overall specificity of >90% or an overall Z-score of >1.28 to identify individuals more likely to be diagnosed or prognosed with the disease state. A second step is then applied to biological samples from those individuals identified in the first step with an overall specificity of >95% or an overall Z-score of >1.65 to diagnose or prognose individuals with the disease state, wherein said applying the first step and/or said applying the second step is carried out using the methods described above.
The present application describes a number of approaches for detecting mutations, expression, splice variant, translocation, copy number, and/or methylation changes in target nucleic acid molecules using nuclease, ligase, and polymerase reactions. The present application solves the problems of carry over prevention, as well as allowing for spatial multiplexing to provide relative quantification, similar to digital PCR. Such technology may be utilized for non-invasive early detection of cancer, non-invasive prognosis of cancer, and monitoring for cancer recurrence from plasma or serum samples.
The present application provides a comprehensive roadmap of nucleic acid methylation, miRNA, lncRNA, ncRNA, mRNA Exons, as well as cancer-associated protein markers that are specific for solid-tissue cancers and matched normal tissues. The present application teaches the art of selecting the desired number of markers and types of markers for both pan-oncology and specific cancers (i.e. colorectal cancer) to guide the physician to improve the treatment of the patient. Details on primer design and optimized primer sequences are provided to enable rapid validation of these tests for both pan-oncology and specific cancers. The two-step procedure is designed to cast a wide net to initially identify most of the individuals harboring an early cancer, followed by a more stringent second step to improve specificity and narrow the patients to those most likely to harbor a hidden cancer, who are then sent for imaging and followup. The advantage of this 2-step approach is that it not only identifies the potential tissue of origin, but it is designed to provide the highest positive predictive value (PPV). Thus, when a result for a rare cancer comes back as presumptive positive (i.e. early ovarian cancer) the physician can focus her attention on providing imaging and followup to those patients who need it the most, while the test minimizes the false-positives that create unnecessary anxiety and unwanted invasive procedures.
The present application provides robust approaches for detecting methylation and hydroxymethylation markers of cancer using either qPCR or dPCR readout using protocols that are amenable to automation and work on readily available commercial instruments. The approach provides advantages in being integrated and convenient for laboratory setup, allowing for cost reduction, scalability, and fit with medical and laboratory flow in a CLIA-compatible automated setting. The benefit in lives saved world-wide would be of incalculable value.
The most cost-effective early cancer detection test may combine an initial multiplexed coupled amplification and ligation assay to determine “cancer load”. For early cancer detection, this would achieve >95% sensitivity for all cancers (pan-oncology), at >97% specificity. These design principles may also be extended to include monitoring the efficacy of treatment, as well as detecting early cancer recurrence.
Several flow charts for cancer tumor load assays are illustrated in
In an advanced version of the test, a two-step assay would be performed to identify if the patient has colorectal cancer. The rationale for a two-step test is to initially cast a wide net to maximize sensitivity in identifying the most individuals with potential cancer, followed by a second step only on the positive samples (which contain both true and false-positives) to maximize specificity, eliminate virtually all the false-positives and hone in on those individuals most likely to have cancer. In the first step, a blood sample is fractionated into plasma and other components as needed, followed by an assay to interrogate an initial set of 12 markers with an average sensitivity of 75% (
For higher accuracy of the one step CRC test, after fractionating the blood sample, a set of 18 markers with average sensitivity of 75% are assayed, and the results are recorded (
For higher accuracy of the two step CRC test, after fractionating the blood sample, a set of 18 markers with average sensitivity of 75% are assayed, and the results are recorded (
In a pan-oncology version of the test, in the first step the assay would screen 96 markers, wherein on average ≥36 such markers would exhibit an average sensitivity of 50% for most major cancers (see
In a variation of the pan-oncology test, in the first step the assay would screen 96 markers, wherein on average ≥36 such markers would exhibit an average sensitivity of 50% for most major cancers (see
In a more streamlined version of the pan-oncology test, in the first step the assay would screen 48 markers, wherein on average ≥24 such markers would exhibit an average sensitivity of 75% for most major cancers (a pan-oncology test, see
The aforementioned 5 groups of 48 markers, with average sensitivity of 75% were designed to also be used to monitor treatment (see
The aforementioned 5 groups of 48 markers were designed to also be used to monitor for recurrence (see
The present application is directed to a universal diagnostic approach that seeks to combine the best features of digital polymerase chain reaction (PCR), or quantitative polymerase chain reaction (qPCR), with using TET1 and pyridine-borane for conversion of 5mC (5-methyl cytosine) and 5hmC (5-hydroxy-methyl cytosine) to DHU (dihydrouracil) (Liu et al., “Bisulfite-Free Direct Detection of 5-Methylcytosine and 5-Hydroxymethylcytosine at Base Resolution,” Nat. Biotechnol. 37:424-429 (2019), which is hereby incorporated by reference in its entirety), ligation detection reaction (LDR), and quantitative detection of multiple disease markers, e.g., cancer markers.
There is a technical challenge of distinguishing true signal generated from the desired disease-specific nucleic acid differences vs. false signal generated from normal nucleic acids present in the sample vs. false signal generated in the absence of the disease-specific nucleic acid differences (i.e. somatic mutations).
A number of solutions to these challenges are presented below, but they share some common themes.
The first theme is multiplexing. PCR works best when primer concentration is relatively high, from 50 nM to 500 nM, limiting multiplexing. Further, the more PCR primer pairs added, the chances of amplifying incorrect products or creating primer-dimers increase exponentially. In contrast, for LDR probes, low concentrations on the order of 4 nM to 20 nM are used, and probe-dimers are limited by the requirement for adjacent hybridization on the target to allow for a ligation event. Use of low concentrations of gene-specific PCR primers or LDR probes containing universal primer sequence “tails” allows for subsequent addition of higher concentrations of universal primers to achieve proportional amplification of the initial PCR or LDR products. Another way to avoid or minimize false PCR amplicons or primer dimers is to use PCR primers containing a few extra bases and a blocking group, which is liberated to form a free 3′OH by cleavage with a nuclease only when hybridized to the target, e.g., a ribonucleotide base as the blocking group and RNase H2 as the cleaving nuclease.
The second theme is fluctuations in signal due to low input target nucleic acids. Often, the target nucleic acid originated from a few cells, either captured as CTCs, or from tumor cells that underwent apoptosis and released their DNA as small fragments (140-160 bp) in the serum. Under such conditions, it is preferable to perform some level of proportional amplification to avoid missing the signal altogether or reporting inaccurate copy number due to fluctuations when distributing small numbers of starting molecules into individual wells (for real-time, or droplet PCR quantification). As long as these initial amplifications are kept at a reasonable level (approximately 12 to 20 cycles), the risk of carryover contamination during opening of the tube and distributing amplicons for subsequent detection/quantification (using real-time, or droplet PCR) is minimized Other schemes use even lower amounts of limited amplifications (approximately 8 to 12 cycles).
The third theme is target-independent signal, also known as “No Template Control” (NTC). This arises from either polymerase or ligase reactions that occur in the absence of the correct target. Some of this signal may be minimized by judicious primer design. For ligation reactions, the 5′ 4 3′ nuclease activity of polymerase may be used to liberate the 5′ phosphate of the downstream ligation primer (only when hybridized to the target), so it is suitable for ligation. Further specificity for distinguishing presence of a low-level mutation using LDR may be achieved by: (i) using upstream mutation-specific LDR probes containing a mismatch in the 2nd or 3rd position from the 3′OH base, (ii) using LNA or PNA probes to wild-type sequence that would reduce hybridization of mutation-specific LDR probes to wild-type sequences, (iii) using LDR probes to wild-type sequence that (optionally) ligate but do not undergo additional amplification, and (iv) using upstream LDR probes containing a few extra bases and a blocking group, which is liberated to form a free 3′OH by cleavage with a nuclease only when hybridized to the complementary target (e.g., RNase H2 and a ribonucleotide base). Similar approaches for improving the specificity for distinguishing presence of a low-level mutation using PCR may be achieved by: (i) using mutation-specific PCR primers containing a mismatch in the 2nd or 3rd position from the 3′OH base, (ii) using LNA or PNA probes to wild-type sequence that would reduce hybridization of mutation-specific PCR primers to wild-type sequences, (iii) using PCR primers to wild-type sequence that are blocked and do not undergo additional amplification, and (iv) using upstream PCR primers containing a few extra bases and a blocking group, which is liberated to form a free 3′OH by cleavage with a nuclease only when hybridized to the complementary target (e.g., RNase H2 and a ribonucleotide base).
The fourth theme is either suppressed (reduced) amplification or incorrect (false) amplification due to unused primers in the reaction. One approach to eliminate such unused primers is to capture genomic or target or amplified target DNA on a solid support, allow ligation probes to hybridize and ligate, and then remove probes or products that are not hybridized. Alternative solutions include pre-amplification, followed by subsequent nested LDR and/or PCR steps, such that there is a second level of selection in the process.
The fifth theme is carryover prevention. Carryover signal may be eliminated by standard uracil incorporation during the universal PCR amplification step, and by using UDG (and optionally AP endonuclease) in the pre-amplification workup procedure. Incorporation of carryover prevention is central to the methods of the present application as described in more detail below. The initial PCR amplification is performed using incorporation of uracil. The LDR reaction is performed with LDR probes lacking uracil. Thus, when the LDR products are subjected to real-time PCR quantification, addition of UDG destroys the initial PCR products, but not the LDR products. Further, since LDR is a linear process and the tag primers use sequences absent from the human genome, accidental carryover of LDR products back to the original PCR will not cause template-independent amplification. Additional schemes to provide carryover prevention with methylated targets include use of restriction endonucleases to destroy unmethylated DNA prior to PCR amplification, or by capturing and enriching methylated DNA using methyl-specific DNA binding proteins or antibodies.
The sixth theme is achieving even amplification of many mutation-specific or methylation-specific targets in the multiplexed reaction. One approach, as already described above, is to perform limited initial PCR amplifications (8 to 12, or 12 to 20 cycles). However, sometimes different products amplify at different rates, especially when using mutation- or methylation-specific primers, or when using blocking LNA or PNA probes or other means to suppress amplification of wild-type DNA. This is because a regular PCR reaction has both forward and reverse primers working simultaneously. Although there may be preferential amplification using as an example a forward methylation-specific primer (i.e. after using TET1 and pyridine-borane treatment), the reverse primer will amplify both methylated and un-methylated DNA (again, after using TET1 and pyridine-borane treatment), and thus will magnify differences in initial rates of forward primer amplification. Further, and this also holds when using mutation-specific forward primers, the use of non-selecting reverse primers means that initial amplification products still contain substantial amounts of wild-type DNA sequence, which may lead to undesired false-positives in subsequent amplification steps. One approach is to perform an initial single-sided linear amplification, using primers that amplify only one strand of target DNA. This is particularly useful when amplifying TET1 and pyridine-borane-treated DNA, where the two resultant strands are no longer complementary to each other. An important variation of this theme destroys the initial target DNA after the linear amplification step. This may be achieved by incorporating one or more modified nucleotides, such as α-thio-dNTPs, that protect the initial extension products (but not the original cfDNA or genomic DNA) from exonuclease I digestion.
A first aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences of other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences of other parent nucleic acid molecules by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are then provided. One or more primary oligonucleotide primer sets are also provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the target nucleotide sequence and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises of a 5′ primer-specific portion. The sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles. The one or more polymerase extension reaction cycles comprise a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising nucleotide sequences complementary to the target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixtures, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The method further comprises subjecting the one or more first polymerase chain reaction mixtures to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase chain reaction mixtures and for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the target nucleotide sequence or a complement thereof. One or more oligonucleotide probe sets are then provided. Each probe set comprises (a) a first oligonucleotide probe having a 5′ primer-specific portion and a 3′ target sequence-specific portion, and (b) a second oligonucleotide probe having a 5′ target sequence-specific portion and a 3′ primer-specific portion, wherein the first and second oligonucleotide probes of a probe set are configured to hybridize, in a base specific manner, on a complementary target nucleotide sequence of a first polymerase chain reaction product. The first polymerase chain reaction products are blended with a ligase, and the one or more oligonucleotide probe sets to form one or more ligation reaction mixtures. The one or more ligation reaction mixtures are subjected to one or more ligation reaction cycles whereby the first and second oligonucleotide probes of the one or more oligonucleotide probe sets are ligated together, when hybridized to their complementary sequence, to form ligated product sequences in the ligation reaction mixtures wherein each ligated product sequence comprises the 5′ primer-specific portion, the target-specific portions, and the 3′ primer-specific portion. The method further includes providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the ligated product sequence and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the ligated product sequence. The ligated product sequences, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further comprises detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues.
As shown in
As shown in
As shown in
In this embodiment, the ligation probes are designed to contain UniTaq primer and tag sequences to facilitate detections. The UniTaq system is fully described in U.S. Patent Application Publication No. 2011/0212846 to Spier, which is hereby incorporated by reference in its entirety. The UniTaq system involves the use of three unique “tag” sequences, where at least one of the unique tag sequences (Ai) is present in the first oligonucleotide probe, and the second and third unique tag portions (Bi′ and Ci′) are in the second oligonucleotide probe sequence as shown in
Prior to detecting the ligation product, the sample is treated with UDG to destroy original target amplicons allowing only authentic ligation products to be detected. Following ligation, the ligation products are aliquoted into separate wells, micro-pores or droplets containing one or more tag-specific primer pairs. For the detection step, the ligation product containing Ai (a first primer-specific portion), Bi′ (a UniTaq detection portion), and Ci′ (a second primer-specific portion) is primed on both strands using a first oligonucleotide primer having the same nucleotide sequence as Ai, and a second oligonucleotide primer that is complementary to Ci′ (i.e., Ci). The first oligonucleotide primer also includes a UniTaq detection probe (Bi) that has a detectable label Fl on one end and a quencher molecule (Q) on the other end (Fl-Bi-Q-Ai). Optionally positioned proximal to the quencher is a polymerase-blocking unit, e.g., HEG, THF, Sp-18, ZEN, or any other blocker known in the art that is sufficient to stop polymerase extension. In another embodiment, a ZEN quencher group is also positioned about 9 bases from the fluorescent reporter group to assure more complete quenching. PCR amplification results in the formation of double stranded products as shown in
The double stranded PCR products are denatured, and when the temperature is subsequently decreased, the upper strand of product forms a hairpin having a stem between the 5′ portion (Bi) of the first oligonucleotide primer and portion Bi′ at the opposite end of the strand (
The ligation reaction used in the methods of the present application is well known in the art. Ligases suitable for ligating oligonucleotide probes of a probe set together (optionally following cleavage of a 3′ ribose and blocking group on the first oligonucleotide probe, or the 5′ flap on the second oligonucleotide probe) include, without limitation Thermus aquaticus ligase, E. coli ligase, T4 DNA ligase, T4 RNA ligase, Taq ligase, 9 N ligase, and Pyrococcus ligase, or any other thermostable ligase known in the art. In accordance with the present application, the nuclease-ligation process of the present application can be carried out by employing an oligonucleotide ligation assay (OLA) reaction (see Landegren, et al., “A Ligase-Mediated Gene Detection Technique,” Science 241:1077-80 (1988); Landegren, et al., “DNA Diagnostics—Molecular Techniques and Automation,” Science 242:229-37 (1988); and U.S. Pat. No. 4,988,617 to Landegren et al., which are hereby incorporated by reference in their entirety), a ligation detection reaction (LDR) that utilizes one set of complementary oligonucleotide probes (see e.g., WO 90/17239 to Barany et al., which is hereby incorporated by reference in its entirety), or a ligation chain reaction (LCR) that utilizes two sets of complementary oligonucleotide probes see e.g., WO 90/17239 to Barany et al., which is hereby incorporated by reference in its entirety).
The oligonucleotide probes of a probe sets can be in the form of ribonucleotides, deoxynucleotides, modified ribonucleotides, modified deoxyribonucleotides, peptide nucleotide analogues, modified peptide nucleotide analogues, modified phosphate-sugar-backbone oligonucleotides, nucleotide analogs, and mixtures thereof.
The hybridization step in the ligase detection reaction, which is preferably a thermal hybridization treatment, discriminates between nucleotide sequences based on a distinguishing nucleotide at the ligation junctions. The difference between the target nucleotide sequences can be, for example, a single nucleic acid base difference, a nucleic acid deletion, a nucleic acid insertion, or rearrangement. Such sequence differences involving more than one base can also be detected. Preferably, the oligonucleotide probe sets have substantially the same length so that they hybridize to target nucleotide sequences at substantially similar hybridization conditions.
Ligase discrimination can be further enhanced by employing various probe design features. For example, an intentional mismatch or nucleotide analogue (e.g., Inosine, Nitroindole, or Nitropyrrole) can be incorporated into the first oligonucleotide probe at the 2nd or 3rd base from the 3′ junction end to slightly destabilize hybridization of the 3′ end if it is perfectly matched at the 3′ end, but significantly destabilize hybridization of the 3′ end if it is mis-matched at the 3′ end. This design reduces inappropriate misligations when mutant probes hybridize to wild-type target. Alternatively, RNA bases that are cleaved by RNases can be incorporated into the oligonucleotide probes to ensure template-dependent product formation. For example, Dobosy et al., “RNase H-Dependent PCR (rhPCR): Improved Specificity and Single Nucleotide Polymorphism Detection Using Blocked Cleavable Primers,” BMC Biotechnology 11(80):1011 (2011), which is hereby incorporated by reference in its entirety, describes using an RNA-base close to the 3′ end of an oligonucleotide probe with 3′-blocked end, and cutting it with RNase H2 generating a PCR-extendable and ligatable 3′-OH. This approach can be used to generate either ligation-competent 3′OH (for standard DNA ligases), or 5′-P, or both, in the latter case, provided a ligase that can ligate 5′-RNA base is utilized.
Other possible modifications included abasic sites, e.g., internal abasic furan or oxo-G. These abnormal “bases” are removed by specific enzymes to generate ligation-competent 3′-OH or 5′P sites. Endonuclease IV, Tth EndolV (NEB) will remove abasic residues after the ligation oligonucleotides anneal to the target nucleic acid, but not from a single-stranded DNA. Similarly, one can use oxo-G with Fpg or inosine/uracil with EndoV or Thymine glycol with EndoVIII.
Ligation discrimination can also be enhanced by using the coupled nuclease-ligase reaction described in WO2013/123220 to Barany et al. or U.S. Patent Application Publication No. 2006/0234252 to Anderson et al., which are hereby incorporated by reference in their entirety. In this embodiment, the first oligonucleotide probe bears a ligation competent 3′ OH group while the second oligonucleotide probe bears a ligation incompetent 5′ end (i.e., an oligonucleotide probe without a 5′ phosphate). The oligonucleotide probes of a probe set are designed such that the 3′-most base of the first oligonucleotide probe is overlapped by the immediately flanking 5′-most base of the second oligonucleotide probe that is complementary to the target nucleic acid molecule. The overlapping nucleotide is referred to as a “flap”. When the overlapping flap nucleotide of the second oligonucleotide probe is complementary to the target nucleic acid molecule sequence and the same sequence as the terminating 3′ nucleotide of the first oligonucleotide probe, the phosphodiester bond immediately upstream of the flap nucleotide of the second oligonucleotide probe is discriminatingly cleaved by an enzyme having flap endonuclease (FEN) or 5′ nuclease activity. That specific FEN activity produces a novel ligation competent 5′ phosphate end on the second oligonucleotide probe that is precisely positioned alongside the adjacent 3′ OH of the first oligonucleotide probe to allow ligation of the two probes to occur. In accordance with this embodiment, flap endonucleases or 5′ nucleases that are suitable for cleaving the 5′ flap of the second oligonucleotide probe prior to ligation include, without limitation, polymerases with 5′ nuclease activity such as E. coli DNA polymerase and polymerases from Taq and T. thermophilus, as well as T4 RNase H. In another embodiment, the second probe of the probe set has a 3′ primer-specific portion, a target specific portion, and a 5′ nucleotide sequence, where the 5′ nucleotide sequence is complementary to at least a portion of the 3′ primer-specific portion, and where the 5′ nucleotide sequence hybridizes to its complementary portion of the 3′ primer-specific portion to form a hair-pinned second oligonucleotide probe when the second probe is not hybridized to a target nucleotide sequence.
For insertions or deletions, incorporation of a matched base or nucleotide analogues (e.g., -amino-dA or 5-propynyl-dC) in the first oligonucleotide probe at the 2nd or 3rd position from the junction improves stability and may improve discrimination of such frameshift mutations from wild-type sequences. For insertions, use of one or more thiophosphate-modified nucleotides downstream from the desired scissile phosphate bond of the second oligonucleotide probe will prevent inappropriate cleavage by the 5′ nuclease enzyme when the probes are hybridized to wild-type DNA, and thus reduce false-positive ligation on wild-type target. Likewise, for deletions, use of one or more thiophosphate-modified nucleotides upstream from the desired scissile phosphate bond of the second oligonucleotide probe will prevent inappropriate cleavage by the 5′ nuclease enzyme when the probes are hybridized to wild-type DNA, and thus reduce false-positive ligation on wild-type target.
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences of other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences of other parent nucleic acid molecules by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules and one or more nucleases capable of digesting nucleic acid molecules present not comprising polymerase-incorporated modified nucleotides are provided. The method also involves providing one or more primary oligonucleotide primer sets. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the target nucleotide sequence and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The sample, the one or more first primary oligonucleotide primers, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix that comprises one or more modified nucleotides that protect extension products but not other DNA from nuclease digestion, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising modified nucleotide bases and comprising the complement of the target nucleotide sequence. The method comprises blending the one or more polymerase extension reaction mixtures comprising the primary extension products with the one or more nucleases. The one or more polymerase extension reaction mixtures comprising the primary extension products with the one or more nucleases are subjected to conditions suitable for digesting nucleic acid molecules but not primary extension products comprising modified nucleotides to produce one or more partially digested polymerase extension reaction mixtures. The method further comprises blending the one or more partially digested polymerase extension reaction mixtures, the one or more secondary primary oligonucleotide primers of the primer sets, a deoxynucleotide mix, and a DNA polymerase to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out two or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the target nucleotide sequence or a complement thereof. One or more secondary oligonucleotide primer sets are then provided. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 3′ portion that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first secondary oligonucleotide primer. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU) containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out two or more second polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further comprises detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more nucleotides, one or more copy numbers, one or more transcript sequences, and/or one or more methylated or hydroxymethylated residues.
The method also optionally involves providing one or more universal primers comprising the same nucleotide sequence as the 5′ primer-specific portion of one of the primary oligonucleotide primers.
In some embodiments, the second secondary oligonucleotide primer is substantially similar to or even identical to the first primary oligonucleotide primer.
After the initial extension and exonuclease treatment, locus-specific primers comprising 5′ universal primer sequences and 3′ target-specific sequences, are added to enable limited cycle PCR. Optionally, one or more universal primers are also added. In this embodiment, another layer of selectivity can be incorporated into the method by including a 3′ cleavable blocking group (Blk 3′, e.g. C3 spacer), and an RNA base (r), in the upstream primer. Upon target-specific hybridization, RNase H (star symbol) removes the RNA base to liberate a 3′OH group which is a few bases upstream of the mutation, and suitable for polymerase extension (
There are several different types of blocking groups that prevent extension of the 3′ end of an oligonucleotide primer by polymerase, ranging from a simple dideoxynucleotide, to different spacer moieties such as Spacer 18 or Spacer C3, to common 3′ labels such as Biotin TEG or fluorescein, to one or more 2′-O-methyl uracil bases. Some of these moieties are known to provide resistance to digestion by exonuclease I (i.e. Spacer C3, [2′-O-methyl-U]4, or Biotin TEG), while others are known to be sensitive or only partially resistant (dideoxynucleotide, Spacer 18, or 3′-fluorescein). If a blocking group is used that permits exonuclease I digestion to also destroy the initial upstream primers, this allows for a controlled linear-linear type amplification. For example, if the initial extension generates 20 copies of each target molecule, then destroying the upstream primers prior to adding the downstream primers would allow generation of 400 copies of each target molecule. This approach has the advantage of providing a more even linear-linear amplification of multiple markers simultaneously. It may be used for the exPCR-qPCR strategies illustrated in
As shown in
As shown in
The initial extension products incorporate one or more modified nucleotides, such as α-thio-dNTPs, that protect the initial extension products (but not the original cfDNA or genomic DNA) from exonuclease I digestion (
After the initial extension and exonuclease treatment, locus-specific primers comprising 5′ universal primer sequences and 3′ target-specific sequences, are added to enable limited cycle PCR. Optionally, one or more universal primers are also added. In this embodiment, another layer of selectivity can be incorporated into the method by including a 3′ cleavable blocking group (Blk 3′, e.g. C3 spacer), and an RNA base (r), in the upstream primer. Upon target-specific hybridization, RNase H (star symbol) removes the RNA base to liberate a 3′OH group which is a few bases upstream of the mutation, and suitable for polymerase extension (
As shown in
As shown in
The double stranded PCR products are denatured, and when the temperature is subsequently decreased, the upper strand of product forms a hairpin having a stem between the 5′ portion (Bi) of the first oligonucleotide primer and portion Bi′ at the opposite end of the strand (
The aforementioned examples in
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues and subjecting the nucleic acid molecules in the sample to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are then provided. The method further involves providing one or more primary oligonucleotide primer sets. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The treated sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the primer sets, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. The method further involves providing one or more oligonucleotide probe sets. Each probe set comprises (a) a first oligonucleotide probe having a 5′ primer-specific portion and a 3′ DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and (b) a second oligonucleotide probe having a 5′ DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion and a 3′ primer-specific portion, and wherein the first and second oligonucleotide probes of a probe set are configured to hybridize, in a base specific manner, on a complementary nucleotide sequence of a first polymerase chain reaction product. The first polymerase chain reaction products are blended with a ligase and the one or more oligonucleotide probe sets to form one or more ligation reaction mixtures. The one or more ligation reaction mixtures are subjected to one or more ligation reaction cycles whereby the first and second oligonucleotide probes of the one or more oligonucleotide probe sets are ligated together, when hybridized to their complementary sequence, to form ligated product sequences in the ligation reaction mixture wherein each ligated product sequence comprises the 5′ primer-specific portion, DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and the 3′ primer-specific portion. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the ligated product sequence and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the ligated product sequence. The ligated product sequences, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures, and the one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Alternatively, as shown in
For
Alternatively, methylation-specific upstream and locus-specific downstream probes containing tails (Ai, Bi′-Ci′) enable formation of a ligation product in the presence of TET1, pyridine-borane converted methylated (or hydroxymethylated) base-containing PCR products. Following ligation, the ligation products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other parent nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules are provided, and one or more first primary oligonucleotide primer(s) that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more methylated or hydroxymethylated residue are also provided. The treated sample, the one or more first primary oligonucleotide primers, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that is complementary to a portion of the polymerase extension product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first secondary oligonucleotide primer. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are then subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the first polymerase chain reaction mixtures, and conditions suitable for carrying out two or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising a 5′ primer-specific portion of the first secondary oligonucleotide primer, a DNA repair enzyme and chemically-treated target nucleotide sequence-specific or complement sequence-specific portion, and a complement of the 5′ primer-specific portion of the second secondary oligonucleotide primer. The method further involves providing one or more tertiary oligonucleotide primer sets. Each tertiary oligonucleotide primer set comprises (a) a first tertiary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the first polymerase chain reaction products and (b) a second tertiary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the first polymerase chain reactions product sequence. The first polymerase chain reaction products, the one or more tertiary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU) containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Alternatively, as shown in
As shown in
Alternatively, TET1, pyridine-borane converted methylation base-specific primers (comprising 5′ primer-specific portions Ai) and TET1, pyridine-borane converted locus-specific primers (comprising 5′ primer-specific portions Bi-Ci) are added to then perform limited cycle nested PCR to amplify the TET1, pyridine-borane converted methylation-containing sequence, if present in the sample. Optional blocking LNA or PNA probes comprising the wild-type sequence (or its complement) enables amplification of originally methylated but not originally un-methylated allele. Primers are unblocked with RNaseH2 only when bound to correct target. Following PCR, the products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules present in the sample are provided, and one or more primary oligonucleotide primer sets are provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer, wherein the first or second primary oligonucleotide primer further comprises a 5′ primer-specific portion. The treated sample, the one or more first primary oligonucleotide primers of the primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the extension reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The one or more first polymerase chain reaction mixtures are subjected to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reaction products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. The method further comprises providing one or more secondary oligonucleotide primer sets. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer having a 3′ portion that is complementary to a portion of a first polymerase chain reaction product formed from the first primary oligonucleotide primer and (b) a second secondary oligonucleotide primer having a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of a first polymerase chain reaction product formed from the first secondary oligonucleotide primer. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out two or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reactions products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
Following the limited cycle PCR, the PCR products are aliquoted into separate wells, micro-pores or droplets containing Taqman™ probes, TET1, pyridine-borane converted, methylation base-specific, and TET1, pyridine-borane converted locus-specific primers, to amplify the TET1, pyridine-borane converted methylation-containing sequence, if present in the sample (
Alternatively, as shown in
For the protocol illustrated in
Alternatively, following the limited cycle PCR, the PCR products are aliquoted into separate wells, micro-pores or droplets containing Taqman™ probes, TET1, pyridine-borane converted methylation base-specific primers comprising 5′ primer-specific portions (Ai), TET1, pyridine-borane converted locus-specific primers comprising 5′ primer-specific portions (Bi-Ci) and matching UniTaq primers Fl-Bi-Q-Ai and Ci. Optional blocking LNA or PNA probes comprising the wild-type sequence (or its complement) enables amplification of originally methylated but not originally un-methylated allele. Primers are unblocked with RNaseH2 only when bound to correct target. Following PCR, the products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Alternatively, as shown in
For
Alternatively, methylation-specific upstream and locus-specific downstream probes containing tails (Ai, Bi′-Ci′) enable formation of a ligation product in the presence of TET1, pyridine-borane converted methylated base-containing PCR products. Following ligation, the ligation products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Alternatively, as shown in
As shown in
Alternatively, TET1, pyridine-borane converted methylation base-specific primers (comprising 5′ primer-specific portions Ai) and TET1, pyridine-borane converted locus-specific primers (comprising 5′ primer-specific portions Bi-Ci) are added to then perform limited cycle nested PCR to amplify the TET1, pyridine-borane converted methylation-containing sequence, if present in the sample. Primers are unblocked with RNaseH2 only when bound to correct target. Following PCR, the products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Following the limited cycle PCR, the PCR products are aliquoted into separate wells, micro-pores or droplets containing Taqman™ probes, TET1, pyridine-borane converted, methylation base-specific, and TET1, pyridine-borane converted locus-specific primers, to amplify the TET1, pyridine-borane converted methylation-containing sequence, if present in the sample (
For the protocol illustrated in
Alternatively, following the limited cycle PCR, the PCR products are aliquoted into separate wells, micro-pores or droplets containing Taqman™ probes, TET1, pyridine-borane converted methylation base-specific primers comprising 5′ primer-specific portions (Ai), TET1, pyridine-borane converted locus-specific primers comprising 5′ primer-specific portions (Bi-Ci) and matching UniTaq primers Fl-Bi-Q-Ai and Ci. Primers are unblocked with RNaseH2 only when bound to correct target. Following PCR, the products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
Another aspect of the present application is directed to a method for identifying, in a sample, one or more parent nucleic acid molecules containing a target nucleotide sequence differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues. The method involves providing a sample containing one or more parent nucleic acid molecules potentially containing the target nucleotide sequence differing from the nucleotide sequences in other nucleic acid molecules by one or more methylated or hydroxymethylated residues. The nucleic acid molecules in the sample are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues to produce a treated sample. One or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules present in the sample are provided. One or more primary oligonucleotide primer sets are also provided. Each primary oligonucleotide primer set comprises (a) a first primary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a sequence in the parent nucleic acid molecule adjacent to the DNA repair enzyme and chemically-treated target nucleotide sequence containing the one or more converted methylated or hydroxymethylated residue and (b) a second primary oligonucleotide primer having a 5′ primer-specific portion and a 3′ portion that comprises a nucleotide sequence that is complementary to a portion of an extension product formed from the first primary oligonucleotide primer. The treated sample, the one or more first primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more polymerase extension reaction mixtures. The one or more polymerase extension reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising the complement of the DNA repair enzyme and chemically-treated target nucleotide sequence. The one or more polymerase extension reaction mixtures comprising the primary extension products, the one or more second primary oligonucleotide primers of the one or more primary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules in the reaction mixture, a deoxynucleotide mix, and a DNA polymerase are blended to form one or more first polymerase chain reaction mixtures. The method further comprises subjecting the one or more first polymerase chain reaction mixtures to conditions suitable for carrying out one or more first polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming first polymerase chain reactions products comprising the DNA repair enzyme and chemically-treated target nucleotide sequence or a complement thereof. One or more secondary oligonucleotide primer sets are provided. Each secondary oligonucleotide primer set comprises (a) a first secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the first polymerase chain reaction products or their complements and (b) a second secondary oligonucleotide primer comprising a nucleotide sequence that is complementary to the 3′ primer-specific portion of the first polymerase chain reaction products or their complements. The first polymerase chain reaction products, the one or more secondary oligonucleotide primer sets, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, a deoxynucleotide mix including dUTP, and a DNA polymerase are blended to form one or more second polymerase chain reaction mixtures. The one or more second polymerase chain reaction mixtures are subjected to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the second polymerase chain reaction mixtures and for carrying out one or more polymerase chain reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment thereby forming second polymerase chain reaction products. The method further involves detecting and distinguishing the second polymerase chain reaction products in the one or more second polymerase chain reaction mixtures to identify the presence of one or more parent nucleic acid molecules containing target nucleotide sequences differing from nucleotide sequences in other parent nucleic acid molecules in the sample by one or more methylated or hydroxymethylated residues.
As shown in
Alternatively, the limited cycle PCR products comprise of Ai tag sequence, methylation-specific sequence, and Bi′-Ci′ tag sequence, and are distributed into wells, micro-pores, or droplets for Taqman™ reactions. Following PCR, the products are amplified using UniTaq-specific primers (i.e., Fl-Bi-Q-Ai, Ci) and detected as described supra for
In one embodiment, the methods described supra further comprise contacting the sample with DNA repair enzymes to repair damaged DNA, abasic sites, oxidized bases, or nicks in the DNA.
In certain embodiments, the sample is contacted with at least a first methylation sensitive enzyme to form a restriction enzyme reaction mixture prior to, or concurrent with, the blending step to form one or more polymerase extension reaction mixtures, wherein the first methylation sensitive enzyme cleaves nucleic acid molecules in the sample that contain one or more unmethylated residues within at least one methylation sensitive enzyme recognition sequence, and whereby the detecting involves detection of one or more parent nucleic acid molecules containing the target nucleotide sequence, wherein the parent nucleic acid molecules originally contained one or more methylated or hydroxymethylated residues.
In accordance with this and all aspects of the present invention, a “methylation sensitive enzyme” is an endonuclease that will not cleave or has reduced cleavage efficiency of its cognate recognition sequence in a nucleic acid molecule when the recognition sequence contains a methylated residue (i.e., it is sensitive to the presence of a methylated residue within its recognition sequence). A “methylation sensitive enzyme recognition sequence” is the cognate recognition sequence for a methylation sensitive enzyme. In some embodiments, the methylated residue is a 5-methyl-C, within the sequence CpG (i.e., 5-methyl-CpG). A non-limiting list of methylation sensitive restriction endonuclease enzymes that are suitable for use in the methods of the present invention include, without limitation, AciI, HinP1I, Hpy99I, HpyCH4IV, BstUI, HpaII, HhaI, or any combination thereof.
In certain embodiments, the sample is contacted with an immobilized methylated or hydroxymethylated nucleic acid binding protein or antibody to selectively bind and enrich for methylated or hydroxymethylated nucleic acid in the sample.
In another embodiment, one or more primary or secondary oligonucleotide primers comprises a portion that has no or one nucleotide sequence mismatch when hybridized in a base-specific manner to the target nucleic acid sequence or DNA repair enzyme and chemically-treated methylated or hydroxymethylated nucleic acid sequence or complement sequence thereof, but have one or more additional nucleotide sequence mismatches that interferes with polymerase extension when said primary or secondary oligonucleotide primers hybridize in a base-specific manner to a corresponding nucleotide sequence portion in wild-type nucleic acid sequence or complement sequence thereof.
In another embodiment, one or both primary oligonucleotide primers of the primary oligonucleotide primer set and/or one or both secondary oligonucleotide primers of the secondary oligonucleotide primer set have a 3′ portion comprising a cleavable nucleotide or nucleotide analogue and a blocking group, such that the 3′ end of the primer or primers is unsuitable for polymerase extension. This also involves cleaving the cleavable nucleotide or nucleotide analog of one or both oligonucleotide primers during the hybridization treatment, thereby liberating free 3′OH ends on one or both oligonucleotide primers prior to the extension treatment.
In accordance with this embodiment, one or more primary or secondary oligonucleotide primers may comprise a sequence that differs from the target nucleic acid sequence or DNA repair enzyme and chemically-treated methylated or hydroxymethylated nucleic acid sequence or complement sequence thereof, said difference is located two or three nucleotide bases from the liberated free 3′OH end.
The cleavable nucleotide may also comprise one or more RNA bases.
In another embodiment, the methods described supra further comprise providing one or more blocking oligonucleotide primers comprising one or more mismatched bases at the 3′ end or one or more nucleotide analogs and a blocking group at the 3′ end, such that the 3′ end of said blocking oligonucleotide primer is unsuitable for polymerase extension when hybridized in a base-specific manner to wild-type nucleic acid sequence or complement sequence thereof, wherein the blocking oligonucleotide primer comprises a portion having a nucleotide sequence that is the same as a nucleotide sequence portion in the wild-type nucleic acid sequence or complement sequence thereof to which the blocking oligonucleotide primer hybridizes but has one or more nucleotide sequence mismatches to a corresponding nucleotide sequence portion in the target nucleic acid sequence or DNA repair enzyme and chemically-treated methylated or hydroxymethylated nucleic acid sequence or complement sequence thereof. The one or more blocking oligonucleotide primers may be blended with the sample or products subsequently produced from the sample prior to a polymerase extension reaction, polymerase chain reaction, or ligation reaction, whereby during the hybridization step the one or more blocking oligonucleotide primers preferentially hybridize in a base-specific manner to a wild-type nucleic acid sequence or complement sequence thereof, thereby interfering with polymerase extension or ligation during reaction of a primer or probes hybridized in a base-specific manner to the wild-type sequence or complement sequence thereof.
In certain embodiments, the first secondary oligonucleotide primer has a 5′ primer-specific portion and the second secondary oligonucleotide primer has a 5′ primer-specific portion, said one or more secondary oligonucleotide primer sets further comprising a third secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the first secondary oligonucleotide primer and (d) a fourth secondary oligonucleotide primer comprising the same nucleotide sequence as the 5′ primer-specific portion of the second secondary oligonucleotide primer.
In certain embodiments, the methods described supra further comprise providing one or more third primary oligonucleotide primers comprising the same nucleotide sequence as the 5′ primer-specific portion of the first or second primary oligonucleotide primer, and blending the one or more third primary oligonucleotide primers in the one or more first polymerase chain reaction mixtures.
In other embodiments, the methods described supra further comprise providing one or more nucleases capable of digesting nucleic acid molecules present not comprising polymerase-incorporated modified nucleotides, providing a deoxynucleotide mix that comprises one or more modified nucleotides that protect extension product but not other DNA from nuclease digestion, blending the sample, the one or more first primary oligonucleotide primers, the one or more enzymes capable of digesting deoxyuracil (dU)-containing nucleic acid molecules, the deoxynucleotide mix that comprises one or more modified nucleotides that protect extension products but not target DNA from nuclease digestion, and a DNA polymerase to form one or more polymerase extension reaction mixtures, subjecting the one or more polymerase extension reaction mixtures to conditions suitable for digesting deoxyuracil (dU)-containing nucleic acid molecules present in the polymerase extension reaction mixtures and for carrying out one or more polymerase extension reaction cycles comprising a denaturation treatment, a hybridization treatment, and an extension treatment, thereby forming primary extension products comprising modified nucleotide bases and comprising the complement of the target nucleotide sequence, blending the polymerase extension reaction mixtures comprising the primary extension products, and the one or more nucleases, and subjecting the one or more polymerase extension reaction mixtures to conditions suitable for digesting nucleic acid molecules present in the polymerase extension reaction mixtures, but not primary extension products comprising modified nucleotides.
In certain embodiments, the DNA repair enzyme is the ten-eleven translocation (TET1) dioxygenase and the chemical treatment is with pyridine-borane.
In another embodiment, the second oligonucleotide probe of the oligonucleotide probe set further comprises a unitaq detection portion, thereby forming ligated product sequences comprising the 5′ primer-specific portion, the target-specific portions, the unitaq detection portion, and the 3′ primer-specific portion. This embodiment involves providing one or more unitaq detection probes, wherein each unitaq detection probe hybridizes to a complementary unitaq detection portion and said detection probe comprises a quencher molecule and a detectable label separated from the quencher molecule, adding the one or more unitaq detection probes to the second polymerase chain reaction mixture, and hybridizing the one or more unitaq detection probes to complementary unitaq detection portions on the ligated product sequence or complement thereof during said subjecting the second polymerase chain reaction mixture to conditions suitable for one or more polymerase chain reaction cycles, wherein the quencher molecule and the detectable label are cleaved from the one or more unitaq detection probes during the extension treatment and said detecting involves the detection of the cleaved detectable label.
In certain embodiments, one primary oligonucleotide primer or one secondary oligonucleotide primer further comprises a unitaq detection portion, thereby forming extension product sequences comprising the 5′ primer-specific portion, the target-specific portions, the unitaq detection portion, and the complement of the other 5′ primer-specific portion, and complements thereof. This embodiment comprises providing one or more unitaq detection probes, wherein each unitaq detection probe hybridizes to a complementary unitaq detection portion and the detection probe comprises a quencher molecule and a detectable label separated from the quencher molecule. The one or more unitaq detection probes are added to the one or more polymerase chain reaction mixtures, and the one or more unitaq detection probes are hybridized to complementary unitaq detection portions on the ligated product sequence or complement thereof during polymerase chain reaction cycles after the first polymerase chain reaction, wherein the quencher molecule and the detectable label are cleaved from the one or more unitaq detection probes during the extension treatment and said detecting involves the detection of the cleaved detectable label.
In one embodiment, one or both oligonucleotide probes of the oligonucleotide probe set comprises a portion that has no or one nucleotide sequence mismatch when hybridized in a base-specific manner to the target nucleic acid sequence or DNA repair enzyme and chemically-treated methylated or hydroxymethylated nucleic acid sequence or complement sequence thereof, but have one or more additional nucleotide sequence mismatches that interferes with ligation when said oligonucleotide probe hybridizes in a base-specific manner to a corresponding nucleotide sequence portion in the wild-type nucleic acid sequence or complement sequence thereof.
In another embodiment, the 3′ portion of the first oligonucleotide probe of the oligonucleotide probe set comprises a cleavable nucleotide or nucleotide analogue and a blocking group, such that the 3′ end is unsuitable for polymerase extension or ligation. This method further comprises cleaving the cleavable nucleotide or nucleotide analog of the first oligonucleotide probe when the probe is hybridized to its complementary target nucleotide sequence of the primary extension product, thereby liberating a 3′OH on the first oligonucleotide probe prior to said ligating.
The one or more first oligonucleotide probe of the oligonucleotide probe set may comprise a sequence that differs from the target nucleic acid sequence or DNA repair enzyme and chemically-treated methylated or hydroxymethylated nucleic acid sequence or complement sequence thereof, said difference is located two or three nucleotide bases from the liberated free 3′OH end.
In certain embodiments, the second oligonucleotide probe has, at its 5′ end, an overlapping identical nucleotide with the 3′ end of the first oligonucleotide probe, and, upon hybridization of the first and second oligonucleotide probes of a probe set at adjacent positions on a complementary target nucleotide sequence of a primary extension product to form a junction, the overlapping identical nucleotide of the second oligonucleotide probe forms a flap at the junction with the first oligonucleotide probe. This embodiment comprises cleaving the overlapping identical nucleotide of the second oligonucleotide probe with an enzyme having 5′ nuclease activity thereby liberating a phosphate at the 5′ end of the second oligonucleotide probe prior to said ligating.
In certain embodiments, the one or more oligonucleotide probe sets further comprise a third oligonucleotide probe having a target-specific portion, wherein the second and third oligonucleotide probes of a probe set are configured to hybridize adjacent to one another on the target nucleotide sequence with a junction between them to allow ligation between the second and third oligonucleotide probes to form a ligated product sequence comprising the first, second, and third oligonucleotide probes of a probe set.
In accordance with the methods described supra, the sample may be selected from the group consisting of tissue, cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, cell-free circulating nucleic acids, cell-free circulating tumor nucleic acids, cell-free circulating fetal nucleic acids in pregnant woman, circulating tumor cells, tumor, tumor biopsy, and exosomes.
The one or more target nucleotide sequences can be low-abundance nucleic acid molecules comprising one or more nucleotide base mutations, insertions, deletions, translocations, splice variants, mRNA, lncRNA, ncRNA, miRNA variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicing, exon insertions, exon deletions, intron insertions, or other rearrangement at the genome level and/or methylated or hydroxymethylated nucleotide bases.
These low-abundance nucleic acid molecules have one or more nucleotide base mutations, insertions, deletions, translocations, splice variants, mRNA, lncRNA, ncRNA, miRNA variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicings, exon insertions, exon deletions, intron insertions, or other rearrangement at the genome level, and/or methylated or hydroxymethylated nucleotide bases and are identified and distinguished from a high-abundance of nucleic acid molecules in the sample having a similar nucleotide sequence as the low abundance nucleic acid molecules but without the one or more nucleotide base mutations, insertions, deletions, translocations, splice variants, mRNA, lncRNA, ncRNA, miRNA variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicing, exon insertions, exon deletions, intron insertions, or other rearrangement at the genome level, and/or methylated or hydroxymethylated nucleotide bases.
As used herein “low abundance nucleic acid molecule” refers to a target nucleic acid molecule that is present at levels as low as 1% to 0.01% of the sample. In other words, a low abundance nucleic acid molecule with one or more nucleotide base mutations, insertions, deletions, translocations, splice variants, miRNA variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicings, exon insertions, exon deletions, intron insertions, other rearrangement at the genome level, and/or methylated nucleotide bases can be distinguished from a 100 to 10,000-fold excess of nucleic acid molecules in the sample (i.e., high abundance nucleic acid molecules) having a similar nucleotide sequence as the low abundance nucleic acid molecules but without the one or more nucleotide base mutations, insertions, deletions, translocations, splice variants, miRNA variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicings, exon insertions, exon deletions, intron insertions, other rearrangement at the genome level, and/or methylated nucleotide bases.
In some embodiments of the present invention, the copy number of one or more low abundance target nucleotide sequences are quantified relative to the copy number of high abundance nucleic acid molecules in the sample having a similar nucleotide sequence as the low abundance nucleic acid molecules. In other embodiments of the present invention, the one or more target nucleotide sequences are quantified relative to other nucleotide sequences in the sample. In other embodiments of the present invention, the relative copy number of one or more target nucleotide sequences is quantified. Methods of relative and absolute (i.e., copy number) quantitation are well known in the art.
The low abundance target nucleic acid molecules to be detected can be present in any biological sample, including, without limitation, tissue, cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, cell-free circulating nucleic acids, cell-free circulating tumor nucleic acids, cell-free circulating fetal nucleic acids in pregnant woman, circulating tumor cells, tumor, tumor biopsy, and exosomes.
The methods of the present invention are suitable for diagnosing or prognosing a disease state and/or distinguishing a genotype or disease predisposition.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of cells or tissue based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 6-12 markers, 12-24 markers, 24-36 markers, 36-48 markers, 48-72 markers, 72-96 markers, or >96 markers. Each marker in a given set is selected by having any one or more of the following criteria: present, or above a cutoff level, in >50% of biological samples of the disease cells or tissue from individuals diagnosed with the disease state; absent, or below a cutoff level, in >95% of biological samples of the normal cells or tissue from individuals without the disease state; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with the disease state; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without the disease state; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with the disease state. At least 50% of the markers in a set each comprise one or more methylated or hydroxymethylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated or hydroxymethylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with the disease state. The biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells is obtained. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. Nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with the disease state if a minimum of 2 or 3 markers are present or above a cutoff level in a marker set comprising from 6-12 markers; or a minimum of 3, 4, or 5 markers are present or above a cutoff level in a marker set comprising from 12-24 markers; or a minimum of 3, 4, 5, or 6 markers are present or above a cutoff level in a marker set comprising from 24-36 markers; or a minimum of 4, 5, 6, 7, or 8 markers are present or above a cutoff level in a marker set comprising from 36-48 markers; or a minimum of 6, 7, 8, 9, 10, 11, or 12 markers are present or above a cutoff level in a marker set comprising from 48-72 markers, or a minimum of 7, 8, 9, 10, 11, 12 or 13 markers are present or above a cutoff level in a marker set comprising from 72-96 markers, or a minimum of 8, 9, 10, 11, 12, 13 or “n”/12 markers are present or above a cutoff level in a marker set comprising 96 to “n” markers, when “n”>168 markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a solid tissue cancer including colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma, breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma, lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma, prostate adenocarcinoma, invasive urothelial bladder cancer, liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 48-72 total cancer markers, 72-96 total cancer markers or 96 total cancer markers. On average greater than one quarter such markers in a given set cover each of the aforementioned major cancers being tested. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >50% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer, said method comprising. The method involves obtaining a biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carring out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 48-72 total cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 72-96 total cancer markers; or a minimum of 6 or “n”/18 markers are present or are above a cutoff level in a marker set comprising 96 to “n” total cancer markers, when “n”>96 total cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of and identifying the most likely specific tissue(s) of origin of a solid tissue cancer in the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprises from 36-48 group-specific cancer markers, 48-64 group-specific cancer markers or 64 group-specific cancer markers, wherein on average greater than one third such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >50% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >50% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 36-48 group-specific cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 48-64 group-specific cancer markers; or a minimum of 6 or “n”/12 markers are present or are above a cutoff level in a marker set comprising 64 to “n” group-specific cancer markers, when “n”>64 group-specific cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a gastrointestinal cancer including colorectal adenocarcinoma, stomach adenocarcinoma, or esophageal carcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 6-12 markers, 12-18 markers, 18-24 markers, 24-36 markers, 36-48 markers or 48 markers. Each marker is selected by having any one or more of the following criteria for gastrointestinal cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with gastrointestinal cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without gastrointestinal cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with gastrointestinal cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without gastrointestinal cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with gastrointestinal cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with gastrointestinal cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with gastrointestinal cancer if a minimum of 2, 3 or 4 markers are present or are above a cutoff level in a marker set comprising from 6-12 markers; or a minimum of 2, 3, 4, or 5 markers are present or are above a cutoff level in a marker set comprising from 12-18 markers; or a minimum of 3, 4, 5, or 6 markers are present or are above a cutoff level in a marker set comprising from 18-24 markers; or a minimum of 3, 4, 5, 6, 7, or 8 markers are present or are above a cutoff level in a marker set comprising from 24-36 markers; or a minimum of 4, 5, 6, 7, 8, 9, or 10 markers are present or are above a cutoff level in a marker set comprising from 36-48 markers; or a minimum of 5, 6, 7, 8, 9, 10, 11, 12, or “n”/12 markers are present or are above a cutoff level in a marker set comprising 48 to “n” markers, when “n”>48 markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of a solid tissue cancer including colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma, breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma, lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma, prostate adenocarcinoma, invasive urothelial bladder cancer, liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma, based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 36-48 total cancer markers, 48-64 total cancer markers, or 64 total cancer markers, wherein on average greater than half of such markers in a given set cover each of the aforementioned major cancers being tested. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 36-48 total cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 48-64 total cancer markers; or a minimum of 6 or “n”/12 markers are present or are above a cutoff level in a marker set comprising 64 to “n” total cancer markers, when “n”>64 total cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state of and identifying the most likely specific tissue(s) of origin of a solid tissue cancer in the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or 48 group-specific cancer markers. On average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals are diagnosed or prognosed with a solid-tissue cancer if a minimum of 4 markers are present or are above a cutoff level in a marker set comprising from 24-36 group-specific cancer markers; or a minimum of 5 markers are present or are above a cutoff level in a marker set comprising from 36-48 group-specific cancer markers; or a minimum of 6 or “n”/8 markers are present or are above a cutoff level in a marker set comprising 48 to “n” group-specific cancer markers, when “n”>48 group-specific cancer markers.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state to guide and monitor treatment of a solid tissue cancer in one or more of the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or 48 group-specific cancer markers, wherein on average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals with a given tissue-specific cancer will on average have from approximately one-quarter to about one-half or more of the markers scored as present, or are above a cutoff level in the tested marker set, wherein to guide and monitor subsequent treatment, a portion or all of the identified markers scored as present or the identified markers scored as above a cutoff level in the tested marker set are deemed the “patient-specific marker set”, and retested on a subsequent biological sample from the individual during the treatment protocol, to monitor for loss of marker signal, wherein if a minimum of 3 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 12-24 markers; or if a minimum of 4 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 24-36 markers; or a minimum of 5 markers remain present or remain above a cutoff level in a patient-specific marker set comprising from 36-48 markers; or a minimum of 6 or “n”/8 markers remain present or remain above a cutoff level in a patient-specific marker set comprising 48 to “n” markers, when “n”>48 markers after the treatment protocol has been administered, then the continuing presence of said markers may guide a decision to change the cancer treatment therapy.
Another aspect of the present application is directed to a method of diagnosing or prognosing a disease state to monitor for recurrence of a solid tissue cancer in one or more of the following groups: Group 1 (colorectal adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma); Group 2 (breast lobular and ductal carcinoma, uterine corpus endometrial carcinoma, ovarian serous cystadenocarcinoma, cervical squamous cell carcinoma and adenocarcinoma, uterine carcinosarcoma); Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, head & neck squamous cell carcinoma); Group 4 (prostate adenocarcinoma, invasive urothelial bladder cancer); and/or Group 5 (liver hepatoceullular carcinoma, pancreatic ductal adenocarcinoma, or gallbladder adenocarcinoma) based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual, wherein the plurality of markers is in a set comprising from 24-36 group-specific cancer markers, 36-48 group-specific cancer markers, or 48 group-specific cancer markers, wherein on average greater than one half of such markers in a given set cover each of the aforementioned cancers being tested within that group. Each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >75% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >75% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer. At least 50% of the markers in a set each comprise of one or more methylated residues, and/or at least 50% of the markers in a set that are present, or above a cutoff level, or present with a z-value of >1.65 comprise of one or more methylated residues, in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from at least 50% of individuals diagnosed with a given solid tissue cancer. The method involves obtaining the biological sample, the biological sample including cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells, wherein the biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. The sample is fractionated into one or more fractions, wherein at least one fraction comprises exosomes, tumor-associated vesicles, other protected states, or cell-free DNA, RNA, and/or protein. The nucleic acid molecules in one or more fractions are subjected to a treatment with one or more DNA repair enzymes and chemicals under conditions suitable to convert methylated and hydroxymethylated cytosine residues to dihydrouracil residues. At least one enrichment step is carried out for 50% or more disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers during either said fractionating step and/or by carrying out a nucleic acid amplification step. The method further involves performing one or more assays to detect and distinguish the plurality of cancer-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers, thereby identifying their presence or levels in the sample, wherein individuals with a given tissue-specific cancer will on average have from one-quarter to about one-half or more of the markers scored as present, or are above a cutoff level in the tested marker set, wherein to monitor for recurrence, a portion or all of the markers scored as being present, or the markers scored as above a cutoff level in the tested marker set are deemed the “patient-specific marker set”, and retested on subsequent biological samples from the individual after a successful treatment, to monitor for gain of marker signal, wherein if a minimum of 3 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 12-24 markers; or if a minimum of 4 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 24-36 markers; or a minimum of 5 markers reappear or rise above a cutoff level in a patient-specific marker set comprising from 36-48 markers; or a minimum of 6 or “n”/8 markers reappear or rise above a cutoff level in a patient-specific marker set comprising 48 to “n” markers, when “n”>48 markers after the treatment protocol has been administered, then the reappearance or rise or rise above a cutoff level in a patient-specific marker set may guide a decision to resume the cancer treatment therapy or change to a new cancer treatment therapy.
In one embodiment, each marker in a given set for a given solid tissue cancer is selected by having any one or more of the following criteria for that solid tissue cancer: present, or above a cutoff level, in >66% of biological samples of a given cancer tissue from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples of the normal tissue from individuals without that given solid tissue cancer; present, or above a cutoff level, in >66% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer; absent, or below a cutoff level, in >95% of biological samples comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals without that given solid tissue cancer; present with a z-value of >1.65 in the biological sample comprising cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, bodily excretions, or fractions thereof, from individuals diagnosed with a given solid tissue cancer.
In certain embodiments, the at least one enrichment step comprises one or more of the following steps: capturing or separating exosomes or extracellular vesicles or markers in other protected states; capturing or separating a platelet fraction; capturing or separating circulating tumor cells; capturing or separating RNA-containing complexes; capturing or separating cfDNA-nucleosome or differentially modified cfDNA-histone complexes; capturing or separating protein targets or protein target complexes; capturing or separating auto-antibodies; capturing or separating cytokines; capturing or separating methylated or hydroxymethylated cfDNA; capturing or separating marker specific DNA, cDNA, miRNA, lncRNA, ncRNA, or mRNA, or amplified complements, by hybridization to complementary capture probes in solution, on magnetic beads, or on a microarray; amplifying miRNA markers, non-coding RNA markers (lncRNA & ncRNA markers), mRNA markers, exon markers, splice-variant markers, translocation markers, or copy number variation markers in a linear or exponential manner via a polymerase extension reaction, polymerase chain reaction, DNA repair enzyme and chemically-treated-methyl-specific polymerase chain reaction, reverse-transcription reaction, DNA repair enzyme and chemically-treated-methyl-specific ligation reaction, and/or ligation reaction, using DNA polymerase, reverse transcriptase, DNA ligase, RNA ligase, DNA repair enzyme, RNase, RNaseH2, endonuclease, restriction endonuclease, exonuclease, CRISPR, DNA glycosylase or combinations thereof; selectively amplifying one or more target regions containing mutation markers or DNA repair enzyme and chemically-treated-converted DNA methylation markers, while suppressing amplification of the target regions containing wild-type sequence or complement sequence thereof, in a linear or exponential manner via a polymerase extension reaction, polymerase chain reaction, DNA repair enzyme and chemically-treated-methyl-specific polymerase chain reaction, reverse-transcription reaction, DNA repair enzyme and chemically-treated-methyl-specific ligation reaction, and/or ligation reaction, using DNA polymerase, reverse transcriptase, DNA ligase, RNA ligase, DNA repair enzyme, RNase, RNaseH2, endonuclease, restriction endonuclease, exonuclease, CRISPR, DNA glycosylase or combinations thereof; preferentially extending, ligating, or amplifying one or more primers or probes whose 3′-OH end has been liberated in an enzyme and sequence-dependent process; using one or more blocking oligonucleotide primers comprising one or more mismatched bases at the 3′ end or comprising one or more nucleotide analogs and a blocking group at the 3′ end under conditions that interfere with polymerase extension or ligation during said reaction of target-specific primer or probes hybridized in a base-specific manner to wild-type sequence or complement sequence thereof.
Another aspect of the present application relates to a two-step method of diagnosing or prognosing a disease state of cells or tissue based on identifying the presence or level of a plurality of disease-specific and/or cell/tissue-specific DNA, RNA, and/or protein markers in a biological sample of an individual. The method involves obtaining a biological sample that includes exosomes, tumor-associated vesicles, markers within other protected states, cell-free DNA, RNA, and/or protein originating from the cells or tissue and from one or more other tissues or cells. The biological sample is selected from the group consisting of cells, serum, blood, plasma, amniotic fluid, sputum, urine, bodily fluids, bodily secretions, and bodily excretions, or fractions thereof. A first step is applied to the biological samples with an overall sensitivity of >80% and an overall specificity of >90% or an overall Z-score of >1.28 to identify individuals more likely to be diagnosed or prognosed with the disease state. A second step is then applied to biological samples from those individuals identified in the first step with an overall specificity of >95% or an overall Z-score of >1.65 to diagnose or prognose individuals with the disease state. The first step and/or the second step are carried out using a method of the present application.
Fluorescent labeling. Consider an instrument that can detect 5 fluorescent signals, F1, F2, F3, F4, and F5, respectively. As an example, in the case of colon cancer, the highest frequency mutations will be found for K-ras, p53, APC and BRAF. Mutations in these four genes could be detected with a single fluorescent signal; F1, F2, F3, F4. If the scale is 1000 FU, then primer would be added using ratios of labeled and unlabeled UniTaq primers, such that amplification of LDR products on mutant target of these genes yields about 300 FU at the plateau. For the controls, the F5 would be calibrated to give a signal of 100 FU for a 1:1,000 dilution quantification control, and an additional 300 FU for ligation of mutant probe on wild-type control (should give no or low background signal).
For the other genes commonly mutated in colon cancer as shown below, (or even lower abundance mutations in the p53 gene,) the following coding system may be used: Two fluorescent signals in equimolar amount at the 5′ end of the same UniTaq, with unlabeled primer titrated in, such that both fluorescent signals plateau at 100 FU. If fluorescent signals are F1, F2, F3, F4, then that gives the ability to detect mutations in 4 genes using a single fluorescent signal, and in mutations in 6 genes using combinations of fluorescent signal:
Gene 1=F1 (300 FU) (p53, Hot Spots)
Gene 8=F2 (100 FU), F3 (100 FU) (p53, additional)
Suppose there is a second mutation, combined with a mutation in one of the top genes. This is easy to distinguish, since the top gene will always give more signal, independent if it is overlapping with the other fluorescent signals or not. For example, if the fluorescent signal is F1 100 FU, and F2 400 FU, that would correspond to mutations in Gene 2 and Gene 5.
If there are two mutations from the less commonly mutated genes (Gene 5-Gene 10) then the results will appear either as an overlap in fluorescent signals, i.e. F1 200 FU, F2 100 FU, F4 100 FU, or all 4 fluorescent signals. If the fluorescent signals are in the ratio of 2:1:1, then it is rather straightforward to figure out the 2 mutations: in the above example, F1 200 FU, F2 100 FU, F4 100 FU, would correspond to mutations in Gene 5 and Gene 7. A similar approach for multiplexing different colors has been described by the Kartalov group (Rajagopal et al., “Supercolor Coding Methods for Large-Scale Multiplexing of Biochemical Assays,” Anal. Chem. 85(16):7629-36 (2013); U.S. Patent Application Publication No. 20140213471A1, which are hereby incorporated by reference in their entirety).
More recently, digital droplet PCR (ddPCR) has been used to provide accurate quantification of the number of mutant or methylated or hydroxymethylated molecules in a clinical sample. In general, amplification in a droplet implies at least a single molecule of the target was present in that droplet. Thus, when using a sufficient number of droplets that way exceed the number of initial targets, it is assumed that a given droplet only had a single molecule of the target. Thus, end-point PCR is often used to monitor the number of products.
Consider an instrument that can detect 5 fluorescent signals, F1, F2, F3, F4, and F5, respectively. Methylation in the promoter region of some genes often methylated in colon cancer could be used for the first four channels, for example F1=VIM, F2=SEPT9, F3=CLIP4, and F4=GSG1L. The last channel, F5 would be used as a control to assure a given droplet contained proper reagents, etc. Once again, combinations of fluorescent signal may be used to simultaneously detect methylation at 10 different promoter regions.
For simplicity, consider how ddPCR may be used to accurately enumerate the number of original methylated or hydroxymethylated molecules at 4 promoter regions using exPCR-ddPCR (see for example,
For distinguishing and enumerating 10 methylation markers simultaneously in a single ddPCR reaction, consider a total of 50 methylated or hydroxymethylated regions are being detected, with 10 promoter regions in a single ddPCR reaction comprising 10,000 droplets or micro-pores or micro-wells. Consider a sample with 2, 4, 5, 1, 0, 1, 3, 2, 0, and 1 molecule(s) of methylated promoter regions for VIM, SEPT9, CLIP4, GSG1L, PP1R16B, KCNA3, GDF6, ZNF677, CCNA1, and STK32B, respectively. Assume the initial one-sided primer extension with blocking primer has an efficiency of 50%, so after 20 cycles, there are=20; 40; 50; 10; 0; 10; 30; 20; 0; and 10 extension products of methylated promoter regions for VIM, SEPT9, CLIP4, GSG1L, PP1R16B, KCNA3, GDF6, ZNF677, CCNA1, and STK32B, respectively.
Also, with blocking primer for the top strand, again, assuming a general efficiency of 50%, after 6 cycles of PCR, there are (1.5 to the 6th=11×number of initial extension products)=220; 440; 550; 110; 0; 110; 330; 220; 0; and 110 copies of the PCR products for methylated VIM, SEPT9, CLIP4, GSG1L, PP1R16B, KCNA3, GDF6, ZNF677, CCNA1, and STK32B, respectively. When such products are then diluted into 5 ddPCR reactions, on average, a given chamber will comprise of 44; 88; 110; 22; 0; 22; 66; 44; 0; and 22 copies of the PCR products for methylated VIM, SEPT9, CLIP4, GSG1L, PP1R16B, KCNA3, GDF6, ZNF677, CCNA1, and STK32B, respectively. This is a total of about 418 of molecules that would be amplified with primers for the total PCR products for methylated VIM, SEPT9, CLIP4, GSG1L, PP1R16B, KCNA3, GDF6, ZNF677, CCNA1, and STK32B. If the ddPCR comprises 10,000 droplets or micro-pores or micro-wells, on average, only 1 in 25 will actually comprise a PCR reaction; the chances of a given droplet having two amplicons that would compete with each other for resources would be about 1 in 625, or about 16 droplets would comprise 2 amplicons, which would be only 4% of the total number of droplets with only a single amplicon. Since there are 45 combinations of 2 different amplicons, on average, less than 0.1% of the droplets would contain a given two amplicons. In other words, the rare droplet comprising 2 or 3 or 4 colors would not need to be de-convoluted, they could simply be ignored as they represent one or two droplets compared to about 22 droplets arising from a single molecule in the original sample. While it may be a bit difficult to distinguish 88 from 110 droplets, i.e. starting with 4 or 5 molecules of a given methylated or hydroxymethylated target, it should be relatively straightforward to distinguish 44, 88, and 22 copies, corresponding to 2, 4, and 1 target molecules in the original sample.
The above approach would also work for accurately enumerating mRNA, miRNA, ncRNA or lncRNA target molecules. The sample is used directly for subsequent ddPCR enumeration. For distinguishing and enumerating 10 mRNA, ncRNA, or lncRNA markers simultaneously in a single ddPCR reaction, consider a total of 50 mRNA, ncRNA or lncRNA regions are being detected in a single ddPCR reaction comprising 10,000 droplets or micro-pores or micro-wells. Once again, combinations of fluorescent signal may be used to simultaneously detect 10 mRNA or ncRNA markers.
Gene 1=F1 (mRNA1)
Gene 2=F2 (mRNA2)
Gene 3=F3 (mRNA3)
Gene 4=F4 (mRNA4)
Gene 5=F1+F2 (ncRNA5)
Gene 6=F1+F3 (ncRNA6)
Gene 7=F1+F4 (ncRNA7)
Gene 8=F2+F3 (ncRNA8)
Gene 9=F2+F4 (ncRNA9)
Gene 10=F3+F4 (ncRNA10)
Consider a sample with 2, 4, 15, 1, 0, 10, 3, 20, 0, and 1 molecule(s) of mRNA1-4 and ncRNA5-10, respectively. Six cycles of RT-PCR will generate 64 cDNA copies of each transcript generating=128; 256; 960; 64; 0; 640; 192; 1280; 0; and 64 copies of mRNA1-4 and ncRNA5-10, respectively. When such products are then diluted into 5 ddPCR reactions, on average, a given chamber will comprise of 25; 51; 192; 13; 0; 128; 28; 256; 0; and 13 copies of the PCR products for mRNA1-4 and ncRNA5-10, respectively. This is a total of about 706 of molecules that would be amplified with primers for the total PCR products for methylated mRNA1-4 and ncRNA5-10. If the ddPCR comprises 10,000 droplets or micro-pores or micro-wells, on average, only 1 in 14 will actually comprise a PCR reaction. The two most common RNA's in this example; mRNA 3 and ncRNA5 would be present on average of 1 in 52 and 1 in 39, thus the chances of a given droplet having these two amplicons that would compete with each other for resources would be about 1 in 2028, or about 5 droplets would comprise 2 amplicons, which is still less than for a single molecule after amplification—which will generate 13 copies. In other words, the rare droplet comprising 2 or 3 or 4 colors would not need to be de-convoluted, they could simply be ignored as they represent from 1 to 5 droplets compared to at least 13 droplets arising from a single molecule in the original sample. If some RNA molecules are present in higher amounts, one can still de-convolute multiple signals arising from 2 amplicons in a given droplet, using the same approach of different color probes at different levels of FU (i.e. 300 FU for products with a single color; 100 FU each for products using 2 colors) as articulated earlier.
Another aspect of the present application relates to the ability to distinguish cancer at the earliest stages when analyzing markers within a blood sample. The average body contains about 6 liters (6,000 ml) of blood. A 10 ml sample will then comprise 1/600th of the sample. While some cancers (i.e. lung cancer, melanoma) have a high mutational load, other cancers (i.e. breast, ovarian) have few mutations, and even fewer at the earliest stages. In contrast, methylation changes in promoter regions (i.e. methylation markers) appear to be early events. For the purposes of the calculations below, assume that if a marker is present in the sample, it can be detected down to the single molecule level, independent of the technology that is being used to identify the marker.
On a practical level, different cancers have different frequencies for different mutational markers. For example, the mutation rate for gene K-ras is ˜30% and >90% for colorectal cancer and pancreatic cancer, respectively. While p53 is found mutated in about 50% of all cancers, more often than not, such a mutation is manifested in late-stage tumors. As a benchmark, a given cancer during its earliest stage, generates at least one detectable mutation. Suppose that at any given time, there are 200 mutated molecules circulating in the plasma of the patient. Given the total volume, if there is a 10 ml sample, taken, then there is about a ⅓rd chance that the sample will contain at least 1 mutated molecule. A more accurate prediction would be based on the Poisson distribution. If there are 200 objects (i.e. mutated molecules) distributed into 600 bins (i.e. 600 aliquots of 10 ml representing the total blood volume of a patient), Poisson calculation would indicate that: 72% of wells will have 0 objects, 23.7% will have 1 object, 3.9% will have 2 objects, 0.4% will have 3 objects, etc. In other words, 28.1% of the aliquots would have at least one mutated molecule. If the assay is capable of detecting every single mutated molecule, then its sensitivity would be 28.1%. Likewise, if there were 300 objects (i.e. mutated molecules) distributed into 600 bins (i.e. 600 aliquots of 10 ml), then: 61% of wells will have 0 objects, 30.3% will have 1 object, 7.6% will have 2 objects, 1.3% will have 3 objects, etc. In other words, 39.4% of the aliquots would have at least one mutated molecule. If the assay is capable of detecting every single mutated molecule, its sensitivity is at 39.4%. Likewise, if there were 400 objects (i.e. mutated molecules) distributed into 600 bins (i.e. 600 aliquots of 10 ml), then: 51% of wells will have 0 objects, 34.3% will have 1 object, 11.5% will have 2 objects, 2.5% will have 3 objects, etc. In other words, 49% of the aliquots would have at least one mutated molecule. If the assay detects every single mutated molecule, its sensitivity would be 49%. Likewise, if there were 600 objects (i.e. mutated molecules) distributed into 600 bins (i.e. 600 aliquots of 10 ml), then the Poisson calculation would be: 36.8% of wells will have 0 objects, 36.8% will have 1 object, 18.3% will have 2 objects, 6.1% will have 3 objects, etc. In other words, 63.2% of the aliquots would have at least one mutated molecule. If the assay detects every single mutated molecule, then its sensitivity will be 63.2%. Nevertheless, on a practical level, even with a detectable marker load as high as 600 molecules, the assay would still miss 36.8% of early cancers for that type of tumor. Recent literature results have argued what constitutes “early cancer”, with some groups claiming stage I & II cancers are early cancer, while others claiming that stages I, II, and III cancers are early cancer, both the definition and type varies, but general when scoring form mutations the results have reported sensitivities ranging from around 20% to around 70%—which translates into missing 30% to 80% of early cancers (Klein et al., “Development of a Comprehensive Cell-free DNA (cfDNA) Assay for Early Detection of Multiple Tumor Types: The Circulating Cell-free Genome Atlas (CCGA) Study,” Journal of Clinical Oncology 36(15):12021-12021 (2018); Liu et al., “Breast Cancer Cell-free DNA (cfDNA) Profiles Reflect Underlying Tumor Biology: The Circulating Cell-free Genome Atlas (CCGA) Study,” Journal of Clinical Oncology 36(15):536-536 (2018), which are hereby incorporated by reference in their entirety).
The above calculations are performed based on the assumption that detecting even a single mutation is sufficient to call a patient positive. Initial work identifying mutations in the blood from patients with metastatic disease revealed an average of 5 mutations not only in the patients, but also in age-matched controls (Razavi, et al., “Cell-free DNA (cfDNA) Mutations From Clonal Hematopoiesis: Implications for Interpretation of Liquid Biopsy Tests,” Journal of Clinical Oncology 35(15):11526-11526 (2017), which is hereby incorporated by reference in its entirety). This phenomenon, known as clonal hematopoiesis, results from accumulation of mutations in white-blood cells, that then undergo clonal expansion. Once the presence of such mutations are accounted for (by sequencing an aliquot of WBC DNA from the same individual), the accuracy or specificity of these tests has been set at 98%. For some cancers like ovarian cancer, which exhibit low mutation load, an estimated 60% of the disease at its early stage would be missed. To put these number in perspective, there were 20,240 new cases of ovarian cancer in the US in 2018. Thus, about 55 million women (over the age of 50) should be tested for the disease. Such test would identify 8,096 women with ovarian cancer. However, there would be about 1.1 million false-positives. The positive predictive value of such a test would be around 0.74%. In other words, only one in 136 women who tested positive would actually have ovarian cancer, the rest would be false-positives.
For a multi-marker test of the present application, two or more markers need to be deemed positive in order the overall screening result to be deemed positive. By increasing the total number of individual markers used, as well as the number of markers required to call the overall screening test positive, both sensitivity and specificity for detecting early cancer may be improved. The overall early cancer detection sensitivity is a function of the average number of each marker in the blood, the average number of markers positive, the minimum number of markers required to call the sample positive, and the total number of markers scored. For example, if the test uses 12 methylation markers, that on average are methylated (or hydroxymethylated) in >50% of tumors for that cancer type, then on average, about 6 markers will be methylated for a given sample. If on average there are 600 methylated molecules in the blood for each marker, then on average a total of 600×600=3,600 objects (i.e. methylated molecules) are distributed into 600 bins (i.e. 600 aliquots of 10 ml). As an approximate calculation based on the Poisson calculation, the distribution would be: 0.2% of wells will have 0 objects, 1.5% will have 1 object, 4.5% will have 2 objects, 8.9% will have 3 objects, 13.3% will have 4 objects, 16.0% will have 5 objects, 16.0% will have 6 objects, 13.8% will have 7 objects, 10.3% will have 8 objects etc. Suppose that at least two markers need to be called positive. In this case, 1.7% (=0.2%+1.5%) of the aliquots with either 0 or 1 object (i.e. methylation markers) would be called negative. Thus, if a minimum of two markers are required to call the sample positive, then the sensitivity of the assay would be 100%−1.7%=98.3% sensitivity. Suppose that at least three markers need to be called positive. In this case, aliquots with either 0, 1 or 2 objects (i.e. methylation markers) would be called negative=0.2%+1.5%+4.5%=6.2%. Thus, if a minimum of two markers are required to call the sample positive, then the sensitivity of the assay would be 100%−6.2%=93.8% sensitivity. It is understood that a small fraction of aliquots with 3 markers positive will contain 2 molecules of one marker, and one molecule of a second marker, and thus not contain the minimum of three different markers positive, nevertheless, this is a small deviation from the approximate calculation above.
The overall early cancer detection specificity is a function of the average number of markers positive, the false-positive rate for each individual marker, the minimum number of markers required to call the sample positive, and the total number of markers scored. To estimate the overall false-positive rate, a formula is used based on the probability of binning different color socks into a number of drawers. Consider the percentage of false positives for each marker=“% FP”; the total number of markers “m”, and the minimum number of markers required to call the sample positive “n”. Then the formula for calculating overall false positive would be: (% FP)n×[m!/(m−n)!n!]. Suppose that percentage of false positives for each marker=“% FP” is at 4%; the total number of markers “m” is 12, and the minimum number of markers required to call the sample positive “n” is 3. Then the above formula for overall false-positives would be (4%)3×[12!/9!3!]=(4%)3×[12×11×10/6]=1.4%. Thus, the overall specificity would be [100%−1.4%]=98.6%. The actual individual false-positive rate may differ for different markers. Further, it may depend on the source of the false-positive signal. If for example, age-related methylation is due to clonal hematopoiesis, i.e. results from accumulation of methylations in white-blood cells, that then undergo clonal expansion. This type of false-positive may be mitigated by also scoring for methylation changes in white blood cells from the same patient. On the other hand, if the source of the false-positive signal is due to release of DNA into the plasma due to tissue inflammation, or for example breakdown of muscle tissue from weight-lifting, then mitigating that signal may require sampling the blood at a different time when the body is rested, or a month later when inflammation has subsided.
From the above tables, the receiver operating characteristic (ROC) curves may be calculated by plotting Sensitivity vs. 1-Specificity. Since these are theoretical calculations, the curves were generated for different levels of average marker false-positive rates of 2%, 3%, 4%, and 5%. To assist in visualizing the graphs and calculating the AUC (Area under curve), the edges were set at 100% and 0%, respectively. The ROC curves for 24 marker, 3% & 4% average marker false-positives, 36 marker, 3% & 4% average marker false-positives, and 48 marker, 2%, 3%, 4% & 5% average marker false-positives are provided in Table 13 below and for 48 Markers illustrated in
How would the above markers work in a one-step cancer assay? To illustrate the challenges of developing an early cancer detection screen, consider the challenge of screening 107 million adults in the U.S. over the age of 50 for colorectal cancer—of which there are about 135,000 new cases that are diagnosed a year. In this example, if there is an average of 300 molecules in the blood for early cancer (Stage I & II), and taking the best-case scenario of individual marker FP rate is 2%, then if there is a 3-marker minimum, then overall FP rate is 1.6% for 24 markers, for a specificity of 98.4% (See
However, if the individual marker FP rate is more realistic, say 4%, then more markers will be required to achieve better than 98% specificity, and this will be at the cost of sensitivity. If individual marker FP rate is 4%, then if there is a 5-marker minimum, then overall FP rate is 0.4% for 24 markers, for a specificity of 99.6% (See
The first step and the second step are carried out using a method of the present application. The first step uses markers to cover many cancers, where the aim is to obtain high sensitivity for early cancers where the number of marker molecules in the blood may be limited. The second step then would score for additional markers to verify that the initial result was a true positive, as well as to identify the likely tissue of origin. The second step may include the methods described herein, and/or additional methods such as next-generation sequencing.
To illustrate one embodiment of how such a two-step cancer test may be designed, consider again the challenge of identifying patients with early colorectal cancer. In 2017, there were an estimated 95,520 new cases of colon cancer and 39,910 cases of rectal cancer diagnosed in the U.S.—for a total of about 135,000 new cases. Consider an initial test using 24 markers. In this example, if there is an average of 300 molecules in the blood for early cancer (Stage I & II), and if that would cover at least one mutation, then the sensitivity for identifying such a cancer by next generation sequencing would be 39.4% (See
By using a two-step cancer test, the parameters may be adjusted to improve BOTH sensitivity and specificity. For example, the aforementioned 24 marker test, using 3 markers, for Stage I & II cancer (at about 300 molecules of each positive marker in the blood), the overall sensitivity would be 93.8%. Those samples that are scored as positives in the first step (24-markers specific to GI cancers)—including the false-positives would be retested in the second step with an expanded panel of 48 markers to provide coverage of colorectal cancers. If the individual marker FP rate is 3%, then if there is a 5-marker minimum, then overall FP rate is 4.2% for 48 markers, for a specificity of 95.8% (See
Returning to the example of colorectal cancer, in particular the cases of microsatellite stable tumors (MSS) where the mutation load is low, for these calculations when relying on NGS sequencing alone (assuming 300 molecules with one mutation in the blood), an estimated 60% of early colorectal cancer would be missed. Again, to put these number in perspective, in the U.S., about 135,000 new cases of colorectal cancer are predicted in 2018. About 107 million individuals in the U.S. are over the age of 50 and should be tested for colorectal cancer. With the assumption of these samples containing at least 300 molecules with one mutation in the blood, such a test would find 54,000 men and women (out of 135,000 new cases) with colorectal cancer. However, with a specificity for sequencing at 98%, there would be about 2.1 million false-positives. The positive predictive value of such a test would be around 2.6%, in other words, only one in 39 individuals who tested positive would actually have colorectal cancer, the rest would be false-positives. In contrast, consider the two-step methylation marker test described above, wherein the first step has 24 methylation markers specific to GI cancers, while the second step has 48 methylation markers specific to colorectal cancer. In this example, as above, the calculations are done with the anticipation of an average of 300 methylated (or hydroxymethylated) molecules per positive marker in the blood. Assuming individual marker false-positive rates of 3%, and with the first step requiring a minimum of 3 markers positive, then with an overall specificity of 94.6%, the first step would identify 5,778,000 individuals (out of 107,000,000 total adults over 50 in the U.S.) which would include at 93.8% sensitivity about 126,630 individuals with Stage I & II colorectal cancer (out of 135,000 total). However, those 5,778,000 presumptive positive individuals would be evaluated in the second step of 48 markers requiring a minimum of 6 markers positive, then the two-step test would identify 98.1%×93.8%=92.0%=124,200 individuals (out of 135,000 new cases) with colorectal cancer. With a specificity of 99.1%, the second test would also generate 5,778,000×0.9%=52,000 false-positives. The positive predictive value of such a test would be 124,200/176,200=70.5%, in other words, 2 in 3 individuals who tested positive would actually have colorectal cancer, an extraordinarily successful screen to focus on those patients who would most benefit from follow-up colonoscopy. The benefit in lives saved would be of incalculable value.
While the foregoing discussion has focused on methylation markers, with an average sensitivity of 50%, and individual marker false-positives ranging from 2%-5%, there are many other markers of cancer with varying sensitivities and specificities. In general, protein markers (with the exception of PSA and PSMA) have been of limited clinical utility for detection of early cancer because the false-positives are so high, resulting in very low positive predictive value. Cancer markers from bodily fluids (i.e. plasma, urine) include, but are not limited to plasma microRNAs (miRNA); mutations or methylation in cfDNA; exosomes with surface cancer-specific protein markers, or internal miRNA, ncRNA, lncRNA, mRNA, DNA; circulating cytokines, circulating proteins, or circulating antibodies against cancer-antigens; or nucleic-acid markers in whole blood (for review, see Nikolaou et al., “Systematic Review of Blood Diagnostic Markers in Colorectal Cancer,” Techniques in Coloproctology (2018), which is hereby incorporated by reference in its entirety). Several methods have been reported for detecting cancer-specific miRNAs in the serum or plasma of patients with colorectal (or others) cancers; these miRNAs include, but are not limited to: miR-1290; miR-21; miR-24; miR-320a; miR-423-5p; miR-29a; miR-125b; miR-17-3p; miR-92a; miR-19a; miR-19b; miR-15b; mir23a; miR-150; miR-223; miR-1229; miR-1246; miR-612; miR-1296; miR-933; miR-937; miR-1207; miR-31; miR-141; miR-224-3p; miR-576-5p; miR-885-5p; miR-200c; miR-203 (Imaoka et al., “Circulating MicroRNA-1290 as a Novel Diagnostic and Prognostic Biomarker in Human Colorectal Cancer,” Ann. Oncol. 27(10):1879-1886 (2016); Zhang et al., “Diagnostic and Prognostic Value of MicroRNA-21 in Colorectal Cancer: an Original Study and Individual Participant Data Meta-Analysis,” Cancer Epidemiol. Biomark. Prev. 23(12):2783-2792 (2016); Fang et al., “Plasma Levels of MicroRNA-24, MicroRNA-320a, and Micro-RNA-423-5p are Potential Biomarkers for Colorectal Carcinoma,” J. Exp. Clin. Cancer Res. 34:86 (2015); Toiyama et al., “MicroRNAs as Potential Liquid Biopsy Biomarkers in Colorectal Cancer: A Systematic Review,” Biochim. Biophys. Acta. pii: 50304-419X(18)30067-2 (2018); Nagy et al., “Comparison of Circulating miRNAs Expression Alterations in Matched Tissue and Plasma Samples During Colorectal Cancer Progression,” Pathol. Oncol. Res. doi: 10.1007/s12253-017-0308-1 (2017); Wang et al., “Novel Circulating MicroRNAs Expression Profile in Colon Cancer: a Pilot Study,” Eur. J. Med. Res. 22(1):51 (2017); U.S. Pat. No. 9,689,036 to Getts et at; U.S. Pat. No. 9,708,643 to Duttagupta et al.; U.S. Pat. No. 9,868,992 to God et al; U.S. Pat. No. 9,926,603 to Sozzi et al., which are hereby incorporated by reference in their entirety). Additional approaches for detecting low abundance miRNA are described in WO2016057832A2, which is hereby incorporated by reference in its entirety, or using other suitable means known in the art.
Several methods have been reported for detecting cancer-specific ncRNA or lncRNAs in the serum, plasma, or exosomes of patients with colorectal (and other) cancers; these ncRNAs include, but are not limited to: NEAT_v1; NEAT_v2; CCAT1; HOTAIR; CRNDE-h; H19; MALAT1; 91H; GASS (Wu et al., “Nuclear-enriched Abundant Transcript 1 as a Diagnostic and Prognostic Biomarker in Colorectal Cancer,” Mol. Cancer 14:191 (2015); Zhao et al., “Combined Identification of Long Non-Coding RNA CCAT1 and HOTAIR in Serum as an Effective Screening for Colorectal Carcinoma,” Int. J. Clin. Exp. Pathol. 8(11):14131-40 (2015); Liu et al., “Exosomal Long Noncoding RNA CRNDE-h as a Novel Serum-Based Biomarker for Diagnosis and Prognosis of Colorectal Cancer,” Oncotarget 7 (51):85551-85563 (2016); Slaby 0, “Non-coding RNAs as Biomarkers for Colorectal Cancer Screening and Early Detection,” Adv Exp Med Biol. 937:153-70 (2016); Gao et al., “Exosomal lncRNA 91H is Associated With Poor Development in Colorectal Cancer by Modifying HNRNPK Expression,” Cancer Cell Int. 23; 18:11 (2018); Liu et al., “Prognostic and Predictive Value of Long Non-Coding RNA GASS and MicroRNA-221 in Colorectal Cancer and Their Effects on Colorectal Cancer Cell Proliferation, Migration and Invasion,” Cancer Biomark. 22(2):283-299 (2018); U.S. Pat. No. 9,410,206 to Hoon et al.; U.S. Pat. No. 9,921,223 to Kalluri et al., which are hereby incorporated by reference in their entirety). Additional approaches for detecting low abundance lncRNA, ncRNA, mRNA translocations, splice variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicing, exon insertions, exon deletions, and intron insertions are described in WO2016057832A2, which is hereby incorporated by reference in its entirety, or using other suitable means known in the art.
The most common protein marker for colorectal cancer is based on detecting hemoglobin from blood in the stool and is known as the FOBT or FIT test. Sensitivity and specificities (Sens.: Spec.) for these tests have been reported as: OC-Light iFOB Test (also called OC Light S FIT), manufactured by Polymedco (78.6%-97.0%:88.0%-92.8%); QuickVue iFOB, manufactured by Quidel (91.9%:74.9%); Hemosure One-Step iFOB Test, manufactured by Hemosure, Inc. (54.5%:90.5%); InSure FIT, manufactured by ClinicalGenomics (75.0%:96.6%); Hemoccult-ICT, manufactured by Beckman Coulter (23.2%-81.8%: 95.8%-96.9%); Cologuard—stool FIT-DNA, manufactured by Exact Sciences (92.3%; 84.4%). The large ranges and differences in sensitivities and specificities may reflect the range from early to late cancer, as well as differences in methodology, number of samples collected, and clinical study size. Cut-off values for FIT tests may range from 10 ug protein/gram stool to 300 ug protein/gram stool (See Robertson et al., “Recommendations on Fecal Immunochemical Testing to Screen for Colorectal Neoplasia: a Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer,” Gastrointest. Endosc. 85(1):2-21 (2017), which is hereby incorporated by reference in its entirety).
A number of tumor-associated antigens elicit an immune response within the patient, and these may be identified as autoantibodies, or indirectly as increased cytokines in the serum. Some tumor antigens may be detected directly within the serum, or on the surface of cancer-associated exosomes or extracellular vesicles, while others may be detected indirectly, for example by an increase in mRNA within cancer-associated exosomes or extracellular vesicles. These cancer-specific protein markers may be identified through, mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product, and these markers include but are not limited to: RPH3AL; RPL36; SLP2; TP53; Survivin; ANAXA4; SEC61B; CCCAP; NYCO16; NMDAR; PLSCR1; HDAC5; MDM2; STOML2; SEC61-beta; IL8; TFF3; CA11-19; IGFBP2; DKK3; PKM2; DC-SIGN; DC-SIGNR; GDF-15; AREG; FasL; Flt3L; IMPDH2; MAGEA4; BAG4; IL6ST; VWF; EGFR; CD44; CEA; NSE; CA 19-9, CA 125; NMMT; PSA; proGRP; DPPIV/seprase complex; TFAP2A; E2F5; CLIC4; CLIC1; TPM1; TPM2; TPM3; TPM4; CTSD-30; PRDX-6; LRG1; TTR; CLU; KLKB1; C1R; KLK3; KLK2; HOXB13; GHRL2; FOXA1 (Fan et al., “Development of a Multiplexed Tumor-Associated Autoantibody-Based Blood Test for the Detection of Colorectal Cancer,” Clin. Chim. Acta. 475:157-163 (2017); Xia et al., “Prognostic Value, Clinicopathologic Features and Diagnostic Accuracy of Interleukin-8 in Colorectal Cancer: a Meta-Analysis,” PLoS One 10(4):e0123484 (2015); Li et al., “Serum Trefoil Factor 3 as a Protein Biomarker for the Diagnosis of Colorectal Cancer,” Technol. Cancer. Res. Treat. 16(4):440-445 (2017); Overholt et al., “CA11-19: a Tumor Marker for the Detection of Colorectal Cancer,” Gastrointest. Endosc. 83(3):545-551 (2016); Fung et al., “Blood-based Protein Biomarker Panel for the Detection of Colorectal Cancer,” PLoS One 10(3): e0120425 (2015); Jiang et al., “The Clinical Significance of DC-SIGN and DC-SIGNR, Which are Novel Markers Expressed in Human Colon Cancer,” PLoS One 9(12):e11474 (2014).; Chen et al., “Development and Validation of a Panel of Five Proteins as Blood Biomarkers for Early Detection of Colorectal Cancer,” Clin. Epidemiol. 9:517-526 (2017); Chen et al., “Prospective Evaluation of 64 Serum Autoantibodies as Biomarkers for Early Detection of Colorectal Cancer in a True Screening Setting,” Oncotarget 7(13):16420-32 (2016); Rho et al., “Protein and Glycomic Plasma Markers for Early Detection of Adenoma and Colon Cancer,” Gut 67(3):473-484 (2018); U.S. Pat. No. 9,518,990 to Wild et al.; U.S. Pat. No. 9,835,636 to Chan et al.; U.S. Pat. No. 9,885,718 to Man et al.; U.S. Pat. No. 9,889,135 to Andy Koff et al.; U.S. Pat. No. 9,903,870 to Speicher et at; U.S. Pat. No. 9,914,974 to Bajic et al.; U.S. Pat. No. 9,983,208 to Choi et al; U.S. Pat. No. 10,030,271 to Scher et al., which are hereby incorporated by reference in their entirety). Additional approaches for detecting low abundance mRNA translocations, splice variants, alternative transcripts, alternative start sites, alternative coding sequences, alternative non-coding sequences, alternative splicing, exon insertions, exon deletions and intron insertions are described in WO2016057832A2, which is hereby incorporated by references in its entirety, or using other suitable means known in the art.
The distribution of mutations in colorectal cancers are available in the public COSMIC database, with the 20 most commonly altered genes listed as: APC; TP53; KRAS; FAT4; LRP1B; PIK3CA; TGFBR2; ACVR2A; BRAF; ZFHX3; KMT2C; KMT2D; FBXW7; SMAD4; ARID1A; TRRAP; RNF43: FAT1; TCF7L2; PREX2 (Forbes et al., “COSMIC: Exploring the World's Knowledge of Somatic Mutations in Human Cancer,” Nucleic Acids Res. 43(Database issue):D805-811 (2015), which is hereby incorporated by reference in its entirety). Analysis of TCGA COADREAD mutational dataset, however indicate the following genes have at least 10% mutation rate among colorectal cancer primary tumors: APC, TP53, KRAS, TTN, SYNE1, PIK3CA, FAT4, MUC16, FBXW7, LRP1B, LRP2, DNAH5, DMD, ANK2, RYR2, FLG, HMCN1, FAT2, TCF7L2, CSMD3, USH2A, SDK1, CSMD1, COL6A3, DNAH2, SMAD4, PKHD1, FAM123B, ATM, ACVR2A, MDN1, DCHS2, ZFHX4, CUBN, CSMD2, FREM2, RYR1, TGFBR2, RYR3, SACS, DNAH10, ABCA12, BRAF, ODZ1, PCDH9, MACF1, and AHNAK2. In addition to the approaches described herein, there are several approaches for enriching for and detecting low-abundance mutations either at the DNA or mRNA level (for example, mRNA within exosomes), including but not limited to next generation sequencing, allele-specific PCR, ARMS, primer-extension PCR, using blocking primers, full-COLD-PCR, fast-COLD-PCR, ice-COLD-PCR, E-ice-COLD-PCR, TT-COLD-PCR, etc. (Mauger et al., “COLD-PCR Technologies in the Area of Personalized Medicine: Methodology and Applications,” Mol. Diagn Ther. 3:269-283 (2017); Sefrioui et al., “Comparison of the Quantification of KRAS Mutations by Digital PCR and E-ice-COLD-PCR in Circulating-Cell-Free DNA From Metastatic Colorectal Cancer Patients,” Clin. Chim. Acta. 465:1-4 (2017); U.S. Pat. No. 9,062,350 to Platica; U.S. Pat. No. 9,598,735 to Song et al., which are hereby incorporated by reference in their entirety). Additional approaches for detecting low abundance mutations are described in WO2016057832A2, which is hereby incorporated by reference in its entirety, or using other suitable means known in the art. Methods to detect mutations, insertions, deletions, expression changes, copy number changes splice variants, translocations, mRNA, lncRNA, ncRNA, and miRNA using exPCR-LDR-qPCR and related techniques are described in the concurrently submitted PCT application entitled “Method and Markers for Identifying and Relative Quantifying of Nucleic Acid Sequence, Mutation, Expression, Splice Variant, Translocation, Copy Number, or Methylation Changes using Combinations of Bisulfite Treatment, Nuclease, Ligation, and Polymerase Reactions with Carryover Prevention” (Attorney Docket No. 147402.08281), which claims benefit of U.S. Provisional Patent Application Ser. No. 62/843,032, filed May 3, 2019, both of which are hereby incorporated by reference in their entirety, or using other suitable means known in the art. The best studied blood-based methylation markers for CRC detection are located in the promoter region of the SEPT9 gene (Church et al., “Prospective Evaluation of Methylated SEPT9 in Plasma for Detection of Asymptomatic Colorectal Cancer,” Gut 63(2):317-325 (2014); Lofton-Day et al., “DNA Methylation Biomarkers for Blood-Based Colorectal Cancer Screening,” Clinical Chemistry 54(2):414-423 (2008); Potter et al., “Validation of a Real-time PCR-based Qualitative Assay for the Detection of Methylated SEPT9 DNA in Human Plasma,” Clinical Chemistry 60(9):1183-1191 (2014); Ravegnini et al., “Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker,” International Journal of Molecular Sciences 16(12):28486-28497 (2015); Toth et al., “Detection of Methylated SEPT9 in Plasma is a Reliable Screening Method for Both Left- and Right-sided Colon Cancers,” PloS One 7(9):e46000 (2012); Toth et al., “Detection of Methylated Septin 9 in Tissue and Plasma of Colorectal Patients With Neoplasia and the Relationship to the Amount of Circulating Cell-free DNA,” PloS One 9(12):e115415 (2014); Warren et al., “Septin 9 Methylated DNA is a Sensitive and Specific Blood Test for Colorectal Cancer,” BMC Medicine 9:133 (2011), which are hereby incorporated by reference in their entirety), and other potential markers for CRC diagnostics include CpG sites on promoter regions of THBD, C9orf50, ZNF154, AGBL4, FLI1, and TWIST1 (Lange et al., “Genome-scale Discovery of DNA-methylation Biomarkers for Blood-based Detection of Colorectal Cancer,” PloS One 7(11):e50266 (2012); Margolin et al., “Robust Detection of DNA Hypermethylation of ZNF154 as a Pan-Cancer Locus with in Silico Modeling for Blood-Based Diagnostic Development,” The Journal of Molecular Diagnostics: JMD 18(2):283-298 (2016); Lin et al., “Clinical Relevance of Plasma DNA Methylation in Colorectal Cancer Patients Identified by Using a Genome-Wide High-Resolution Array,” Ann. Surg. Oncol. 22 Suppl 3:S1419-1427 (2015), which are hereby incorporated by reference in their entirety).
SEPT9 methylation is the basis for Epi proColon test, a CRC-detection assay by Epigenomics (Lofton-Day et al:, “DNA Methylation Biomarkers for Blood-based Colorectal Cancer Screening,” Clinical Chemistry 54(2):414-423 (2008), which is hereby incorporated by reference in its entirety). While initial results on smaller sample sets showed promise, large-scale studies with 1,544 plasma samples showed a sensitivity of 64% for stage I-III CRC, and a specificity of 78%-82%, effectively sending 180 to 220 out of 1,000 individuals to unnecessary colonoscopies (Potter et al., “Validation of a Real-time PCR-based Qualitative Assay for the Detection of Methylated SEPT9 DNA in Human Plasma,” Clinical Chemistry 60(9):1183-1191 (2014), which is hereby incorporated by reference in its entirety). ClinicalGenomics is currently developing blood-based CRC detection test based on the methylation of the BCAT1 and IKZF1 genes (Pedersen et al., “Evaluation of an Assay for Methylated BCAT1 and IKZF1 in Plasma for Detection of Colorectal Neoplasia,” BMC Cancer 15:654 (2015), which is hereby incorporated by reference in its entirety). Large-scale studies using 2,105 plasma samples of this two-marker test showed an overall sensitivity of 66%, with 38% for stage I CRC, and an impressive specificity of 94%. Exact Sciences and collaborators have slightly improved the sensitivity of CRC fecal tests (Bosch et al., “Analytical Sensitivity and Stability of DNA Methylation Testing in Stool Samples for Colorectal Cancer Detection,” Cell Oncol. (Dordr) 35(4):309-315 (2012); Hong et al., “DNA Methylation Biomarkers of Stool and Blood for Early Detection of Colon Cancer,” Genet. Test. Mol. Biomarkers 17(5):401-406 (2013); Imperiale et al., “Multitarget Stool DNA Testing for Colorectal-Cancer Screening,” N. Engl. J. Med. 370(14):1287-1297 (2014); Xiao et al., “Validation of Methylation-Sensitive High-resolution Melting (MS-HRM) for the Detection of Stool DNA Methylation in Colorectal Neoplasms,” Clin. Chim. Acta. 431:154-163 (2014); Yang et al., “Diagnostic Value of Stool DNA Testing for Multiple Markers of Colorectal Cancer and Advanced Adenoma: a Meta-Analysis,” Can. J. Gastroenterol. 27(8):467-475 (2013), which are hereby incorporated by reference in their entirety), by adding K-ras mutation as well as BMP3 and NDRG4 methylation markers (Lidgard et al., “Clinical Performance of an Automated Stool DNA Assay for Detection of Colorectal Neoplasia,” Clin. Gastroenterol. Hepatol. 11(10):1313-1318 (2013), which is hereby incorporated by reference in its entirety). Epigenetic changes may mark not only the DNA (as methylation or hydroxy-methylation of promoter CpG sites) but also by appending methyl or acetyl groups on the histone proteins that bind to these promoters. These different epigenetic marks may be detected in circulating nucleosomes of colorectal cancer patients (Rahier et al., “Circulating Nucleosomes as New Blood-based Biomarkers for Detection of Colorectal Cancer,” Clin Epigenetics 9:53 (2017), which is hereby incorporated by reference in its entirety). The identification of blood-based, cancer-specific methylation markers has employed the entire TCGA Illumina 450K methylation datasets (consisting of primary tumors, matching normal for 33 types of cancer including CRC), along with additional methylation datasets (primary tumors, normal tissues, cell lines, peripheral blood, immune cells) from the Gene Expression Omnibus (GEO). In order to identify CRC-specific methylation markers, comparative statistical analyses of these datasets were used to identify candidate methylation markers with the following characteristics: highly methylated (or hydroxymethylated) in CRC tissues and cell lines, unmethylated in normal colon, unmethylated in peripheral blood and immune infiltrates, unmethylated in most other cancer types. Validating the bioinformatic scheme, these methodologies also identified CpG sites previously reported to be hypermethylated in plasma from CRC patients (Church et al., “Prospective Evaluation of Methylated SEPT9 in Plasma for Detection of Asymptomatic Colorectal Cancer,” Gut 63(2):317-325 (2014); Lofton-Day et al., “DNA Methylation Biomarkers for Blood-based Colorectal Cancer Screening,” Clinical Chemistry 54(2):414-423 (2008); Toth et al., “Detection of Methylated SEPT9 in Plasma is a Reliable Screening Method for Both Left- and Right-sided Colon Cancers,” PloS One 7(9):e46000 (2012); Warren et al., “Septin 9 Methylated DNA is a Sensitive and Specific Blood Test for Colorectal Cancer,” BMC Medicine 9:133 (2011); Lange et al., “Genome-scale Discovery of DNA-methylation Biomarkers for Blood-based Detection of Colorectal Cancer,” PloS One 7(11):e50266 (2012); Margolin et al., “Robust Detection of DNA Hypermethylation of ZNF154 as a Pan-Cancer Locus with in Silico Modeling for Blood-Based Diagnostic Development,” The Journal of Molecular Diagnostics: JMD 18(2):283-298 (2016); Lin et al., “Clinical Relevance of Plasma DNA Methylation in Colorectal Cancer Patients Identified by Using a Genome-Wide High-Resolution Array,” Ann. Surg. Oncol. 22 Suppl 3:S1419-1427 (2015); Pedersen et al., “Evaluation of an Assay for Methylated BCAT1 and IKZF1 in Plasma for Detection of Colorectal Neoplasia,” BMC Cancer 15:654 (2015), which are hereby incorporated by reference in their entirety). To ensure that these methylation sites were specific to CRC and not a result of aging-related methylation (McClay et al., “A Methylome-wide Study of Aging using Massively Parallel Sequencing of the Methyl-CpG-enriched Genomic Fraction from Blood in over 700 subjects,” Hum. Mol. Genet. 23(5):1175-1185 (2014), which is hereby incorporated by reference in its entirety), the Pearson correlation was calculated between levels of methylation and patient age. Furthermore, hypermethylation of these sites did not significantly correlate with MSI status, implying that markers have been identified for all CRC subtypes. Overall, ˜10,000 tissue samples, >4 billion datapoints (datapoint=CpG percentage methylation per sample) were analyzed to identify an initial list of few hundred CRC-specific markers. CpG markers consistently show up in many types of cancer and are labeled as potential Pan-Oncology markers. Additional approaches for detecting low abundance 5mC (or 5hmC) are described in WO2016057832A2, which is hereby incorporated by reference in its entirety, or using other suitable means known in the art.
Mutation or methylation status may give a clear analytical cut-off, i.e. the assay either records a mutation or CpG methylation event, and false-positives are a consequence of biology, for example from age-related methylation. With other markers there may be a greater overlap between marker level for individuals with cancer and their matched normal controls, especially in attempting to identify cancer at the earliest stages. In such cases, cut-offs may be defined by “Z-score”, 2 standard deviations above normal values, or by setting the false-positive rate at an arbitrary level, i.e. 5% when evaluating a suitable set of age-matched normal samples. Generally, the set of age-matched normal should be suitably large enough to set cut-off of the marker-specific signal from a given disease sample at >85%; >90%; >95%; >96%; >97%; or >98% of the same marker-specific signals from the set of normal samples. The “Z-score” may be calculated using the formula: Z=(X−μ)/σ; where Z=Z-score, X=each value in the dataset, μ=mean of all values in the dataset, and σ=standard deviation of a sample. Likewise, when using the Z-score, the cut-off for marker-specific signal from a given disease sample may be set at a z-score of >1.03; >1.28; >1.65; >1.75; >1.88; or >2.05 compared to the same marker-specific signals from the set of normal samples In some assays, marker levels, (i.e. DNA methylation levels for several gene promoter regions in plasma, or miRNA levels in urine) are quantified in relation to another marker, either internal or externally added in a qPCR reaction, where the cut-off is determined as a ΔCt value in the assay (Fackler et al., “Novel Methylated Biomarkers and a Robust Assay to Detect Circulating Tumor DNA in Metastatic Breast Cancer,” Cancer Res. 74(8):2160-70 (2014); U.S. Pat. No. 9,416,404 to Sukumar et al., which are hereby incorporated by reference in their entirety). Methylation status at defined promoter regions may also be determined using digital bisulfite genomic sequencing and digital MethyLight assays; using bisulfite conversion and preferential amplification of converted methylated sequences by blocking primers that interfere with amplification of converted unmethylated sequences; or depletion of unmethylated DNA using methyl-sensitive restriction endonucleases, followed by PCR (see U.S. Pat. No. 9,290,803 to Laird et al.; U.S. Pat. No. 9,476,100 to Frumkin et al.; U.S. Pat. No. 9,765,397 to McEvoy et at; U.S. Pat. No. 9,896,732 to Tabori et al.; U.S. Pat. No. 9,957,575 to Kottwitz et al., which are hereby incorporated by reference in their entirety). More recently, an elegant technique for bisulfite-free DNA sequencing has been developed based on using TET1 and pyridine-borane for conversion of 5mC and 5hmC to DHU (Liu et al., “Bisulfite-Free Direct Detection of 5-methylcytosine and 5-hydroxymethylcytosine at Base Resolution,” Nat Biotechnol. 37:424-429 (2019), which is hereby incorporated by reference in its entirety).
The genome-wide methylation profile of cfDNA (known as the methylome) can be determined using next-generation sequencing, and the methylation pattern may be used to identify the presence of fetal, tumor, or other tissue DNA in the plasma (Sun et al., “Plasma DNA Tissue Mapping by Genome-wide Methylation Sequencing for Noninvasive Prenatal, Cancer, and Transplantation Assessments,” Proc. Natl. Acad. Sci. USA 112(40):E5503-12 (2015); Lehmann-Werman et al., “Identification of Tissue-specific Cell Death Using Methylation Patterns of Circulating DNA,” Proc. Natl. Acad. Sci. USA 113(13):E1826-34 (2016); U.S. Pat. No. 9,732,390 to Lo et al.; U.S. Pat. No. 9,984,201 to Zhang et al., which are hereby incorporated by reference in their entirety).
While the above calculations are based on increasing the sensitivity of one or two markers, what if the average sensitivity of individual markers was increased from 50% to 66%?
The above tables, and
From the above charts, the receiver operating characteristic (ROC) curves may be calculated by plotting Sensitivity vs. 1-Specificity. Since these are theoretical calculations, the curves were generated for different levels of average marker false-positive rates of 2%, 3%, 4%, and 5%. The AUC values, calculated for ROC curves for 24 markers, with average individual marker at 66% Sensitivity with 2%-3% FP; 36 markers, with average individual marker at 66% Sensitivity with 2%-3% FP; and 48 markers, with average individual marker at 66% Sensitivity with 2%-3% FP; are provided in Table 23 below. Using the benchmark of an average of 150 molecules in the blood for the earliest cancer (Stage I), and looking only at the 3% individual marker FP rate AUC values are at 77% with 24 markers (average individual marker at 50% Sensitivity), improve to 87% with 24 markers (average individual marker at 66% Sensitivity); AUC values are at 87% with 36 markers (average individual marker at 50% Sensitivity), improve to 95% with 36 markers (average individual marker at 66% Sensitivity); and AUC values are at 89% with 48 markers (average individual marker at 50% Sensitivity), improve to 97% with 48 markers (average individual marker at 66% Sensitivity). These results illustrate that for multiple marker assays achieving good sensitivities and specificities for the earliest cancers is aided when the average individual marker sensitivity improves from 50% to 66%.
How would increasing the average individual marker sensitivity from 50% sensitivity to 66% sensitivity improve upon a one-step cancer assay? To review: the challenge is to screen 107 million adults in the U.S. over the age of 50 for colorectal cancer—of which there are about 135,000 new cases that are diagnosed a year. In this example, if there is an average of 300 molecules in the blood for early cancer (Stage I & II), and taking the best-case scenario of individual marker FP rate is 2%, then if there is a 3-marker minimum, then overall FP rate is 1.6% for 24 markers, for a specificity of 98.4% (See
However, if the individual marker FP rate is more realistic, say 4%, then more markers will be required to achieve better than 98% specificity, and this will be at the cost of sensitivity. If individual marker FP rate is 4%, then if there is a 5-marker minimum, then overall FP rate is 0.4% for 24 markers, for a specificity of 99.6% (See
Returning to the example of colorectal cancer, in particular the cases of microsatellite stable tumors (MSS) where the mutation load is low, for these calculations when relying on NGS sequencing alone (assuming 150 molecules with one mutation in the blood), an estimated 78% of early colorectal cancer would be missed. Again, to put these number in perspective, in the U.S., about 135,000 new cases of colorectal cancer were diagnosed in 2018, of which about 60% is late cancer (i.e. Stage III & IV). About 107 million individuals in the U.S. are over the age of 50 and should be tested for colorectal cancer. While it cannot be predicted how many individuals have a hidden cancer (i.e. Stage I) within them, who are non-compliant to testing, for the purposes of this calculation, assume that the average late cancer was once the average early cancer, and thus individuals with Stage I cancer would be about 40,500 individuals. With the assumption of these samples containing at least 150 molecules with one mutation in the blood, such a test would find 8,910 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. However, with a specificity for sequencing at 98%, there would be about 2.1 million false-positives. The positive predictive value of such a test would be around 0.4%, in other words, only one in 236 individuals who tested positive would actually have Stage I colorectal cancer, the rest would be false-positives. In contrast, consider the two-step methylation marker test described above, wherein the first step has 24 methylation markers specific to GI cancers, while the second step has 48 methylation markers specific to colorectal cancer. In this example, the average individual marker sensitivity is set at 66%. In this example, as above, the calculations are done with the anticipation of an average of 150 methylated (or hydroxymethylated) molecules per positive marker in the blood. Assuming individual marker false-positive rates of 3%, and with the first step requiring a minimum of 3 markers positive, then with an overall specificity of 94.6%, the first step would identify 5,778,000 individuals (out of 107,000,000 total adults over 50 in the U.S.) which would include at 76.2% sensitivity or about 30,861 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 5,778,000 presumptive positive individuals would be evaluated in the second step of 48 markers requiring a minimum of 5 markers positive, then the two-step test would identify 76.2%×90.0%=68.6%=27,775 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 5,778,000×4.2%=242,676 false-positives. The positive predictive value of such a test would be 27,775/270,451=10.3%, in other words, 1 in 10 individuals who tested positive would actually have Stage I colorectal cancer, an extraordinarily successful screen to focus on those patients who would most benefit from follow-up colonoscopy. Since >90% of individuals identified with Stage I colon cancer have long-term survival after just surgery, the benefit in lives saved would be of incalculable value.
How would the above numbers change if the initial test in the two-step assay uses 36 markers? In this example, as above, the calculations are done with the anticipation of an average of 150 methylated (or hydroxymethylated) molecules per positive marker in the blood. Assuming individual marker false-positive rates of 3%, and with the first step requiring a minimum of 4 markers positive, then with an overall specificity of 95.2%, the first step would identify 5,136,000 individuals (out of 107,000,000 total adults over 50 in the U.S.) which would include at 84.9% sensitivity or about 34,385 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 5,136,000 presumptive positive individuals would be evaluated in the second step of 48 markers requiring a minimum of 5 markers positive, then the two-step test would identify 84.9%×90.0%=76.4%=30,946 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 5,136,000×4.2%=215,712 false-positives. The positive predictive value of such a test would be 30,946/246,658=12.5%, in other words, 1 in 8 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. In expanding this example, the calculations are done with the anticipation that Stage I CRC has an average of 150 methylated (or hydroxymethylated) molecules per positive marker in the blood, Stage II CRC has an average of 200 methylated molecules per positive marker, and the higher stages (III & IV) have at least an average of 300 methylated molecules per positive marker, and the higher stages. Also, to be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals with Stage I cancer, 40,500 individuals with Stage II cancer, and the remaining 54,000 individuals have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 95.8% would be identified in the first step, of which 95.8%×98.0%=93.9%=38,023 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.8% would be identified in the first step, of which 99.8%×(100%)=53,892 individuals with late cancer would be identified. This brings the total identified at 30,946+38,023+53,892=122,861 individuals out of 135,000 with colorectal cancer. Overall, the positive predictive value of such a test would be 122,861/369,519=33.2%, in other words, 1 in 3 individuals who tested positive would actually have colorectal cancer, and this test would identify 68,969/81,000 or 85% of those individuals with early cancer—which would be unprecedented in diagnostic approaches to detect early cancer.
What if the goal is to minimize the total number of markers in an initial high-throughput cancer screen? What if the average sensitivity of individual markers was increased from 66% to 75%?
How would increasing the average individual marker sensitivity from 50% sensitivity to 75% sensitivity improve upon a one-step cancer assay? To review: the challenge is to screen 107 million adults in the U.S. over the age of 50 for colorectal cancer—of which there are about 135,000 new cases that are diagnosed a year. In this example, if there is an average of 300 molecules in the blood for early cancer (Stage I & II), and taking the best-case scenario of individual marker FP rate is 2%, then if there is a 3-marker minimum, then overall FP rate is 1.6% for 24 markers, for a specificity of 98.4% (See
However, if the individual marker FP rate is more realistic, e.g., 4%, then more markers will be required to achieve better than 98% specificity, and this will be at the cost of sensitivity. If individual marker FP rate is 4%, then, if there is a 5-marker minimum, the overall FP rate is 0.4% for 24 markers, for a specificity of 99.6% (See
Returning to the example of colorectal cancer, in particular the cases of microsatellite stable tumors (MSS) where the mutation load is low, for these calculations when relying on NGS sequencing alone (assuming 150 molecules with one mutation in the blood), an estimated 78% of early colorectal cancer would be missed. Again, to put these number in perspective, in the U.S., about 135,000 new cases of colorectal cancer were diagnosed in 2018, of which about 60% is late cancer (i.e. Stage III & IV). About 107 million individuals in the U.S. are over the age of 50 and should be tested for colorectal cancer. While it cannot be predicted how many individuals have a hidden cancer (i.e. Stage I) within them, who are non-compliant to testing, for the purposes of this calculation, assume that the average late cancer was once the average early cancer, and thus individuals with Stage I cancer would be about 40,500 individuals. With the assumption of these samples containing at least 150 molecules with one mutation in the blood, such a test would find 8,910 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. However, with a specificity for sequencing at 98%, there would be about 2.1 million false-positives. The positive predictive value of such a test would be around 0.4%, in other words, only one in 236 individuals who tested positive would actually have Stage I colorectal cancer, the rest would be false-positives. In contrast, consider a two-step methylation marker test, wherein the first step has 18 methylation markers specific to GI cancers with average sensitivity of 75%, while the second step has 36 methylation markers specific to colorectal cancer with average sensitivity of 75% (See
The ultimate goal is to develop a high-throughput scalable test to detect the majority of cancers that occur worldwide. A list for incidence of cancers worldwide may be found at: https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-cancer-data. The solid tumor cancers have been grouped into the following subclasses, as listed below in Tables 36, 37, and 38 for both sexes, for men, and for women.
The above list does not include liquid cancers, nor some of the less common solid tumors. Worldwide incidence (numbers in thousands) of liquid tumors include Non-Hodgkin lymphoma (225), Leukemia (187), Multiple Myeloma (70), and Hodgkin lymphoma (33). These would be detected in a separate test not discussed herein. Further, the list excludes Melanoma (287) and Brain tumors (134). Testing for these would be done with separate sets of markers, optimized as described above for colorectal cancer. In addition, while some cancers listed in the tables above are of extreme medical importance (Mesothelioma, Thyroid, the three different subcategories of Kidney cancer), their biology is sufficiently different as to usually merit a separate set of markers, again, optimized as described above for colorectal cancer.
Thus, for the present application, a Pan-Oncology test is developed that includes the following major cancers by the following groupings: Group 1 (colorectal, stomach, and esophagus); Group 2 (breast, endometrial, ovarian, cervical, and uterine); Group 3 (lung and head & neck); Group 4 (prostate and bladder); and Group 5 (liver, pancreatic, or gall bladder). Note that some cancers within Group 3 may be tested as a sputum sample, and cancers in Group 4 may be tested as a urine sample.
Careful analysis of the TCGA methylation database revealed a general commonality in methylation patterns among cancers within these 5 separate groups. Further, there are some methylation markers that are common among several cancers, while absent in normal white blood cells. Three different strategies were used to design a multi-step pan-oncology test.
The first strategy is to identify markers that cover multiple cancers in one or more of the above groups. The markers should be sufficiently diverse as to cover cancers in all 5 groups. For example, a first step of the assay would use a set of 96 markers that on average comprise at least 36 markers with 50% sensitivity that covers each of the aforementioned 16 types of solid tumors (covered in the 5 Groups; see
The second strategy is to identify markers that cover multiple cancers in one or more of the above groups. The markers should be sufficiently diverse as to cover cancers in all 5 groups. As before, a first step of the assay would use a set of 96 markers that on average comprise at least 36 markers with 50% sensitivity that covers each of the aforementioned 16 types of solid tumors (covered in the 5 Groups; see
The third strategy is to identify markers that cover as many cancers as possible, irrespective of group. The markers should be sufficiently diverse as to cover cancers in all 5 groups. For example, a first step of the assay would use a set of 48 markers that on average comprise of at least 24 markers with 75% sensitivity that covers each of the aforementioned 16 types of solid tumors (covered in the 5 Groups; see
Returning to the first strategy (see
Blood-based, solid tumor-specific microRNA markers derived through analysis of TCGA microRNA datasets, includes, but is not limited to the following markers: (mir ID, Gene ID); hsa-mir-21, MIR21; hsa-mir-182, MIR182; hsa-mir-454, MIR454; hsa-mir-96, MIR96; hsa-mir-183, MIR183; hsa-mir-549, MIR549; hsa-mir-301a, MIR301A; hsa-mir-548f-1, MIR548F1; hsa-mir-301b, MIR301B; hsa-mir-103-1, MIR1031; hsa-mir-18a, MIR18A; hsa-mir-147b, MIR147B; hsa-mir-4326, MIR4326; hsa-mir-573, MIR573. These markers may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood.
In addition,
Protein markers that can be secreted by solid tumors into the blood include, but are not limited to: (Protein name, UniProt ID); Uncharacterized protein C19orf48, Q6RUI8; Protein FAM72B, Q86X60; Protein FAM72D, Q6L9T8; Hydroxyacylglutathione hydrolase-like protein, Q6PII5; Putative methyltransferase NSUN5, Q96P11; RNA pseudouridylate synthase domain-containing protein 1, Q9UJJ7; Collagen triple helix repeat-containing protein 1, Q96CG8; Interleukin-11. P20809; Stromelysin-2, P09238; Matrix metalloproteinase-9, P14780; Podocan-like protein 1, Q6PEZ8; Putative peptide YY-2, Q9NRI6; Osteopontin, P10451; Sulthydryl oxidase 2, Q6ZRP7; Glypican-2, Q8N158; Macrophage migration inhibitory factor, P14174; Peptidyl-prolyl cis-trans isomerase A, P62937; Calreticulin, P27797.
A comparative analysis was performed across various TCGA datasets (tumors, normals), followed by an additional bioinformatics filter Meinken et al., “Computational Prediction of Protein Subcellular Locations in Eukaryotes: an Experience Report,” Computational Molecular Biology 2(1):1-7 (2012), which is hereby incorporated by reference in its entirety), which predicts the likelihood that the translated protein is secreted by the cells.
Commonly found mutations in solid tumors may be used as plasma-based markers of cancer, and they are available in the COSMIC and/or TCGA datasets: TP53 (tumor protein p53), TTN (titin), MUC16 (mucin 16), KRAS (K-Ras). Initial work identifying mutations in the plasma from patients with metastatic disease revealed an average of 5 mutations not only in the patients, but also in age-matched controls. A follow-up study using a 2 Mb, 508-gene panel and sequencing to more than 60,000-fold depth, showed mutations appeared in 93.6 percent of the white blood cells from individuals without cancer and 99.1 percent of those with cancer (Razavi et al., “Cell-free DNA (cfDNA) Mutations From Clonal Hematopoiesis: Implications for Interpretation of Liquid Biopsy Tests,” Journal of Clinical Oncology 35(15):11526-11526 (2017); Razavi et al., “High-intensity Sequencing Reveals the Sources of Plasma Circulating Cell-free DNA Variants,” Nature Medicine 25(12):1928-1937 (2019), which are hereby incorporated by reference in their entirety). This phenomenon, known as age-related clonal hematopoiesis, results from accumulation of mutations in white-blood cells, that then undergo clonal expansion. When screening for mutations markers in the plasma, it is important to always sequence an aliquot of WBC DNA from the same individual, such that a presumptive positive mutation is verified as arising from internal tissue (presumably corresponding to a tumor) and not due to clonal hematopoiesis.
A deep analysis of the TCGA database of methylation markers that are absent in blood but, on average, are present in solid tumor types at 50% sensitivity, show three general categories of clusters: (i) markers that are present in colorectal cancers, and related GI cancer (stomach & esophagus), (ii) markers that are present in colorectal cancers, and related GI cancer (stomach & esophagus), as well as other tumors, and (iii) markers that are mostly absent in colorectal cancers, but present in other tumors. Second, while for some tumor types one could readily identify markers that were unique to that group, such as Group 2 (breast, endometrial, ovarian, cervical, and uterine), for other tumor types such as Lung Cancer or Pancreatic Cancer, it was difficult to identify methylation markers that were unique to that cancer. Consequently, to assemble a set of 96 markers that satisfied the criteria of at least 36 markers with 50% sensitivity that covers each of the aforementioned 16 types of solid tumors, the first 48 markers comprised about 12 markers that were strongly represented in Group 2 tumors, about 12 markers that were strongly represented in Group 3 tumors, about 12 markers that were strongly represented in Group 4 tumors, and about 12 markers that were strongly represented in Group 5 tumors. The remaining 48 markers comprised about 12 markers that were strongly represented in Groups 1 and 2 tumors, about 12 markers that were strongly represented in Groups 1 and 3 tumors, about 12 markers that were strongly represented in Groups 1 and 4 tumors, and about 12 markers that were strongly represented in Groups 1 and 5 tumors.
Table 41 in the prophetic experimental section provides simulations of the 96-marker assay, with average sensitivities of 50%, for identifying the most probable group for tissue of origin, for both sexes. A set of 96 markers was assembled as above, and the percentage of samples positive within each of the cancer patients in the TCGA and GEO databases was assessed. The total number of patients for each cancer analyzed are: Group 1 (colorectal, CRC-PT=395; stomach, ST-Pt=260; esophagus, ES-Pt=185); Group 2 (breast, BR-Pt=668; endometrial, END-Pt=431; ovarian, OV-Pt=79; cervical, CERV-Pt=307; uterine, UTCS-Pt=57); Group 3 (lung adenocarcinoma, LUAD=450; lung squamous cell carcinoma, LUSC=372; head & neck, HNSC-Pt=528); Group 4 (prostate, PROS-Pt=192; bladder, BLAD-Pt=412); and Group 5 (liver, LIV-Pt=377; pancreatic, PANC-Pt=184; and gall bladder, BILE-Pt=36). The columns reflect the total percent patients positive for each of the markers divided by the total number of markers used—for the first row of all cancers, that would be 96 markers. Thus, on average, of the 96 markers chosen, the number of average sensitivity scores are: Group 1 (colorectal=44, stomach=45, esophagus=40); Group 2 (breast=38, endometrial=40, ovarian=22, cervical=39, uterine=33); Group 3 (lung adenocarcinoma=31, lung squamous cell carcinoma=31, head & neck=33); Group 4 (prostate=45, bladder=36); and Group 5 (liver=38, pancreatic=27, gall bladder=47). This translates into the following number of marker equivalents with average sensitivities of 50% (=96×score/50); (colorectal=85 marker equivalents; stomach=86 marker equivalents; esophagus=78 marker equivalents); Group 2 (breast=74 marker equivalents; endometrial=76 marker equivalents; ovarian=42 marker equivalents; cervical=75 marker equivalents; uterine=64 marker equivalents); Group 3 (lung adenocarcinoma=60 marker equivalents; lung squamous cell carcinoma=59 marker equivalents; head & neck=64 marker equivalents); Group 4 (prostate=86 marker equivalents; bladder=70 marker equivalents); and Group 5 (liver=74 marker equivalents; pancreatic=51 marker equivalents; gall bladder=91 marker equivalents). Thus, cancers were well represented, ranging from 42 to 91 marker equivalents for the different cancer types, and all were well above the minimum of 36 markers with average sensitivities of 50%.
The above numbers translate into the following number of marker equivalents with average sensitivities of 66% (=96×score/66); (colorectal=65 marker equivalents; stomach=65 marker equivalents; esophagus=59 marker equivalents); Group 2 (breast=56 marker equivalents; endometrial=58 marker equivalents; ovarian=32 marker equivalents; cervical=57 marker equivalents; uterine=48 marker equivalents); Group 3 (lung adenocarcinoma=45 marker equivalents; lung squamous cell carcinoma=45 marker equivalents; head & neck=48 marker equivalents); Group 4 (prostate=65 marker equivalents; bladder=53 marker equivalents); and Group 5 (liver=56 marker equivalents; pancreatic=39 marker equivalents; gall bladder=69 marker equivalents). Thus, cancers were well represented, ranging from 32 to 69 marker equivalents for the different cancer types, and, with the exception of ovarian cancer at 32, the other cancer types are above the minimum of 36 markers with average sensitivities of 66%.
The aforementioned markers were then re-ordered for each of the above cancer types such that the most prevalent markers were listed first. For example, with CRC, of the 96 markers, 54 markers gave scores above 55 (i.e. were positive in greater than 55% of the 395 patients) and 9 gave scores of between 25 and 54 (i.e. were positive for from 25% to 54% of the 395 patients). Half of the higher, and a third of the lower set, for a total of 30 markers, were distributed into two marker test sets, designated “CRC1” and “CRC2” (Table 41, rows 2 & 3). These marker sets would reflect an ideal result if half the markers with the potential to be positive are detected in the assay. This does not account for the chances that earlier stage tumors would have a lower number of marker molecules in the plasma, and thus, consequently, the actual number of markers positive would be less than the ideal result in this simulation. The percent of patients positive for each of the cancers was recorded and then divided by the total number of markers used for that cancer type. As anticipated, when selecting markers for a given tumor type, those markers should give a higher score than the average, i.e. 66 for CRC in each of the two sets of selected 30 markers, compared with a score of 44 for the unselected 96 markers. These markers form a diagonal across Table 41 and are highlighted in bold and light grey background.
For each column, marker sets that are in the same range or higher than the number of positive markers for that cancer type are also shown with a light grey background. For example, a patient with colorectal, stomach, or esophageal cancer will be scored as potentially positive with stomach cancer. This makes sense as the markers for these three cancers overlap, and they all bin to Group 1. So they could be distinguished in step 2 of the assay on the group 1 markers, wherein these markers are more cancer types specific, to tease out the most probable cancer type. Evaluation of the ST-Pt column shows that simulations for one of the two LUAD, BLAD, and both PANC also gave scores that might be interpreted as stomach cancer. Thus, the first step is not always able to pinpoint what Groups should be tested in the second step of the assay. However, most of the ambiguity is within group members (i.e. Group 2), and this makes sense, since the markers were chosen to maximize the ability to chose which groups to test in the second step.
Tables 42 and 43 (see prophetic experimental section) take the aforementioned results in the simulations in Table 41 and multiplies them by the percent incidence of the given cancer type for that gender (see Tables 37 and 38 respectively). The result is adjusted to the same order of magnitude (multiple by 10). The concept is for the physician to take into account that a lower score for a high incidence cancer (such as CRC) may be a more common tissue of origin for a higher score for a low incidence cancer (such as lung squamous cell carcinoma). Tables 42 and 43 show the level of ambiguity in identifying tissue of origin is higher among female patients than among male patients, as indicated by the number of cells highlighted in grey that are not on the diagonal. In all cases, the physician will need to incorporate all data, such as smoking history, not just molecular data, to determine the most likely tissue of origin before sending the patient to confirmatory imaging.
Tables 44, 45, and 46 (see prophetic experimental section) take the aforementioned results in the simulations in Tables 41, 42, and 43 and determines the percent deviation from the neutral result by taking the percentage of (=score specific cancer type simulation/score all cancer for that type−1). Thus, the first row of each of these tables should be 0%. Again, those percentages that are higher than, or in the same range as, the percentages across the diagonal are highlighted in light gray. While this set of marker selection may be less than ideal for distinguishing esophageal or gall bladder cancers as the tissue of origin, they are nevertheless quite informative for guiding the physician to which groups of the Step 2 assays should be tested. This simple scoring may be augmented by using AI approaches based on a database of results with clinical samples using the aforementioned 96-marker set.
For the second step of the assay, one or two or more of the following groups will be tested, each group with a set of 64 markers that on average comprise at least 36 markers with 50% sensitivity that covers each of the aforementioned 16 types of solid tumors, in the following groups: Group 1 (colorectal, stomach, and esophagus); Group 2 (breast, endometrial, ovarian, cervical, and uterine); Group 3 (lung and head & neck); Group 4 (prostate and bladder); and Group 5 (liver, pancreatic, or gall bladder). These Group-specific and cancer type-specific markers include, but are not limited to, cancer-specific microRNA markers, cancer-specific ncRNA and lncRNA markers, cancer-specific exon transcripts, tumor-associated antigens, cancer protein markers, protein markers that can be secreted by solid tumors into the blood, common mutations, primary CpG sites that are solid tumor and tissue specific markers, chromosomal regions or sub-regions within which are primary CpG sites that are solid tumor and tissue specific markers, and primary and flanking CpG sites that are solid tumor and tissue specific markers. Methods for detecting said markers have been discussed supra, and Figures listing these markers are described for each of the groups below.
Group 1 (colorectal, stomach, and esophagus): Blood-based, colorectal, stomach, and esophageal cancer-specific microRNA markers that may be used to distinguish group 1 from other groups include, but are not limited to: (mir ID, Gene ID): hsa-mir-624, MIR624. This miRNA was identified through analysis of TCGA microRNA datasets, and may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood.
Blood-based, colorectal, stomach, and esophageal cancer-specific ncRNA and lncRNA markers that may be used to distinguish group 1 from other groups include, but are not limited to: [Gene ID, Coordinate (GRCh38)], ENSEMBL ID: LINC01558, chr6:167784537-167796859, ENSG00000146521.8. This ncRNA was identified through comparative analysis of various publicly available Affymetrix Exon ST CEL data, which were aligned to GENCODE annotations to generate ncRNA and lncRNA transcriptome datasets. Such lncRNA and ncRNA may be enriched in exosomes or other protected states in the blood.
In addition,
Colorectal, stomach, and esophageal cancer protein encoding markers that may be used to distinguish group 1 from other groups include, but are not limited to: (Gene Symbol, Chromosome Band Gene Title, UniProt ID): SELE, 1q22-q25, selectin E, P16581; OTUD4, 4q31.21, OTU domain containing 4, Q01804; BPI, 20q11.23, bactericidal/permeability-increasing protein, P17213; ASB4, 7q21-q22, ankyrin repeat and SOCS box containing 4, Q9Y574; C6orf123, 6q27, chromosome 6 open reading frame 123, Q9Y6Z2; KPNA3, 13q14.3, karyopherin alpha 3 (importin alpha 4), 000505; NUP98, 11p15, nucleoporin 98 kDa, P52948, identified through mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product arising from colorectal, stomach, and esophageal cancers, which may be identified in the blood, either within exosomes, other protected states, tumor-associated vesicles, or free within the plasma.
Protein markers that can be secreted by colorectal, stomach, and esophageal cancer into the blood, and may be used to distinguish group 1 from other groups include, but are not limited to: (Protein name, UniProt ID); Bactericidal permeability-increasing protein (BPI) (CAP 57), P1721. A comparative analysis was performed across various TCGA datasets (tumors, normals), followed by an additional bioinformatics filter (Meinken et al., “Computational Prediction of Protein Subcellular Locations in Eukaryotes: an Experience Report,” Computational Molecular Biology 2(1):1-7 (2012), which is hereby incorporated by reference in its entirety), which predicts the likelihood that the translated protein is secreted by the cells.
The distribution of mutations in colorectal, stomach, and esophageal cancer are available in the public COSMIC database, with the most common being: APC (APC regulator of WNT signaling pathway), ATM (ATM serine/threonine kinase), CSMD1 (CUB and Sushi multiple domains 1), DNAH11 (dynein axonemal heavy chain 11), DST (dystonin), EP400 (E1A binding protein p400), FAT3 (FAT atypical cadherin 3), FAT4 (FAT atypical cadherin 4), FLG (filaggrin), GLI3 (GLI family zinc finger 3), KRAS (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), LRP1B (LDL receptor related protein 1B), MUC16 (mucin 16, cell surface associated), OBSCN (obscurin, cytoskeletal calmodulin and titin-interacting RhoGEF), PCLO (piccolo presynaptic cytomatrix protein), PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha), RYR2 (ryanodine receptor 2), SYNE1 (spectrin repeat containing nuclear envelope protein 1), TP53 (tumor protein p53), TTN (titin), and UNC13C (unc-13 homolog C).
Group 2 (breast, endometrial, ovarian, cervical, and uterine): Blood-based, breast, endometrial, ovarian, cervical, and uterine cancer-specific microRNA markers may be used to distinguish group 2 from other groups include, but are not limited to: (mir ID, Gene ID): hsa-mir-1265, MIR1265. This marker was identified through analysis of TCGA microRNA datasets, which may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood.
Blood-based breast, endometrial, ovarian, cervical, and uterine cancer-specific exon transcripts may be used to distinguish group 2 from other groups include, but are not limited to: (Exon location, Gene); chr2:179209013-179209087:+, OSBPL6; chr2:179251788-179251866:+, OSBPL6; and chr2:179253736-179253880:+, OSBPL6, and may be enriched in exosomes, tumor-associated vesicles, or other protected states in the blood.
Breast, endometrial, ovarian, cervical, and uterine cancer protein markers, identified through mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product arising from breast, endometrial, ovarian, cervical, and uterine cancer protein markers, may be used to distinguish group 2 from other groups include, but are not limited to: (Gene Symbol, Chromosome Band, Gene Title, UniProt ID): RSPO2, 8q23.1, R-spondin 2, Q6UXX9; KLC4, 6p21.1, kinesin light chain 4, Q9NSK0; GLRX, 5q14, glutaredoxin (thioltransferase), P35754. These markers may be identified through mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product arising from breast, endometrial, ovarian, cervical, and uterine cancers, which may be identified in the blood, either within exosomes, other protected states, tumor-associated vesicles, or free within the plasma.
Protein markers that can be secreted by breast, endometrial, ovarian, cervical, and uterine cancer into the blood may be used to distinguish group 2 from other groups include, but are not limited to: (Protein name, UniProt ID); R-spondin-2 (Roof plate-specific spondin-2) (hRspo2), Q6UXX9. A comparative analysis was performed across various TCGA datasets (tumors, normals), followed by an additional bioinformatics filter (Meinken et al., “Computational Prediction of Protein Subcellular Locations in Eukaryotes: an Experience Report,” Computational Molecular Biology 2(1):1-7 (2012), which is hereby incorporated by reference in its entirety), which predicts the likelihood that the translated protein is secreted by the cells.
The distribution of mutations in breast, endometrial, ovarian, cervical, and uterine cancer are available in the public COSMIC database, with the 20 most commonly altered genes listed as: PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha), and TTN (titin).
Group 3 (lung adenocarcinoma, lung squamous cell carcinoma, and head & neck): Blood-based, lung, head, and neck cancer-specific microRNA markers may be used to distinguish group 3 from other groups include, but are not limited to: (mir ID, Gene ID): hsa-mir-28, MIR28. This marker was identified through analysis of TCGA microRNA datasets, and may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood.
Blood-based lung, head, and neck cancer-specific exon transcripts may be used to distinguish group 3 from other groups include, but are not limited to: (Exon location, Gene); chr2: chr1:93307721-93309752:−, FAM69A; chr1:93312740-93312916:−, FAM69A; chr1:93316405-93316512:−, FAM69A; chr1:93341853-93342152:−, FAM69A; chr1:93426933-93427079:−, FAM69A; chr7:40221554-40221627:+, C7orf10; chr7:40234539-40234659:+, C7orf10;chr8:22265823-22266009:+, SLC39A14; chr8:22272293-22272415:+, SLC39A14; chr14:39509936-39510091:−, SEC23A; chr14:39511990-39512076:−, SEC23A, and may be enriched in exosomes, tumor-associated vesicles, or other protected states in the blood.
Lung, head, and neck cancer protein encoding markers that may be used to distinguish group 3 from other groups include, but are not limited to: (Gene Symbol, Chromosome Band, Gene Title, UniProt ID): STRN3, 14q13-q21, striatin, calmodulin binding protein 3, Q13033; LRRC17, 7q22.1, leucine rich repeat containing 17, Q8N6Y2; FAM69A, 1p22, family with sequence similarity 69, member A, Q5T7M9; ATF2, 2q32, activating transcription factor 2, P15336; BHMT, 5q14.1, betaine-homocysteine S-methyltransferase, Q93088; ODZ3/TENM3, 4q34.3-q35.1, teneurin transmembrane protein 3, Q9P273; ZFHX4, 8q21.11, zinc finger homeobox 4, Q86UP3. These markers may be identified through mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product arising from lung, head, and neck cancers, which may be identified in the blood, either within exosomes, other protected states, tumor-associated vesicles, or free within the plasma.
Protein markers that can be secreted by lung, head, and neck cancer into the blood may be used to distinguish group 3 from other groups include, but are not limited to: (Protein name, UniProt ID); Leucine-rich repeat-containing protein 17 (p37NB), Q8N6Y2. A comparative analysis was performed across various TCGA datasets (tumors, normals), followed by an additional bioinformatics filter (Meinken et al., “Computational Prediction of Protein Subcellular Locations in Eukaryotes: an Experience Report,” Computational Molecular Biology 2(1):1-7 (2012), which is hereby incorporated by reference in its entirety), which predicts the likelihood that the translated protein is secreted by the cells.
The distribution of mutations in lung, head, and neck cancer are available in the public COSMIC database, with the most common being: CSMD3 (CUB and Sushi multiple domains 3), DNAH5 (dynein axonemal heavy chain 5), FAT1 (FAT atypical cadherin 1), FLG (filaggrin), KRAS (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), LRP1B (LDL receptor related protein 1B), MUC16 (mucin 16, cell surface associated), PCLO (piccolo presynaptic cytomatrix protein), PKHD1L1 (PKHD1 like 1), RELN (reelin), RYR2 (ryanodine receptor 2), SI (sucrase-isomaltase), SYNE1 (spectrin repeat containing nuclear envelope protein 1), TP53 (tumor protein p53), TTN (titin), USH2A (usherin), and XIRP2 (xin actin binding repeat containing 2).
Group 4 (prostate and bladder): Blood or urine-based, prostate and bladder cancer-specific microRNA markers may be used to distinguish group 4 from other groups include, but are not limited to: (mir ID, Gene ID): hsa-mir-491, MIR491; hsa-mir-1468, MIR1468. These markers were identified through analysis of TCGA microRNA datasets, and may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood or urine.
Blood or urine-based, prostate and bladder cancer-specific ncRNA and lncRNA markers may be used to distinguish group 4 from other groups include, but are not limited to: [Gene ID, Coordinate (GRCh38), ENSEMBL ID]: AC007383.3, chr2:206084605-206086564, ENSG00000227946.1; LINC00324, chr17:8220642-8224043, ENSG00000178977.3. These markers were identified through comparative analysis of various publicly available Affymetrix Exon ST CEL data, which were aligned to GENCODE annotations to generate ncRNA and lncRNA transcriptome datasets. Such lncRNA and ncRNA may be enriched in exosomes or other protected states in the blood or urine.
Blood or urine-based prostate and bladder cancer-specific exon transcripts may be used to distinguish group 4 from other groups include, but are not limited to: (Exon location, Gene); chr21:45555942-45556055:+, C21orf33 and may be enriched in exosomes, tumor-associated vesicles, or other protected states in the blood or urine.
Prostate and bladder cancer protein markers that may be used to distinguish group 4 from other groups include, but are not limited to: (Gene Symbol, Chromosome Band, Gene Title, UniProt ID): PMM1, 22q13, phosphomannomutase 1, Q92871. This marker may be identified through mRNA sequences, protein expression levels, protein product concentrations, cytokines, or autoantibody to the protein product arising from lung, head, and neck cancers, which may be identified in the blood, either within exosomes, other protected states, tumor-associated vesicles, or free within the plasma, or within the urine.
The distribution of mutations in prostate and bladder cancer are available in the public COSMIC database, with the most common being: BAGE2 (BAGE family member 2), DNM1P47 (dynamin 1 pseudogene 47), FRG1BP (region gene 1 family member B, pseudogene), KRAS (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), RP11-156P1.3, TTN (titin), and TUBB8P7 (tubulin beta 8 class VIII pseudogene 7).
Group 5 (liver, pancreatic and gall-bladder): Blood-based, liver, pancreatic and gall-bladder cancer-specific microRNA markers may be used to distinguish group 5 from other groups include, but are not limited to: (mir ID, Gene ID): hsa-mir-132, MIR132. This marker was identified through analysis of TCGA microRNA datasets, which may be present in exosomes, tumor-associated vesicles, Argonaute complexes, or other protected states in the blood.
In addition,
Protein markers that can be secreted by liver, pancreatic and gall-bladder cancer into the blood may be used to distinguish group 5 from other groups include, but are not limited to: (Protein name, UniProt ID); Gelsolin (AGEL) (Actin-depolymerizing factor) (ADF) (Brevin), P06396; Pro-neuregulin-2, 014511; CD59 glycoprotein (1F5 antigen) (20 kDa homologous restriction factor) (HRF-20) (HRF20) (MAC-inhibitory protein) (MAC-IP) (MEM43 antigen) (Membrane attack complex inhibition factor) (MACIF) (Membrane inhibitor of reactive lysis) (MIRL) (Protectin) (CD antigen CD59), P13987; Divergent protein kinase domain 2B (Deleted in autism-related protein 1), Q9H7Y0. A comparative analysis was performed across various TCGA datasets (tumors, normals), followed by an additional bioinformatics filter (Meinken et al., “Computational Prediction of Protein Subcellular Locations in Eukaryotes: an Experience Report,” Computational Molecular Biology 2(1):1-7 (2012), which is hereby incorporated by reference in its entirety), which predicts the likelihood that the translated protein is secreted by the cells.
The distribution of mutations in liver, pancreatic and gall-bladder cancer are available in the public COSMIC database, with the most common being: KRAS (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), MUC16 (mucin 16, cell surface associated), MUC4 (mucin 4, cell surface associated), TP53 (tumor protein p53), and TTN (titin).
Returning now to the strategy wherein in the first step is to identify markers that cover as many cancers as possible, irrespective of group, and yet are sufficiently diverse as to cover cancers in all 5 groups (
A deep analysis of the TCGA database of methylation markers that are absent in blood but on average are present in many solid tumor types at 75% sensitivity show a paucity of markers for pancreatic, lung adenocarcinoma, lung squamous cell carcinoma, and ovarian cancer. Consequently, to assemble a set of 64 markers that satisfied the criteria of at least 36 markers with 75% sensitivity that covers each of the aforementioned 16 types of solid tumors, the markers were focused on coverage of those cancers first, and bringing up the numbers for the other cancers by choosing markers that were well represented for other cancers as well, with the following average sensitivity scores: Group 1 (colorectal=75, stomach=68, esophagus=72); Group 2 (breast=66, endometrial=73, ovarian=54, cervical=73, uterine=67); Group 3 (lung adenocarcinoma=54, ung squamous cell carcinoma=58, head & neck=64); Group 4 (prostate=72, bladder=63); and Group 5 (liver=53, pancreatic=45, gall bladder=68). This translates into the following number of marker equivalents with average sensitivities of 75% (=64×score/75); (colorectal=64 marker equivalents; stomach=58 marker equivalents; esophagus=61 marker equivalents); Group 2 (breast=57 marker equivalents; endometrial=62 marker equivalents; ovarian=46 marker equivalents; cervical=62 marker equivalents; uterine=57 marker equivalents); Group 3 (lung adenocarcinoma=46 marker equivalents; lung squamous cell carcinoma=49 marker equivalents; head & neck=54 marker equivalents); Group 4 (prostate=61 marker equivalents; bladder=53 marker equivalents); and Group 5 (liver=45 marker equivalents; pancreatic=39 marker equivalents; gall bladder=58 marker equivalents). Thus, cancers were well represented, ranging from 39 to 64 marker equivalents for the different cancer types, and all above the minimum of 36 markers with average sensitivities of 75%.
For the second step of the assay in
The aforementioned markers with average sensitivities of 75% may also be used to monitor recurrence in melanoma. Primer sets for exemplary preferred and alternate methylation markers are listed in Table 57 in the prophetic experimental section.
How would the different Pan-oncology tests compare with each other for detecting either colorectal cancer (both sexes) or ovarian cancer in the US? For the illustrative examples below: (1) The pan-oncology test of 96 markers with average sensitivities of 50% wherein >36 markers/group are positive with each cancer. For colorectal=84 marker equivalents; for ovarian=42 marker equivalents. The marker false-positive rates of 3%, for colorectal cancer will be calculated at 48 markers, while for ovarian cancer will be calculated at 36 markers, with a minimum of 5 positives to go to Step 2 or imaging. (2) The pan-oncology test of 64 markers with average sensitivities of 75% wherein >36 markers/group are positive with each cancer. For colorectal=64 marker equivalents; for ovarian=46 marker equivalents. The marker false-positive rate of 3%, for colorectal cancer will be calculated at 48 markers, while for ovarian cancer will be calculated at 36 markers, with a minimum of 5 positives to go to Step 2. (3) The group-specific step of 64 markers with average sensitivities of 50% wherein >36 markers/group are positive with each cancer. For colorectal=61 marker equivalents; for ovarian=41 marker equivalents. The marker false-positive rates of 3%, for colorectal cancer will be calculated at 48 markers, while for ovarian cancer will be calculated at 36 markers, with a minimum of 5 positives to go to imaging. (4) The group-specific step of 48 markers with average sensitivities of 75% wherein >36 markers/group are positive with each cancer. For colorectal=56 marker equivalents; for ovarian=45 marker equivalents. The marker false-positive rates of 3%, for colorectal cancer will be calculated at 48 markers, while for ovarian cancer will be calculated at 36 markers, with a minimum of 5 positives to go to imaging.
Consider the first strategy using the 96 pan-oncology markers of detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (48 markers for CRC) with average sensitivities of 50%, requiring a minimum of 5 markers positive, and an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the U.S.). This would include, at 90.1% sensitivity, or about 36,490 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 64 markers (48 markers for CRC) with average sensitivities of 50%, requiring a minimum of 5 markers positive. The two-step test would identify 90.1%×90.1%=81.2%=32,877 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 32,877/(188,748+32,877)=14.8%. In other words, 1 in 6.7 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that, as the test is used repeatedly, more of early and less of late CRC will be detected, an estimated 40,500 individuals with Stage I cancer, 40,500 individuals with Stage II cancer, and 54,000 individuals with late-stage cancer (135,000 total individuals with colorectal cancer) would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 90.1% would be identified in the first step, of which 97.2%×97.2%=94.5%=38,263 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.3% would be identified in the first step, of which 99.3%×99.3%=98.6%=53,246 individuals with late cancer would be identified. This brings the total identified to 32,877+38,263+53,246=124,386 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 92.1%. Overall, the positive predictive value of such a test would be 124,386/(188,748+124,386)=39.7%. In other words, 1 in 2.5 individuals who tested positive would actually have colorectal cancer, and this test would identify 71,104/81,000 or 87.7% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using this strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (36 markers for ovarian) with average sensitivities of 50%, and requiring a minimum of 5 markers positive, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S.) with ovarian cancer. This would include at, 71.5% sensitivity, about 3,932 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 64 markers (36 markers for ovarian cancer) with average sensitivities of 50%, requiring a minimum of 5 markers positive. The two-step test would identify 71.5%×71.5%=51.1%=2,810 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 2,810/(4,374+2,810)=39.1%. In other words, 1 in 2.5 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. As the test is used repeatedly, assume all four stages are at 5,500, and, therefore, 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 84.4% would be identified in the first step, of which 84.4%×84.4%=71.2%=3,916 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 94.5% would be identified in the first step, of which 94.5%×94.5%=89.3%=9,823 individuals with late ovarian cancer would be identified. This brings the total identified to 2,810+3,916+9,823=16,549 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 75.2%. Overall, the positive predictive value of such a test would be 16,549/(16,549+4,374)=79.0%. In other words, 4 in 5 women who tested positive would actually have ovarian cancer. This test would identify 6,006/11,000 or 54.6% of those individuals with early cancer, compared with the current rate of 15%.
Consider the strategy of using the 96 pan-oncology markers for detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, and with the first step using 96 markers (48 markers for CRC) with average sensitivities of 50%, requiring a minimum of 5 markers positive, then, with an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the U.S.). This would include at 90.1% sensitivity, or about 36,490 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 48 markers (48 markers for CRC) with average sensitivities of 75%, requiring a minimum of 5 markers positive. The two-step test would identify 90.1%×99.2%=89.4%=36,198 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 36,198/(188,748+36,198)=16.1%. In other words, 1 in 6.2 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals would have Stage I cancer, 40,500 individuals would have Stage II cancer, and the remaining 54,000 individuals would have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 97.2% would be identified in the first step, of which 97.2%×99.9%=97.1%=39,325 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.3% would be identified in the first step, of which 99.3%×99.9%=99.2%=53,568 individuals with late cancer would be identified. This brings the total identified at 36,198+39,325+53,568=129,091 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 95.6%. Overall, the positive predictive value of such a test would be 129,091/(188,748+129,091)=40.6%, in other words, 1 in 2.5 individuals who tested positive would actually have colorectal cancer, and this test would identify 75,523/81,000 or 93.2% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using the second strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (36 markers for Ovarian) with average sensitivities of 50%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S.). This would include, at 71.5% sensitivity, about 3,932 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 48 markers (36 markers for ovarian cancer) with average sensitivities of 75%, requiring a minimum of 5 markers positive. The two-step test would identify 71.5%×94.5%=67.6%=3,718 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 3,718/(4,374+3,718)=45.9%. In other words, 1 in 2.2 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. Assuming all four stages are at 5,500, then 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 84.4% would be identified in the first step, of which 84.4%×98.3%=82.9%=4,559 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 94.5% would be identified in the first step, of which 94.5%×99.7%=94.2%=10,363 individuals with late ovarian cancer would be identified. This brings the total identified at 3,718+4,559+10,363=18,640 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 84.7%. Overall, the positive predictive value of such a test would be 18,640/(18,640+4,374)=81.0%. In other words, 4 in 5 women who tested positive would actually have ovarian cancer, and this test would identify 8,277/11,000 or 75.2% of those individuals with early cancer, compared with the current rate of 15%.
Finally, consider the third strategy using the 64 pan-oncology markers of detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 64 markers (48 markers for CRC) with average sensitivities of 75%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the U.S.). This would include, at 99.2% sensitivity, about 40,176 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 96 markers (48 markers for CRC) with average sensitivities of 50%, requiring a minimum of 5 markers positive. The two-step test would identify 99.2%×90.1%=89.3%=36,198 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 36,198/(188,748+36,198)=16.1%. In other words, 1 in 6.2 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals would have Stage I cancer, 40,500 individuals would have Stage II cancer, and the remaining 54,000 individuals would have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 99.9% would be identified in the first step, of which 99.9%×97.2%=97.1%=39,325 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.9% would be identified in the first step, of which 99.9%×99.3%=99.2%=53,568 individuals with late cancer would be identified. This brings the total identified at 36,198+39,325+53,568=129,091 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 95.6%. Overall, the positive predictive value of such a test would be 129,091/(188,748+129,091)=40.6%. In other words, 1 in 2.5 individuals who tested positive would actually have colorectal cancer, and this test would identify 75,523/81,000 or 93.2% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using the third strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 64 markers (36 markers for ovarian) with average sensitivities of 75%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S.). This would include, at 94.5% sensitivity, about 5,197 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 96 markers (36 markers for ovarian cancer) with average sensitivities of 50%, requiring a minimum of 5 markers positive. The two-step test would identify 94.5%×71.5%=67.6%=3,718 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 3,718/(4,374+3,718)=45.9%. In other words, 1 in 2.2 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. Also, assume all four stages are at 5,500, then 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 84.4% would be identified in the first step, of which 98.3%×84.4%=82.9%=4,559 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 94.5% would be identified in the first step, of which 99.7%×94.5%=94.2%=10,363 individuals with late ovarian cancer would be identified. This brings the total identified at 3,718+4,559+10,363=18,640 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 84.7%. Overall, the positive predictive value of such a test would be 18,640/(18,640+4,374)=81.0%. In other words, 4 in 5 women who tested positive would actually have ovarian cancer, and this test would identify 8,277/11,000 or 75.2% of those individuals with early cancer, compared with the current rate of 15%.
The above calculations worked under the assumption of limiting at least one set of markers to an average of 50% sensitivities. How would the results improve if the average of 50% sensitivities was improved to 66% sensitivities?
Consider the first strategy using the 96 pan-oncology markers of detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (48 markers for CRC) with average sensitivities of 66%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the U.S). This would include, at 98.0% sensitivity, about 39,690 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 64 markers (48 markers for CRC) with average sensitivities of 66%, requiring a minimum of 5 markers positive. The two-step test would identify 98.0%×98.0%=96.0%=38,896 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 38,896/(188,748+38,896)=17.81%. In other words, 1 in 6 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals would be identified with Stage I cancer, 40,500 individuals would be identified with Stage II cancer, and the remaining 54,000 individuals would have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 98.0% would be identified in the first step, of which 99.6%×99.6%=99.2%=40,176 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.9% would be identified in the first step, of which 99.9%×99.9%=99.8%=53,568 individuals with late cancer would be identified. This brings the total identified at 38,896+40,176+53,892=132,964 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 98.5%. Overall, the positive predictive value of such a test would be 132,964/(188,748+132,964)=41.3%. In other words, 1 in 2.5 individuals who tested positive would actually have colorectal cancer, and this test would identify 79,072/81,000 or 97.6% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using the first strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (36 markers for ovarian) with average sensitivities of 66%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S). This would include, at 90.0% sensitivity, about 4,950 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 64 markers (36 markers for ovarian cancer) with average sensitivities of 66%, requiring a minimum of 5 markers positive. The two-step test would identify 90.0%×90.0%=81.0%=4,895 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 4,895/(4,374+4,895)=52.8%. In other words, 1 in 2 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. Also, assume all four stages are at 5,500, then 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 96.2% would be identified in the first step, of which 96.2%×96.2%=92.5%=5,087 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 99.2% would be identified in the first step, of which 99.2%×99.2%=98.4%=10,824 individuals with late ovarian cancer would be identified. This brings the total identified at 4,895+5087+10,824=20,806 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 94.6%. Overall, the positive predictive value of such a test would be 20,806/(20,806+4,374)=87.4%. In other words, 7 in 8 women who tested positive would actually have ovarian cancer, and this test would identify 9,982/11,000 or 90.1% of those individuals with early cancer, compared with the current rate of 15%.
Consider the second strategy using the 96 pan-oncology markers of detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (48 markers for CRC) with average sensitivities of 66%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the U.S). This would include, at 98.0% sensitivity, about 39,690 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 48 markers (48 markers for CRC) with average sensitivities of 75%, requiring a minimum of 5 markers positive. The two-step test would identify 98.0%×99.2%=97.2%=39,372 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 39,372/(188,748+39,372)=17.2%. In other words, 1 in 5.8 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals would be identified with Stage I cancer, 40,500 individuals would be identified with Stage II cancer, and the remaining 54,000 individuals would have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 99.6% would be identified in the first step, of which 99.6%×99.9%=99.5%=40,297 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.9% would be identified in the first step, of which 99.9%×99.9%=99.8%=53,892 individuals with late cancer would be identified. This brings the total identified at 39,372+40,297+53,892=133,561 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 98.9%. Overall, the positive predictive value of such a test would be 133,561/(188,748+133,561)=41.4%. In other words, 1 in 2.4 individuals who tested positive would actually have colorectal cancer, and this test would identify 79,699/81,000 or 98.4% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using the second strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 96 markers (36 markers for ovarian) with average sensitivities of 66%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S). This would include, at 90.0% sensitivity, about 4,950 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 48 markers (36 markers for ovarian cancer) with average sensitivities of 75%, requiring a minimum of 5 markers positive. The two-step test would identify 90.0%×94.5%=85%=4,675 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 4,675/(4,374+4,675)=51.6%. In other words, 1 in 2 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. Also, assume all four stages are at 5,500, then 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 96.2% would be identified in the first step, of which 96.2%×98.3%=94.5%=5,201 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 99.2% would be identified in the first step, of which 99.2%×99.7%=98.9%=10,879 individuals with late ovarian cancer would be identified. This brings the total identified at 4,675+5,201+10,879=20,755 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 94.3%. Overall, the positive predictive value of such a test would be 20,755/(20,755+4,374)=82.6%. In other words, 4 in 5 women who tested positive would actually have ovarian cancer, and this test would identify 9,876/11,000 or 89.8% of those individuals with early cancer, compared with the current rate of 15%.
Finally, consider the third strategy using the 64 pan-oncology markers of detecting early colorectal cancer (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 64 markers (48 markers for CRC) with average sensitivities of 75%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 95.8%, the first step would identify 4,494,000 individuals (out of 107,000,000 total adults over 50 in the US). This would include, at 99.2% sensitivity, about 40,176 individuals with Stage I colorectal cancer (out of 40,500 individuals with Stage I cancer). However, those 4,494,000 presumptive positive individuals would be evaluated in a second step of 96 markers (48 markers for CRC) with average sensitivities of 66%, requiring a minimum of 5 markers positive. The two-step test would identify 99.2%×98.0%=97.2%=39,372 individuals (out of 40,500 individuals with Stage I cancer) with colorectal cancer. With a specificity of 95.8%, the second test would also generate 4,494,000×4.2%=188,748 false-positives. The positive predictive value of such a test would be 39,372/(188,748+39,372)=17.2%. In other words, 1 in 5.8 individuals who tested positive would actually have Stage I colorectal cancer. In reality, one would need to also include the success for identifying Stage 2 and higher cancers. To be consistent with the idea that as the test is used repeatedly, more of early and less of late CRC will be detected, then an estimate of 40,500 individuals would be identified with Stage I cancer, 40,500 individuals would be identified with Stage II cancer, and the remaining 54,000 individuals would have late-stage cancer=135,000 total individuals with colorectal cancer identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 99.9% would be identified in the first step, of which 99.9%×99.6%=99.5%=40,297 individuals with Stage II cancer would be verified in the second step. For Stage III and IV cancer, 99.9% would be identified in the first step, of which 99.9%×99.9%=99.8%=53,892 individuals with late cancer would be identified. This brings the total identified at 39,372+40,297+53,892=133,561 individuals out of 135,000 with colorectal cancer, for an overall sensitivity of 98.9%. Overall, the positive predictive value of such a test would be 133,561/(188,748+133,561)=41.4%. In other words, 1 in 2.4 individuals who tested positive would actually have colorectal cancer, and this test would identify 79,699/81,000 or 98.4% of those individuals with early cancer, compared with the current rate of 40%.
How would these results vary for using the third strategy (
How would these results vary for using this strategy (
Assuming individual marker false-positive rates of 3%, the first step using 64 markers (36 markers for ovarian) with average sensitivities of 75%, and requiring a minimum of 5 markers positive, then, with an overall specificity of 99.1%, the first step would identify 486,000 individuals (out of 54,000,000 total women ages 50-79 in the U.S.). This would include, at 94.5% sensitivity, about 5,197 individuals with Stage I ovarian cancer (out of 5,500 individuals with Stage I ovarian cancer). However, those 486,000 presumptive positive individuals would be evaluated in a second step of 96 markers (36 markers for ovarian cancer) with average sensitivities of 66%, requiring a minimum of 5 markers positive. The two-step test would identify 94.5%×90.0%=85%=4,675 individuals (out of 5,500 individuals with Stage I ovarian cancer) with ovarian cancer. With a specificity of 99.1%, the second test would also generate 486,000×0.9%=4,374 false-positives. The positive predictive value of such a test would be 4,675/(4,374+4,675)=51.6%. In other words, 1 in 2 individuals who tested positive would actually have Stage I ovarian cancer. In reality, one would need to also include the success for identifying Stage 2 and higher ovarian cancers. Also, assume all four stages are at 5,500, then 5,500×4=22,000 total individuals with ovarian cancer would be identified per year in the U.S. The above calculation already provided the false-positive rate for the early cancer. For Stage II cancer, 98.3% would be identified in the first step, of which 98.3%×96.2%=94.5%=5,201 individuals with Stage II ovarian cancer would be verified in the second step. For Stage III and IV ovarian cancer, 99.7% would be identified in the first step, of which 99.7%×99.2%=98.9%=10,879 individuals with late ovarian cancer would be identified. This brings the total identified at 4,675+5,201+10,879=20,755 individuals out of 22,000 with ovarian cancer, for an overall sensitivity of 94.3%. Overall, the positive predictive value of such a test would be 20,755/(20,755+4,374)=82.6%. In other words, 4 in 5 women who tested positive would actually have ovarian cancer, and this test would identify 9,876/11,000 or 89.8% of those individuals with early cancer, compared with the current rate of 15%.
The aforementioned 5 groups of 48 markers, with average sensitivity of 75%, were designed to also be used to monitor treatment (see
The aforementioned 5 groups of 48 markers were designed to also be used to monitor for recurrence (see
The biology of each cancer is different, and thus the observed sensitivity and specificity for detecting early cancer, monitoring treatment, and detecting early recurrence may be higher or lower from the idealized calculations described herein.
HT-29 colon adenocarcinoma cells are seeded in 60 cm2 culture dishes in McCoy's 5A medium containing 4.5 g/l glucose, supplemented with 10% fetal calf serum, and cultured in a humidified atmosphere containing 5% CO2. Once cells reach 80-90% confluence, they are washed in Phosphate Buffered Saline (×3), and collected by centrifugation (500×g). Genomic DNA is isolated using the DNeasy Blood & Tissue Kit (Qiagen; Valencia, Calif.), and its concentration is measured using Quant-iT Pico green Assay (Life Technologies/Thermo-Fisher; Waltham, Mass.).
High molecular weight (>50 kb) genomic DNA (0.2 mg/ml) is isolated from human blood (buffy coat) (Roche human genomic DNA) and is purchased from Roche (Indianapolis, Ind.). Its concentration is similarly determined using Quant-iT PicoGreen dsDNA Assay Kit.
Cell free DNA is isolated from 5 ml plasma sample (with K2EDTA additive as anti-coagulant) using the QIA amp Circulating Nucleic Acid Kit according to manufacturer's instructions, and quantified using Quant-iT Pico Green Assay (Life Technologies/ThermoFisher; Waltham, Mass.).
Genomic DNA is fragmented through a non random sonication method, using Covaris ultra sonicator (Woburn, Mass.). The quality of the sheared DNA fragments (length range from 50 to 1 kb base pairs) is assessed with Agilent Bioanalyzer system. DNA fragments containing methylated CpGs are captured by methylation-specific antibodies, using the EpiMark® Methylated DNA Enrichment Kit according to manufacturer's instructions (New England Biolabs; Ipswich, Mass.).
PCR primers and LDR probes. All primers to be used in the various categories are listed in the Tables below. Primers are purchased from Integrated DNA Technologies Inc. (IDT) (Coralville, Iowa). Primers designed for use in Step 1 of the 96-marker assay, with average sensitivities of 50%, detect solid tumors are listed in Table 40 below. Primers designed for use in Step 2 of the Group 1-64-marker assay, with average sensitivities of 50%, to detect and identify colorectal, stomach, and esophageal cancers are listed in Table 47 below. Primers designed for use in Step 2 of the Group 2-48-64-marker assay, with average sensitivities of 50%, to detect and identify breast, endometrial, ovarian, cervical, and uterine cancers are listed in Table 48 below. Primers designed for use in Step 2 of the Group 3-48-64-marker assay, with average sensitivities of 50%, to detect and identify lung adenocarcinomas, lung squamous cell carcinoma, and head & neck cancers are listed in Table 49 below. Primers designed for use in Step 2 of the Group 4-36-48-marker assay, with average sensitivities of 50%, to detect and identify prostate and bladder cancers are listed in Table 50 below. Primers designed for use in Step 2 of the Group 5-48-64-marker assay, with average sensitivities of 50%, to detect and identify liver, pancreatic, and gall-bladder cancers are listed in Table 51 below.
500 ng HT29 cell line genomic DNA is treated with ten-eleven translocation (TET1) dioxygenase and pyridine-borane for conversion of 5mC (5-methyl cytosine) and 5hmC (5-hydroxy-methyl cytosine) to DHU (dihydrouracil) generally as described by Liu et al., “Bisulfite-Free Direct Detection of 5-methylcytosine and 5-hydroxymethylcytosine at Base Resolution,” Nat Biotechnol. 37:424-429 (2019), which is hereby incorporated by reference in its entirety.
The desired cancer gene primers and probes (listed in Table 24) are available from Integrated DNA Technologies Inc. (IDT) (Coralville, Iowa).
A 130 μl-volume PCR reaction is set up as follows: 23.14 μl of nuclease free water (IDT), 26 μl of GoTaq Flexi buffer 5× without Magnesium (Pro-mega, Madison, Wis.), 10.4 μl of MgCl2 at 25 mM (Promega, Madison, Wis.), 2.6 μl of dNTPs (10 mM each of dATP, dCTP, dGTP and dUTP) (Promega, Madison, Wis.), 3.25 μl of desired cancer gene forward primer at 2 μM, 3.25 μl of desired cancer gene reverse primer at 2 μM, 3.25 μl of RNAseH2 (IDT) at 20 mU/μl, 2.86 μl of Klentaq1 polymerase (DNA Polymerase Technology, St. Louis, Mo.) mixed with Plantinim Taq Antibody (Invitrogen, Carlsbad, Calif.) (the mixture is prepared by adding 0.3 μl of Klentaq1 polymerase at 50 U/μl to 3 μl of Platinum Taq Antibody at 5 U/μl), and 39 μl of corresponding template.
Each 130 μl PCR mixture is divided into 12 aliquots (tubes or wells), 10 μl each, and then the PCR reactions are run in a Proflex PCR system thermo-cycler (Applied Biosystems/ThermoFisher; Waltham, Mass.) with the following program: 2 min at 95° C., 35 cycles of (10 sec at 94° C., 30 sec at 60° C., and 30 sec at 72° C.), 10 min at 99.5° C., and a final hold at 4° C.
The LDR step is performed in a 10 μl reaction prepared by adding: 5.82 μl of nuclease free water (IDT), 1 μl of 10×AK16D ligase reaction buffer (1× buffer contains 20 mM Tris-HCl at pH 8.5 (Bio-Rad, Hercules, Calif.), 5 mM MgCl2 (Sigma-Aldrich, St. Louis, Mo.), 50 mM KCl (Sigma-Aldrich), 10 mM DTT (Sigma-Aldrich) and 20 μg/ml of BSA (Sigma-Aldrich)), 0.25 μl of DTT (Sigma-Aldrich) at 40 mM, 0.25 μl of NAD (Sigma-Aldrich) at 40 mM, 0.25 μl of RNAseH2 (IDT) at 20 mU/μl, 0.2 μl of desired cancer gene upstream LDR probe at 500 nM, 0.2 μl of desired cancer gene downstream LDR probe at 500 nM, 0.028 μl of purified AK16D ligase at 8.8 μM, and 2 μl of PCR reaction. LDR reactions are run in a Proflex PCR system thermocycler (Applied Biosystems) with the following program: 20 cycles of (10 sec at 94° C., and 4 min at 60° C.) followed by a final infinite hold at 4° C.
The qPCR step is performed in a 10 μl of reaction mixture prepared by adding: 1.5 μl of nuclease free water (IDT), 5 μl of 2× TaqMan® Fast Universal PCR Master Mix (consists of Amplitaq, UDG and dUTP) from Applied Biosystems (Life Technologies, Grand Island, N.Y.), 1 μl of desired cancer gene Tag forward primer at 2.5 μM, 1 μl of desired cancer gene Tag reverse primer at 2.5 μM, 0.5 μl of desired cancer gene Taqman™ probe at 5 μM, and 1 μl of LDR reaction products. The qPCR reactions are run in a ViiA7 real-time thermo-cycler from Applied Biosystems (Life Technologies, Grand Island, N.Y.), using MicroAmp® Fast-96-Well Reaction 0.1 ml plates sealed with MicroAmp™ Optical adhesive film (Applied Biosystems), with the following settings: fast block, Standard curve as experiment type, ROX as passive reference, Ct as quantification method (automatic threshold, but adjusted to 0.05 when needed), TAMRA as reporter, and NFQ-MGB as quencher. The program is set at: 2 min at 50° C., and 40 cycles of (1 sec at 95° C., and 20 sec at 60° C.).
500 ng HT29 cell line genomic DNA is treated with ten-eleven translocation (TET1) dioxygenase and pyridine-borane for conversion of 5mC (5-methyl cytosine) and 5hmC (5-hydroxy-methyl cytosine) to DHU (dihydrouracil) generally as described by Liu et al., “Bisulfite-Free Direct Detection of 5-methylcytosine and 5-hydroxymethylcytosine at Base Resolution,” Nat Biotechnol. 37:424-429 (2019), which is hereby incorporated by reference in its entirety.
The desired cancer gene primers and probes (listed in Table 24) are available from Integrated DNA Technologies Inc. (IDT) (Coralville, Iowa).
Linear amplification step. The linear amplification step is performed in a 25 μl of reaction mixture with: 5 μl of Gotaq Flexi buffer 5× without Magnesium (Promega, Madison, Wis.), 2.5 μl of MgCl2 at 25 mM (Promega, Madison, Wis.), 0.5 μl of dNTPs (with dATP, dCTP, dGTP and dTTP, 10 mM each) (Promega, Madison, Wis.), 1.25 μl of 12-plex gene specific one-direction primers (i.e., forward primers; concentration of primer for each gene is 2 μM), 0.625 μl of RNAseH2 (IDT) at 20 mU/μl (diluted in RNAseH2 dilution buffer from IDT), and 0.55 μl of Klentaq1 polymerase (DNA Polymerase Technology, St. Louis, Mo.) mixed with Platinum Taq Antibody (Invitrogen/Thermo Fisher, Waltham, Mass.) (the mixture is prepared by adding 0.02 μl of Klentaq1 polymerase at 50 U/μl to 0.2 μl of Platinum Taq Antibody at 5 U/μl), and 14.5 μl of corresponding Tet1, pyridine-borane converted genomic DNA (out of 50 μl of eluted DNA after conversion). Linear amplification reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/ThermoFisher, Waltham, Mass.) and run with the following program: 2 min at 94° C., 40 cycles of (20 sec at 94° C., 40 sec at 60° C. and 30 sec at 72° C.), a final hold at 4° C. After the reaction, Platinum Taq antibodies are added in the reaction mixture to inhibit the Klentaq DNA polymerase.
PCR reaction. The linear amplification products are equally divided into two parts (2 times 6-plex for 2 times 6 CpG markers). The PCR step is performed in a 20 μl reaction volume; prepared by mixing: 2 μl of 5× Gotaq Flexi buffer without Magnesium (Promega, Madison, Wis.), 1 μl of MgCl2 at 25 mM (Promega, Madison, Wis.), 0.4 μl of dNTPs (with 10 mM each for dATP, dCTP, dGTP and dUTP) (Promega, Madison, Wis.), 1 μl of each of the opposite-strand PCR primer (2 μM concentration), 0.4 μl of Antarctic Thermolabile UDG (1 u/μl) (New England Biolab, Ipswich, Mass.), 0.25 μl of RNAseH2 (IDT) at 20 mU/μl, 0.44 μl of Klentaq1 polymerase (DNA Polymerase Technology, St. Louis, Mo.) mixed with Platinum Taq Antibody (Invitrogen/Thermo Fisher, Waltham, Mass.) (the mixture is prepared by adding 0.02 μl of Klentaq1 polymerase at 50 U/μl to 0.2 μl of Platinum Taq Antibody at 5 U/μl), and 12 μl of corresponding linear amplification products. PCR reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/ThermoFisher, Waltham, Mass.) with the following program: 10 min at 37° C., 40 cycles of (20 sec at 94° C., 40 sec at 60° C. and 30 sec at 72° C.), 10 min at 99.5° C., and a final hold at 4° C.
LDR step. The LDR step is performed in a 20 μl of reaction volume by mixing: 11.6 μl of nuclease free water (IDT), 2 μl of 10× AK16D ligase reaction buffer [1× buffer contains 20 mM Tris-HCl pH 8.5 (Bio-Rad, Hercules, Calif.), 5 mM MgCl2 (Sigma-Aldrich, St. Louis, Mo.), 50 mM KCl (Sigma-Aldrich, St. Louis, Mo.), 10 mM DTT (Sigma-Aldrich, St. Louis, Mo.) and 20 μg/ml of BSA (Sigma-Aldrich, St. Louis, Mo.), 0.5 μl of DTT (Sigma-Aldrich, St. Louis, Mo.) at 40 mM, 0.4 μl of NAD+ (Sigma-Aldrich, St. Louis, Mo.) at 50 mM, 0.5 μl of RNAseH2 (IDT) at 20 mu/μl, 0.4 μl of corresponding 6 plex LDR upstream probes at 500 nM, 0.4 μl of corresponding 6 plex LDR downstream probes at 500 nM, (3 plex for the other LDR reaction), 0.57 μl of purified AK16D ligase at 0.88 μM, and 4 μl of corresponding PCR reaction products from previous step. LDR reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/ThermoFisher; Waltham, Mass.) using the following program: 20 cycles of (10 sec at 94° C., and 4 min at 60° C.) followed by a final hold at 4° C.
qPCR step. Uni-plex qPCR reactions (i.e. each reaction tube contains only the primers and probe specific to a unique CpG site) are performed in a 10 μl reaction mixture containing: 3 μl of nuclease free water (IDT), 5 μl of 2× TaqMan® Fast Universal PCR Master Mix (Fast Amplitaq, UDG and dUTP) from Applied Biosystems (Applied Biosystems/ThermoFisher; Waltham, Mass.), 0.5 μl of mixture of TaqMan™ Assay forward and reverse primers at 5 μM each, 0.5 μl of Taqman™ probe at 5 μM, and 1 μl of corresponding LDR reaction products. The reactions are run in a ViiA7 real-time thermo-cycler from Applied Biosystems (Applied Biosystems/ThermoFisher; Waltham, Mass.), using MicroAmp® Fast-96-Well Reaction 0.1 ml plates sealed with MicroAmp™ Optical adhesive film (Applied Biosystems/ThermoFisher; Waltham, Mass.), with the following setting: fast block, Standard curve as experiment type, ROX as passive reference, Ct as quantification method (automatic threshold, but adjusted to 0.05 when needed), TAMRA as reporter, and NFQ-MGB as quencher. The thermocycler is programmed as follows: 2 min at 50° C., and 45 cycles of (1 sec at 95° C., and 20 sec at 60° C.).
500 ng HT29 cell line genomic DNA is treated with ten-eleven translocation (TET1) dioxygenase and pyridine-borane for conversion of 5mC (5-methyl cytosine) and 5hmC (5-hydroxy-methyl cytosine) to DHU (dihydrouracil) generally as described by Liu et al., “Bisulfite-Free Direct Detection of 5-methylcytosine and 5-hydroxymethylcytosine at Base Resolution,” Nat Biotechnol. 37:424-429 (2019), which is hereby incorporated by reference in its entirety.
The desired cancer gene primers and probes (listed in Table 24) are available from Integrated DNA Technologies Inc. (IDT) (Coralville, Iowa).
Linear amplification step. In a 25 μl of reaction volume, the linear amplification step is performed by mixing: 5 μl of 5× Gotaq Flexi buffer (no Magnesium) (Promega, Madison, Wis.), 2.5 μl of 25 mM MgCl2 (Promega, Madison, Wis.), 0.5 μl of 10 mM dNTPs (dATP, dCTP, dGTP and dTTP) (Promega, Madison, Wis.), 2.5 μl of 20 plex gene specific one direction primers (concentration of each primer is 1 μM), 0.625 μl of 20 mU/μl RNAseH2 (diluted in RNAseH2 dilution buffer from IDT) (IDT), and 0.55 μl of Klentaq1 polymerase (DNA Polymerase Technology, St. Louis, Mo.) mixed with Platinum Taq Antibody (Invitrogen/Thermo Fisher, Waltham, Mass.) (the mixture is prepared by adding 0.02 μl of Klentaq1 polymerase at 50 U/μl to 0.2 μl of Platinum Taq Antibody at 5 U/μl), and 5.0 μl of corresponding TET1, pyridine-boronate converted genomic DNA. The reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/ThermoFisher, Waltham, Mass.) using the following program: 2 min at 94° C., 40 cycles of (20 sec at 94° C., 40 sec at 60° C., and 30 sec at 72° C.), and a final hold at 4° C. Platinum Taq Antibodies are added in the reaction mixture to inhibit the Klentaq DNA polymerase before the next step.
PCR reaction. The linear amplification products are equally divided into two parts. In the 1st part, first 10 plex (out of 20 plex) gene specific other direction primers and other reagents are added, in the 2nd part, the other 10 plex (out of 20 plex) gene specific other direction primers and other reagents are added. Two 10 plex PCR reactions are carried out. The PCR step is performed in a 20 μl of reaction mixture prepared by adding: 2 μl of Gotaq Flexi buffer 5× without Magnesium (Promega, Madison, Wis.), 1 μl of MgCl2 at 25 mM (Promega, Madison, Wis.), 0.4 μl of dNTPs (with dATP, dCTP, dGTP and dUTP, 10 mM each) (Promega, Madison, Wis.), 2 μl of 10 plex (out of 20 plex in linear amplification step) gene specific forward primers at 0.5 μM each. 0.4 μl of Antarctic Thermolabile UDG (1 u/μl) (New England Biolab, Ipswich, Mass.), 0.25 μl of RNAseH2 (IDT) at 20 mU/μl, 0.44 μl of Klentaq1 polymerase (DNA Polymerase Technology, St. Louis, Mo.) mixed with Platinum Taq Antibody (Invitrogen/Thermo Fisher, Waltham, Mass.) (The mixture is prepared by adding 0.02 μl of Klentaq1 polymerase at 50 U/μl to 0.2 μl of Platinum Taq Antibody at 5 U/μl), and 10 μl of corresponding linear amplification products. PCR reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/ThermoFisher, Waltham, Mass.) and using the following program: 10 min at 37° C., 40 cycles of (20 sec at 94° C., 40 sec at 60° C. and 30 sec at 72° C.), 10 min at 99.5° C., and a final hold at 4° C.
LDR step. The LDR step is performed in a 20 μl reaction prepared by combining: 5.82 μl of nuclease free water (IDT), 2 μl of 10× AK16D ligase reaction buffer (lx buffer contains 20 mM Tris-HCl pH 8.5 (Bio-Rad, Hercules, Calif.), 5 mM MgCl2 (Sigma-Aldrich, St. Louis, Mo.), 50 mM KCl (Sigma-Aldrich, St. Louis, Mo.), 10 mM DTT (Sigma-Aldrich, St. Louis, Mo.) and 20 μg/ml of BSA (Sigma-Aldrich, St. Louis, Mo.)), 0.5 μl of 40 mM DTT (Sigma-Aldrich, St. Louis, Mo.), 0.25 μl of 40 mM NAD+ (Sigma-Aldrich, St. Louis, Mo.), 0.5 μl of 20 mU/μl RNAseH2 (IDT), 0.4 μl of corresponding 10 plex LDR upstream probes at 500 nM each, 0.4 μl of corresponding 10 plex LDR downstream probes at 500 nM each, 0.57 μl of purified AK16D ligase (at 0.88 μM), and 4 μl of PCR reaction products from previous step. LDR reactions are run in a ProFlex PCR system thermocycler (Applied Biosystems/Thermo-Fisher; Waltham, Mass.) using the following program: 20 cycles of (10 sec at 94° C., and 4 min at 60° C.) followed by a final hold at 4° C.
qPCR step. The qPCR step is performed in a 10 μl of reaction volume by combining: 1.5 μl of nuclease free water (IDT), 5 μl of 2× TaqMan® Fast Universal PCR Master Mix (Fast amplitaq, UDG and dUTP) from Applied Biosystems (Applied Biosystems/ThermoFisher; Waltham, Mass.), 1 μl of 2.5 μM TaqMan™ Assay forward primer, 1 μl of 2.504 Taqman™ reverse primer, 0.5 μl of 5 μM Taqman™ probe, and 1 μl of LDR reaction products. qPCR reactions are run in a ViiA7 real-time thermo-cycler from Applied Biosystems (Applied Biosystems/Thermo-Fisher; Waltham, Mass.), using MicroAmp® Fast-96-Well Reaction 0.1 ml plates sealed with MicroAmp™ Optical adhesive film (Applied Biosystems/ThermoFisher; Waltham, Mass.), with the following setting: fast block, Standard curve as experiment type, ROX as passive reference, Ct as quantification method (automatic threshold, but adjusted to 0.05 when needed), TAMRA as reporter, and NFQ-MGB as quencher. The program employed was: 2 min at 50° C., and 45 cycles of (1 sec at 95° C., and 20 sec at 60° C.).
Human plasma (with K2-EDTA as an anti-coagulant) samples are purchased from a vendor. Cell free DNA is isolated from individual plasma samples (5 mL) using the QIA amp Circulating Nucleic Acid Kit (Qiagen) according to manufacturer's instructions, and quantified with Quant-iT Pico Green Assay Life Technologies/Thermo-Fisher; Waltham, Mass.). The linear amplification, PCR, LDR and qPCR steps are carried out as described in Example 3.
Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the present application and these are therefore considered to be within the scope of the present application as defined in the claims which follow.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/843,083, filed May 3, 2019, which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/031118 | 5/1/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62843083 | May 2019 | US |
