SAMPLING DEVICE AND ANALYSIS OF METHYLATED DNA

Abstract
The invention relates to cell sampling devices. In particular, the present invention relates to ingestible cell sampling devices for sampling cells in a subject, and methods of use for detecting abnormalities in a subject using the same. Provided herein is technology for neoplasia screening, and particularly, but not exclusively, to methods, compositions, and related uses for detecting the presence of cancer.
Description
SEQUENCE LISTING

The text of the computer readable sequence listing filed herewith, titled “39463-202_SEQUENCE_LISTING_ST25”, created Apr. 16, 2021, having a file size of 41,366 bytes, is hereby incorporated by reference in its entirety.


FIELD OF THE INVENTION

The invention relates to cell sampling devices. In particular, the present invention relates to ingestible cell sampling devices for sampling cells in a subject, and methods of use for detecting abnormalities in a subject using the same. Provided herein is technology relating to detecting neoplasia and particularly, but not exclusively, to methods, compositions, and related uses for detecting neoplasms such as cancer.


BACKGROUND OF THE INVENTION

To diagnose certain diseases of the gastrointestinal tract, an ingestible cell sampling device may be used to collect cells from the surface of the gastrointestinal tract of a patient. However, various issues exist with the cell sampling devices currently used, including difficulty or unpleasantness in swallowing and retrieving the device. For sample collection using an ingestible device that is retrieved by withdrawal from the mouth, issues include detachment of the sponge from the string during use, and/or laceration to the esophagus of the patient upon withdrawal of the device. Accordingly, what is needed are improved ingestible cell sampling devices for use in a subject.


An emerging approach to cancer screening involves the assay of tumor-specific DNA alterations in bodily samples from cancer patients, such as stool, serum, and urine (Osborn N K, Ahlquist D A. Gastroenterology 2005; 128:192-206; Ahlquist DA, et al., Gastroenterology 2000; 119:1219-27; Ahlquist D A, et al., Gastroenterology 2002; 122:Suppl A40; Chen W D, et al., J Natl Cancer Inst 2005; 97:1124-32; Zou H, et al., Cancer Epidemiol Biomarkers Prey 2006; 15:1115-9; Zou H Z, Clin Cancer Res 2002; 8:188-91; Hoque M O, J Clin Oncol 2005; 23:6569-75; Belinsky S A, et al., Cancer Res 2006; 66:3338-44; Itzkowitz S H, et al., Clin Gastroenterol Hepatol 2007; 5:111-7′ Kann L, et al., Clin Chem 2006; 52:2299-302). It is important to select markers with high accuracy if efficiency and effectiveness are to be achieved in a cancer screening application. Due to the molecular heterogeneity of gastrointestinal neoplasias, high detection rates often require a panel of markers. More accurate, user-friendly, and widely distributable tools to improve screening effectiveness, acceptability, and access are needed.


SUMMARY OF THE INVENTION

In some aspects, provided herein are ingestible cell sampling devices. The device comprises an abrasive sponge housed within a dissolvable capsule, a molded cap, and a string attached to the molded cap. In some embodiments, the abrasive sponge comprises reticulated foam. In some embodiments, the abrasive sponge is compressible. The sponge may be retained in a compressed state by the dissolvable capsule. In some embodiments, the abrasive sponge, when in an uncompressed state, has a shape configured to maximize an exterior dimension while minimizing the total amount of sponge to be contained in a capsule. For example, in some embodiments, the abrasive sponge is formed to have concavities or indentations, and/or to have a void space, as may be provided by removing at least one portion of the abrasive sponge prior to compressing the sponge into the dissolvable capsule, e.g., from inside the sponge, and/or from the top, bottom, and/or side of the abrasive sponge.


In some embodiments, the dissolvable capsule comprises one or more openings, such that a portion of the abrasive sponge is exposed to the external environment at the one or more openings. In some embodiments, the dissolvable capsule comprises a first closed end and a second closed end. In alternative embodiments, the dissolvable capsule comprises a first closed end and a second open end.


In some embodiments, the molded cap comprises an internal surface in contact with an external surface of one end of the capsule and an exterior surface in contact with the external environment. In some embodiments, the molded cap comprises an internal surface in contact with the abrasive sponge and an exterior surface in contact with the external environment. In some embodiments, the molded cap comprises an interior surface in contact with the abrasive sponge and an exterior surface. The exterior surface of the molded cap may be in contact with an internal surface of one end of the capsule. In some embodiments, the interior surface of the molded cap is attached to the abrasive sponge by an adhesive, which is preferably dissolvable.


In some embodiments, the string is attached to the molded cap by a knot. The string may comprise a suture. In some embodiments, the string passes through a portion of the abrasive sponge.


In some aspects, provided herein are methods of obtaining a cell sample from a subject. In some embodiments, a method of obtaining a cell sample from a subject comprises providing the ingestible cell sampling device described herein to the subject, and removing the ingestible cell sampling device from the subject. The ingestible cell sampling device may be removed from the subject within 10 minutes of providing the ingestible cell sampling device to the subject.


In some embodiments, the technology provides an ingestible cell sampling device and systems comprising such a device, e.g., for conducting a cell sampling method using a device as described herein.


Embodiments of the technology include:

  • 1. An ingestible cell sampling device comprising:
    • i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule.;
    • ii) a molded cap comprising a cap interior surface and a cap exterior surface; and
    • iii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge.
  • 2. The ingestible cell sampling device of embodiment 1, further comprising an unswallowable handle attached to the string.
  • 3. The ingestible cell sampling device of embodiment 2, wherein the string has a second end, wherein the unswallowable handle is attached to the string at the second end.
  • 4. The ingestible cell sampling device of embodiment 1, wherein the dissolvable capsule comprises one or more openings, wherein a portion of the abrasive sponge is exposed to the external environment at the one or more openings.
  • 5. The ingestible cell sampling device of embodiment 1, wherein the dissolvable capsule comprises a first end and a second end, wherein:
    • a) the first end is closed and the second end is closed; or
    • b) the first end is closed and the second end is open.
  • 6. The ingestible cell sampling device of embodiment 5, wherein the cap interior surface is in contact with the exterior surface of the capsule at the first closed end, and the cap exterior surface is in contact with the external environment.
  • 7. The ingestible cell sampling device of embodimentl, wherein the cap interior surface is in contact with the abrasive sponge.
  • 8. The ingestible cell sampling device of embodiment 7, wherein the cap exterior surface is in contact with an internal surface of the capsule at the first closed end and/or with the external environment.
  • 9. The ingestible cell sampling device of embodiment 7, wherein the cap interior surface is attached to the abrasive sponge by an adhesive.
  • 10. The ingestible cell sampling device of embodiment 1, wherein the cap interior surface is attached to the abrasive sponge.
  • 11. The ingestible cell sampling device of embodiment 1, wherein the string is attached to the molded cap by a knot and/or an adhesive.
  • 12. A system or kit for obtaining a cell sample from a subject, comprising an ingestible cell sampling device of embodiment 1; and further comprising one or more of:
    • i) a container to receive an abrasive sponge comprising collected cells;
    • ii) a cell preservative reagent, preferably a buffer reagent;
    • iii) a microscope slide;
    • iv) an assay plate;
    • v) a local anesthetic treatment, preferably a local anaesthetic spray;
    • vi) a component of a drinkable solution; preferably a pre-mixed drinkable solution; and
    • vii) a lubricant, preferably a lubricant gel or liquid.
  • 13. A method of obtaining a cell sample from a subject, comprising:
    • a) orally administering an abrasive sponge housed within a dissolvable capsule of a ingestible cell sampling device of to the subject, wherein the ingestible cell sampling device comprises:
      • i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule.;
      • ii) a molded cap comprising a cap interior surface and a cap exterior surface; and
      • iii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge, and
    • b) withdrawing from the subject the abrasive sponge, wherein the abrasive sponge collects a cell sample from the subject during the withdrawing.
  • 14. A method of characterizing an esophageal cell sample from a subject, comprising:


a) preparing DNA from the esophageal cell sample from the subject;


b) treating the DNA with bisulfite to produce bisulfite-treated DNA; and


c) amplifying the bisulfite-treated DNA to determine an amount of at least one methylated biomarker gene selected from the group of methylation biomarker genes consisting of ANKRD13B, BMP3, CD1D, CDKN2A , CHST2, CN1NNM1, D103, DOCK2, DTX1, ELMO1, FER1L4, FERMT3, FLI1, GRIN2D, HUNK, JAM3, LRRC4, NDRG4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, ZNF671, and ZNF682;


d) assaying the bisulfite-treated DNA from the esophageal cell sample for an amount of a reference DNA; and


e) comparing the amount of the at least one methylated biomarker gene to the amount of the reference DNA to determine a methylation state for the at least one methylation biomarker gene in the esophageal cell sample.

  • 15. The method of embodiment 14, comprising obtaining the esophageal cell sample from the subject by a method comprising:
    • a) orally administering an abrasive sponge housed within a dissolvable capsule of a ingestible cell sampling device of to the subject, wherein the ingestible cell sampling device comprises:
      • i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule;
      • ii) a molded cap comprising a cap interior surface and a cap exterior surface; and
      • iii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge and
    • b) withdrawing from the subject the abrasive sponge, wherein the abrasive sponge collects an esophageal cell sample from the subject during the withdrawing.
  • 16. The method of embodiment 14, wherein determining the methylation state for the at least one methylation biomarker gene in the esophageal cell sample comprises determining the methylation state of no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, or 33 methylation biomarker genes selected from the group consisting of ANKRD13B, BMP3, CD1D, CDKN2A , CHST2, CNNM1, D103, DOCK2, DTX1, ELMO1, FER1L4, FERMT3, FLI1, GRIN2D, HUNK, JAM3, LRRC4, NDRG4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, ZNF671, and ZNF682.
  • 17. The method of embodiment 16, wherein the at least one methylated biomarker gene is selected from the group of methylation biomarker genes consisting of: ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671.
  • 18. The method of embodiment 16, wherein the at least one methylated biomarker gene is selected from the group of methylation biomarker genes consisting of: BMP3, NDRG4, VAV3, SFMBT2, D103, HUNK, ELMO1, CD1D, CDKN2A, and OPLAH.
  • 19. The method of embodiment 14, wherein the reference DNA is methylated.
  • 20. The method of embodiment 14, wherein determining the amount of the at least one methylated biomarker gene comprises using one or more methods selected from the group consisting of methylation-specific PCR, quantitative methylation-specific PCR, methylation-sensitive DNA restriction enzyme analysis, quantitative bisulfite pyrosequencing, flap endonuclease assay, PCR-flap assay, and bisulfite genomic sequencing PCR.


In some aspects, provided herein is technology relating to detecting neoplasia and particularly, but not exclusively, to methods, compositions, and related uses for detecting premalignant and malignant colorectal cancer by analysis of blood and/or plasma samples from a subject, e.g., a patient. As the technology is described herein, the section headings used are for organizational purposes only and are not to be construed as limiting the subject matter in any way.


Provided herein is a panel of methylated DNA markers assayed on tissue that achieves extremely high discrimination for colorectal cancer while remaining negative in normal colorectal tissue. This panel can be applied, for example, to blood or bodily fluid-based testing, with applications in colorectal cancer screening.


Markers and/or panels of markers (e.g., a chromosomal region having an annotation selected from ANKRDJ3B, CHST2, CNNMJ, DOCK2, DTX1, FERJL4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLCJ2A8, TBXJ5, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF67J) were identified in studies by comparing the methylation state of DNA markers from colorectal cancer samples to the corresponding markers in normal (non-cancerous) samples.


As described herein, the technology provides a number of methylated DNA markers and subsets thereof (e.g., sets of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 biomarkers, alone or in any combination or subcombination) with high discrimination for colon cancer. Experiments applied a selection filter to candidate markers to identify markers that provide a high signal to noise ratio and a low background level to provide high specificity and selectivity for purposes of cancer screening or diagnosis. For example, as described herein below, a combination of 12 markers and carcinoembryonic antigen (CEA) protein resulted in 67.4% sensitivity (60/89 cancers) for all of the cancer plasma samples tested, with 92.6% specificity.


Accordingly, provided herein is technology related to a method of screening for colon cancer in a sample obtained from a subject, the method comprising assaying an amount of a methylated marker DNA, e.g., to assess a methylation state of a marker in a sample obtained from a subject; and identifying the subject as having colon cancer when the methylation state of the marker is different than a methylation state of the marker assayed in a subject that does not have a neoplasm. In some embodiments, the marker comprises a chromosomal region having an annotation selected from ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671. In some embodiments, the technology comprises assaying a plurality of markers, e.g., comprising assaying 2 to 20, preferably 2-14, more preferably 2-12 markers. For example in some embodiments, the method comprises analysis of the methylation status of two or more markers selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI. In preferred embodiments, the assay comprises detection of CEA protein.


The technology is not limited in the methylation state assessed. In some embodiments assessing the methylation state of the marker in the sample comprises determining the methylation state of one base. In some embodiments, assaying the methylation state of the marker in the sample comprises determining the extent of methylation at a plurality of bases. Moreover, in some embodiments the methylation state of the marker comprises an increased methylation of the marker relative to a normal methylation state of the marker, i.e., relative to the methylation state of the marker in DNA from a subject who does not have a neoplasia. In some embodiments, the methylation state of the marker comprises a decreased methylation of the marker relative to a normal methylation state of the marker. In some embodiments the methylation state of the marker comprises a different pattern of methylation of the marker relative to a normal methylation state of the marker.


In some embodiments, the technology provides a method of generating a record reporting a colon neoplasm in a sample obtained from a subject comprising the steps of:


a) assaying a sample from a subject for an amount of at least one methylated marker gene selected from the group consisting of ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671 in a sample obtained from a subject;


b) assaying said sample for an amount of reference marker in said sample;


c) comparing the amount of said at least one methylated marker gene to the amount of reference marker, preferably a methylated reference marker, in said sample to determine a methylation state for said at least one marker gene in said sample; and


d) generating a record reporting the methylation state for said at least one marker gene in said sample.


The record reporting the methylation state of a marker is not limited to any particular form of report, and may comprise, for example, an update to an electronic medical record, a printed report, or an electronic message. In some embodiments, the laboratory data generated during the assaying is included in the report, while in some embodiments, only a summary of the data or a diagnostic result based on the determined methylation state for the at least one marker gene is included in the record.


In some embodiments, the sample is assayed for at least two of the markers, and preferably the at least one methylated marker gene is selected from the group consisting of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI. In still more preferred embodiments, the sample is assayed for a group of markers comprising of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI. In preferred embodiments, a sample from the subject is assayed for the presence of CEA protein.


In some embodiments the method used for assaying comprises obtaining a sample comprising DNA from a subject, and treating DNA obtained from the sample with a reagent that selectively modifies unmethylated cytosine residues in the obtained DNA to produce modified residues. In preferred embodiments the reagent comprises a bisulfite reagent.


The method is not limited to a particular size of a methylated marker region analyzed, or the number of nucleotides analyzed for methylation status. In some embodiments assaying the methylation state of the marker DNA in the sample comprises determining the methylation state of one base, while in other embodiments the assay comprises determining the extent of methylation at a plurality of bases. In some embodiments the methylation state of the marker comprises an increased or decreased methylation of the marker relative to a normal methylation state of the marker, while in some embodiments the methylation state of the marker comprises a different pattern of methylation, e.g., a different subset of methylated nucleotides in a methylated region of the marker relative to a normal methylation state of the marker.


The technology is not limited to particular sample types. For example, in some embodiments the sample is a tissue sample, a blood sample, a serum sample, or a sputum sample. In certain embodiments a tissue sample comprises colon tissue.


The technology is not limited to any particular method of assaying DNA samples. For example, in on some embodiments the assaying comprises using polymerase chain reaction, nucleic acid sequencing, mass spectrometry, methylation specific nuclease, mass-based separation, and/or target capture. In certain preferred embodiments the assaying comprises using a flap endonuclease assay. In particularly preferred embodiments the sample DNA and/or reference marker DNA are bisulfite-converted and the assay for determining the methylation level of the DNA is achieved by a technique comprising the use of methylation-specific PCR, quantitative methylation-specific PCR, methylation-sensitive DNA restriction enzyme analysis, quantitative bisulfite pyrosequencing, PCR-flap assay, flap endonuclease assay, and/or bisulfite genomic sequencing PCR.


In some embodiments, an oligonucleotide in said mixture comprises a reporter molecule, and in preferred embodiments, the reporter molecule comprises a fluorophore. In some embodiments the oligonucleotide comprises a flap sequence. In some embodiments the mixture further comprises one or more of a FRET cassette; a FEN-1 endonuclease and a thermostable DNA polymerase, preferably a bacterial DNA polymerase.


In some embodiments, the technology used comprises detecting multiple markers and/or multiple regions of a single marker using an assay that reports detection of the multiple markers and/or multiple regions of a single marker to a single signal output, e.g., a single fluorescent dye. For example, in some embodiments, an assay is configured to report the cleavage of flap endonuclease probes specific for multiple different target sites via a single FRET cassette.


In some embodiments, then, the assaying of a sample comprises preparing a reaction mixture comprising amplification reagents for amplifying at least two methylated marker DNAs, and flap cleavage reagents for performing a flap endonuclease assay on amplified marker DNAs, wherein said reagents comprise:

    • i) a first primer pair for producing a first amplified region of a methylated marker DNA;
    • ii) a first probe comprising a) a sequence complementary to at least a portion of said first amplified region a methylated marker DNA; and b) a flap portion having a first flap sequence that is not substantially complementary to said first amplified region of a methylated marker DNA;
    • iii) a second primer pair for producing a second amplified region of a methylated marker DNA;
    • iv) a second probe comprising a) a sequence complementary to at least a portion of said second region of a methylated marker DNA; and b) a flap portion having said first flap sequence, wherein said first flap sequence is not substantially complementary to said second amplified region of a methylated marker DNA;
    • v) a DNA polymerase; and
    • vi) a flap endonuclease.


In some embodiments, said first amplified region of a methylated marker DNA and said second amplified region of a methylated marker DNA are amplified from different regions of the same methylation marker gene, while in other embodiments, the first amplified region of a methylated marker DNA and the second amplified region of a methylated marker DNA are amplified from different methylation marker genes. In some preferred embodiments, amplifying the at least two methylated marker DNAs comprises amplifying at least two methylated marker DNAs selected from the group consisting of ANKRD13B, BMP3, CD1D, CDKN2A , CHST2, CNNM1, DIO3, DOCK2, DTX1, ELMO1, FER1L4, FERMT3, FLI1, GRIN2D, HUNK, JAM3, LRRC4, NDRG4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, ZNF671, and ZNF682.


In preferred embodiments, amplifying the at least two methylated marker DNAs comprises amplifying at least three methylated marker DNAs. In such embodiments, the reagents may preferably comprise a third primer pair for producing a third amplified region of a methylated marker DNA; and a third probe comprising a) a sequence complementary to at least a portion of the third amplified region of a methylated marker DNA; and b) a flap portion having the same first flap sequence, wherein the first flap sequence is not substantially complementary to the third amplified region of a methylated DNA.


In some embodiments, a reference nucleic acid is also assayed. In such embodiments, the reagents may further comprise a reference primer pair for producing an amplified region of the reference nucleic acid, and a reference probe comprising a) a sequence complementary to at least a portion of the amplified region of the reference nucleic acid; and b) a flap portion having a second flap sequence, wherein the second flap sequence is not substantially complementary to the amplified region of a reference nucleic acid or to the first FRET cassette; and a second FRET cassette comprising a sequence complementary to the second flap sequence.


The technology for detecting multiple nucleic acid sequences (e.g., multiple markers and/or multiple regions of a single marker) using an assay that reports detection of the multiple markers and/or multiple regions of a single marker to a single signal output, e.g., a single fluorescent dye, is not limited to analysis of methylation, or to detection or assaying of the sample types or markers discussed above. For example, in some embodiments the technology provides a method of characterizing any sample (e.g., from a subject) comprising detecting at least one target nucleic acid in a sample, wherein said detecting said at least one target nucleic acid in the sample comprises preparing a reaction mixture comprising amplification reagents for producing at least two different amplified DNAs, and flap cleavage reagents for performing a flap endonuclease assay on the at least two different amplified DNAs, wherein said reagents comprise:

    • i) a first primer pair for producing a first amplified DNA ;
    • ii) a first probe comprising a) a sequence complementary to a region of said first amplified DNA; and b) a flap portion having a first flap sequence that is not substantially complementary to said first amplified DNA;
    • iii) a second primer pair for producing a second amplified DNA;
    • iv) a second probe comprising a) a sequence complementary to a region of said second amplified DNA; and b) a flap portion having said first flap sequence, wherein said first flap sequence is not substantially complementary to said second amplified DNA;
    • v) a FRET cassette comprising a sequence complementary to said first flap sequence;
    • vi) a DNA polymerase; and
    • vii)a flap endonuclease.


In some embodiments, the at least two different target DNAs may comprise at least two different marker genes or marker regions in said sample, while in some embodiments, the at least two different target DNAs comprise at least two different regions of a single marker gene in the sample. The nucleic acids that can be analyzed using the methods disclosed herein are not limited to any particular type of nucleic acid, and may comprise any nucleic acid that can serve as a target for in vitro amplification, e.g., by PCR. In some embodiments, one or more of the at least one target nucleic acid in the sample is RNA. As discussed above, the method is not limited to analyzing two markers or regions, but may be applied to, for example, three, four, five, six, seven, etc. target sequences that report to the same FRET cassette. Further, assays may be combined so that multiple different target nucleic acids in an assay report to a first FRET cassette, multiple different targets in the same assay report to a second FRET cassette, multiple different targets in the same assay report to a third FRET cassette, etc.


The technology also provides kits. For example, in some embodiments a kit comprises a first primer pair for producing a first amplified DNA; a first probe comprising a) a sequence complementary to a region of said first amplified DNA; and b) a flap portion having a first flap sequence that is not substantially complementary to said first amplified DNA; a second primer pair for producing a second amplified DNA; a second probe comprising a) a sequence complementary to a region of said second amplified DNA; and b) a flap portion having said first flap sequence, wherein said first flap sequence is not substantially complementary to said second amplified DNA; a FRET cassette comprising a sequence complementary to said first flap sequence; a DNA polymerase; and a flap endonuclease.


In certain preferred embodiments the technology provides a kit, comprising a) at least one oligonucleotide, wherein at least a portion of the oligonucleotide specifically hybridizes to a marker selected from the group consisting of ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671, and b) at least one additional oligonucleotide, wherein at least a portion of the additional oligonucleotide specifically hybridizes to a reference nucleic acid. In preferred embodiments, the kit comprises an assay for detecting CEA protein. In some embodiments the kit comprises at least two additional oligonucleotides and, in some embodiments, the kit further comprises a bisulfite reagent.


In certain embodiments at least a portion of the oligonucleotide specifically hybridizes to a least one the marker selected from the group consisting of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI. In preferred embodiments, the kit comprises at least 12 oligonucleotides, wherein each of the markers in the group consisting of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI specifically hybridizes to at least one of the 12 oligonucleotides.


In preferred embodiments, oligonucleotide(s) provided in a kit are selected from one or more of a capture oligonucleotide, a pair of nucleic acid primers, a nucleic acid probe, and an invasive oligonucleotide.


In some embodiments any one of the kits describe above further comprises a solid support, such as a magnetic bead or particle. In preferred embodiments, a solid support comprises one or more capture reagents, e.g., oligonucleotides complementary said one or more markers genes.


The technology also provides compositions. For example, in some embodiments the technology provides a composition comprising a mixture, e.g., a reaction mixture, that comprises a first primer pair for producing a first amplified DNA; a first probe comprising a) a sequence complementary to a region of the first amplified DNA; and b) a flap portion having a first flap sequence that is not substantially complementary to the first amplified DNA; a second primer pair for producing a second amplified DNA; a second probe comprising a) a sequence complementary to a region of the second amplified DNA; and b) a flap portion having said first flap sequence, wherein the first flap sequence is not substantially complementary to the second amplified DNA; a FRET cassette comprising a sequence complementary to said first flap sequence; a DNA polymerase; and a flap endonuclease. In preferred embodiments, the composition further comprises the first amplified DNA and the second amplified DNA, wherein the first probe is not substantially complementary to the second amplified DNA, and wherein the second probe is not substantially complementary to the first amplified DNA. In some embodiments, the composition comprises a primer or a probe complexed to a DNA.


In some embodiments, the composition comprises a complex of a target nucleic acid selected from the group consisting of ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671, and an oligonucleotide that specifically hybridizes to the target nucleic acid. In preferred embodiments, the mixture comprises a complex of a target nucleic acid selected from the group consisting of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI and an oligonucleotide that specifically hybridizes to the target nucleic acid. Oligonucleotides in the mixture include but are not limited to one or more of a capture oligonucleotide, a pair of nucleic acid primers, a hybridization probe, a hydrolysis probe, a flap assay probe, and an invasive oligonucleotide.


In some embodiments, the target nucleic acid in the mixture comprises a nucleic acid sequence selected from the group consisting of SEQ ID NOS: 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96, 101, 106, 111, 121, 126, 131, and 136.


In some embodiments, the mixture comprises bisulfite-converted target nucleic acid that comprises a nucleic acid sequence selected from the group consisting of SEQ ID NOS:2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57, 62, 67, 72, 77, 82, 87, 92, 97, 102, 107, 112, 122, 127, 132, and 137.


DEFINITIONS

To facilitate an understanding of the present technology, a number of terms and phrases are defined below. Additional definitions are set forth throughout the detailed description.


Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the technology may be readily combined, without departing from the scope or spirit of the technology.


In addition, as used herein, the term “or” is an inclusive “or” operator and is equivalent to the term “and/or” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a”, “an”, and “the” include plural references. The meaning of “in” includes “in” and “on.”


The transitional phrase “consisting essentially of” as used in claims in the present application limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention, as discussed in In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA 1976). For example, a composition “consisting essentially of” recited elements may contain an unrecited contaminant at a level such that, though present, the contaminant does not alter the function of the recited composition as compared to a pure composition, i.e., a composition “consisting of” the recited components.


The term “abrasive” as used herein refers to a material capable of removing cells from a surface, and preferably collecting the cells removed from the surface. For example, abrasive may indicate a material capable of removing cells from the esophagus of a subject. Preferably, an abrasive material is capable of removing cells from a surface (e.g., the esophagus) without causing damage to the esophagus.


The term “dissolvable” as used herein refers to a material capable of dissolving when exposed to the environment within the stomach cavity. The term “esophageal disorder” refers to types of disorder associated with the esophagus and/or esophageal tissue. Examples of esophageal disorders include, but are not limited to, Barrett's esophagus (BE), Barrett's esophageal dysplasia (BED), Barrett's esophageal low-grade dysplasia (BE-LGD), Barrett's esophageal high-grade dysplasia (BE-HGD), and esophageal adenocarcinoma (EAC).


The term “molded” as used herein means any suitable means of fabricating a component, e.g., a cap or capsule, including but not limited to injection molding, compression molding, transfer molding, sintering, various means of 3-D additive printing, stereolithography, and machining.


The term “capsule” as used herein refers to any component or material serving to surround or encase a sponge, preferably in a manner that renders the sponge swallowable. In some embodiments, the capsule is dissolvable. A capsule encompasses any material or device that encloses a sponge, preferably a sponge in a compressed state, and that provides an surface suitable for swallowing, e.g., a surface of sufficient smoothness and/or slickness to facilitate swallowing of the sponge. A capsule may be formed separately, e.g., as a molded empty container in which a sponge is later partially or completely enclosed, or a capsule may be formed as part of process of encasing the sponge, e.g., as a coating, wrapping, or other binding treatment applied during or after compression of the sponge, and having the effect of holding the enclosed sponge in the compressed state.


The term “button” as used herein in reference to an ingestible sampling device refers to a rigid or semi-rigid component attached or attachable at or near an end of a string of the ingestible sampling device, preferably comprising one or more holes or openings for attachment of the string, e.g., with a loop or knot, preferably having a disk-like shape.


The term “string” as used herein refers broadly to any cord, thread, filament, cable, strand, fiber, ribbon, webbing, suture, lacing, or other flexible tethering material, including materials that are a single filament, and that comprise multiple filaments, e.g., comprising one or more strands that are, for example, twisted, braided, woven, fused, or otherwise combined to form a string, and may comprise strands or filaments of the same or different natural, synthetic, or hybrid material, e.g., silk, cotton, polyester, nylon, polypropylene, cellulose, and the like. A string or individual filaments of a string may be solid, e.g., a single cord or filament of a flexible material such as nylon or polypropylene, or a string may comprise one or more hollow strands, e.g., a tubing of nylon, polypropylene, or other flexible material. A string may comprise one or more informative markings, e.g., calibration markings indicating, for example, a distance between a marking and an end of the string. A series of calibration markings may be provided along the string, and may be at evenly spaced intervals, or at intervals of different lengths. The term “reticulated” as used herein refers to a porous, low density material, e.g., a foam. Reticulated material comprises open pores or cells, with few intact closed cells.


As used herein, “methylation” refers to cytosine methylation at positions C5 or N4 of cytosine, the N6 position of adenine, or other types of nucleic acid methylation. In vitro amplified DNA is usually unmethylated because typical in vitro DNA amplification methods do not retain the methylation pattern of the amplification template. However, “unmethylated DNA” or “methylated DNA” can also refer to amplified DNA whose original template was unmethylated or methylated, respectively.


Accordingly, as used herein a “methylated nucleotide” or a “methylated nucleotide base” refers to the presence of a methyl moiety on a nucleotide base, where the methyl moiety is not present in a recognized typical nucleotide base. For example, cytosine does not contain a methyl moiety on its pyrimidine ring, but 5-methylcytosine contains a methyl moiety at position 5 of its pyrimidine ring. Therefore, cytosine is not a methylated nucleotide and 5-methylcytosine is a methylated nucleotide. In another example, thymine contains a methyl moiety at position 5 of its pyrimidine ring; however, for purposes herein, thymine is not considered a methylated nucleotide when present in DNA since thymine is a typical nucleotide base of DNA.


As used herein, a “methylated nucleic acid molecule” refers to a nucleic acid molecule that contains one or more methylated nucleotides.


As used herein, a “methylation state”, “methylation profile”, and “methylation status” of a nucleic acid molecule refers to the presence of absence of one or more methylated nucleotide bases in the nucleic acid molecule. For example, a nucleic acid molecule containing a methylated cytosine is considered methylated (e.g., the methylation state of the nucleic acid molecule is methylated). A nucleic acid molecule that does not contain any methylated nucleotides is considered unmethylated.


The methylation state of a particular nucleic acid sequence (e.g., a gene marker or DNA region as described herein) can indicate the methylation state of every base in the sequence or can indicate the methylation state of a subset of the bases (e.g., of one or more cytosines) within the sequence, or can indicate information regarding regional methylation density within the sequence with or without providing precise information of the locations within the sequence the methylation occurs.


The methylation state of a nucleotide locus in a nucleic acid molecule refers to the presence or absence of a methylated nucleotide at a particular locus in the nucleic acid molecule. For example, the methylation state of a cytosine at the 7th nucleotide in a nucleic acid molecule is methylated when the nucleotide present at the 7th nucleotide in the nucleic acid molecule is 5-methylcytosine. Similarly, the methylation state of a cytosine at the 7th nucleotide in a nucleic acid molecule is unmethylated when the nucleotide present at the 7th nucleotide in the nucleic acid molecule is cytosine (and not 5-methylcytosine).


The methylation status can optionally be represented or indicated by a “methylation value” (e.g., representing a methylation frequency, fraction, ratio, percent, etc.) A methylation value can be generated, for example, by quantifying the amount of intact nucleic acid present following restriction digestion with a methylation dependent restriction enzyme or by comparing amplification profiles after bisulfite reaction or by comparing sequences of bisulfite-treated and untreated nucleic acids. Accordingly, a value, e.g., a methylation value, represents the methylation status and can thus be used as a quantitative indicator of methylation status across multiple copies of a locus. This is of particular use when it is desirable to compare the methylation status of a sequence in a sample to a threshold or reference value.


As used herein, “methylation frequency” or “methylation percent (%)” refer to the number of instances in which a molecule or locus is methylated relative to the number of instances the molecule or locus is unmethylated.


As such, the methylation state describes the state of methylation of a nucleic acid (e.g., a genomic sequence). In addition, the methylation state refers to the characteristics of a nucleic acid segment at a particular genomic locus relevant to methylation. Such characteristics include, but are not limited to, whether any of the cytosine (C) residues within this DNA sequence are methylated, the location of methylated C residue(s), the frequency or percentage of methylated C throughout any particular region of a nucleic acid, and allelic differences in methylation due to, e.g., difference in the origin of the alleles. The terms “methylation state”, “methylation profile”, and “methylation status” also refer to the relative concentration, absolute concentration, or pattern of methylated C or unmethylated C throughout any particular region of a nucleic acid in a biological sample. For example, if the cytosine (C) residue(s) within a nucleic acid sequence are methylated it may be referred to as “hypermethylated” or having “increased methylation”, whereas if the cytosine (C) residue(s) within a DNA sequence are not methylated it may be referred to as “hypomethylated” or having “decreased methylation”. Likewise, if the cytosine (C) residue(s) within a nucleic acid sequence are methylated as compared to another nucleic acid sequence (e.g., from a different region or from a different individual, etc.) that sequence is considered hypermethylated or having increased methylation compared to the other nucleic acid sequence. Alternatively, if the cytosine (C) residue(s) within a DNA sequence are not methylated as compared to another nucleic acid sequence (e.g., from a different region or from a different individual, etc.) that sequence is considered hypomethylated or having decreased methylation compared to the other nucleic acid sequence. Additionally, the term “methylation pattern” as used herein refers to the collective sites of methylated and unmethylated nucleotides over a region of a nucleic acid. Two nucleic acids may have the same or similar methylation frequency or methylation percent but have different methylation patterns when the number of methylated and unmethylated nucleotides are the same or similar throughout the region but the locations of methylated and unmethylated nucleotides are different. Sequences are said to be “differentially methylated” or as having a “difference in methylation” or having a “different methylation state” when they differ in the extent (e.g., one has increased or decreased methylation relative to the other), frequency, or pattern of methylation. The term “differential methylation” refers to a difference in the level or pattern of nucleic acid methylation in a cancer positive sample as compared with the level or pattern of nucleic acid methylation in a cancer negative sample. It may also refer to the difference in levels or patterns between patients who have recurrence of cancer after surgery versus patients who do not have recurrence. Differential methylation and specific levels or patterns of DNA methylation are prognostic and predictive biomarkers, e.g., once the correct cut-off or predictive characteristics have been defined.


Methylation state frequency can be used to describe a population of individuals or a sample from a single individual. For example, a nucleotide locus having a methylation state frequency of 50% is methylated in 50% of instances and unmethylated in 50% of instances. Such a frequency can be used, for example, to describe the degree to which a nucleotide locus or nucleic acid region is methylated in a population of individuals or a collection of nucleic acids. Thus, when methylation in a first population or pool of nucleic acid molecules is different from methylation in a second population or pool of nucleic acid molecules, the methylation state frequency of the first population or pool will be different from the methylation state frequency of the second population or pool. Such a frequency also can be used, for example, to describe the degree to which a nucleotide locus or nucleic acid region is methylated in a single individual. For example, such a frequency can be used to describe the degree to which a group of cells from a tissue sample are methylated or unmethylated at a nucleotide locus or nucleic acid region.


As used herein a “nucleotide locus” refers to the location of a nucleotide in a nucleic acid molecule. A nucleotide locus of a methylated nucleotide refers to the location of a methylated nucleotide in a nucleic acid molecule.


Typically, methylation of human DNA occurs on a dinucleotide sequence including an adjacent guanine and cytosine where the cytosine is located 5′ of the guanine (also termed CpG dinucleotide sequences). Most cytosines within the CpG dinucleotides are methylated in the human genome, however some remain unmethylated in specific CpG dinucleotide rich genomic regions, known as CpG islands (see, e.g., Antequera et al. (1990) Cell 62: 503-514).


As used herein, a “CpG island” refers to a G:C-rich region of genomic DNA containing an increased number of CpG dinucleotides relative to total genomic DNA. A CpG island can be at least 100, 200, or more base pairs in length, where the G:C content of the region is at least 50% and the ratio of observed CpG frequency over expected frequency is 0.6; in some instances, a CpG island can be at least 500 base pairs in length, where the G:C content of the region is at least 55%) and the ratio of observed CpG frequency over expected frequency is 0.65. The observed CpG frequency over expected frequency can be calculated according to the method provided in Gardiner-Garden et al (1987) J. Mol. Biol. 196: 261-281. For example, the observed CpG frequency over expected frequency can be calculated according to the formula R=(A×B)/(C×D), where R is the ratio of observed CpG frequency over expected frequency, A is the number of CpG dinucleotides in an analyzed sequence, B is the total number of nucleotides in the analyzed sequence, C is the total number of C nucleotides in the analyzed sequence, and D is the total number of G nucleotides in the analyzed sequence. Methylation state is typically determined in CpG islands, e.g., at promoter regions. It will be appreciated though that other sequences in the human genome are prone to DNA methylation such as CpA and CpT (see Ramsahoye (2000) Proc. Natl. Acad. Sci. USA 97: 5237-5242; Salmon and Kaye (1970) Biochim. Biophys. Acta. 204: 340-351; Grafstrom (1985) Nucleic Acids Res. 13: 2827-2842; Nyce (1986) Nucleic Acids Res. 14: 4353-4367; Woodcock (1987) Biochem. Biophys. Res. Commun. 145: 888-894).


As used herein, a “methylation-specific reagent” refers to a reagent that modifies a nucleotide of the nucleic acid molecule as a function of the methylation state of the nucleic acid molecule, or a methylation-specific reagent, refers to a compound or composition or other agent that can change the nucleotide sequence of a nucleic acid molecule in a manner that reflects the methylation state of the nucleic acid molecule. Methods of treating a nucleic acid molecule with such a reagent can include contacting the nucleic acid molecule with the reagent, coupled with additional steps, if desired, to accomplish the desired change of nucleotide sequence. Such methods can be applied in a manner in which unmethylated nucleotides (e.g., each unmethylated cytosine) is modified to a different nucleotide. For example, in some embodiments, such a reagent can deaminate unmethylated cytosine nucleotides to produce deoxy uracil residues. An exemplary reagent is a bisulfite reagent.


The term “bisulfite reagent” refers to a reagent comprising bisulfite, disulfite, hydrogen sulfite, or combinations thereof, useful as disclosed herein to distinguish between methylated and unmethylated CpG dinucleotide sequences. Methods of said treatment are known in the art (e.g., PCT/EP2004/011715 and WO 2013/116375, each of which is incorporated by reference in its entirety). In some embodiments, bisulfite treatment is conducted in the presence of denaturing solvents such as but not limited to n-alkylenglycol or diethylene glycol dimethyl ether (DME), or in the presence of dioxane or dioxane derivatives. In some embodiments the denaturing solvents are used in concentrations between 1% and 35% (v/v). In some embodiments, the bisulfite reaction is carried out in the presence of scavengers such as but not limited to chromane derivatives, e.g., 6-hydroxy-2,5,7,8,-tetramethylchromane 2-carboxylic acid or trihydroxybenzone acid and derivates thereof, e.g., Gallic acid (see: PCT/EP2004/011715, which is incorporated by reference in its entirety). In certain preferred embodiments, the bisulfite reaction comprises treatment with ammonium hydrogen sulfite, e.g., as described in WO 2013/116375.


A change in the nucleic acid nucleotide sequence by a methylation-specific reagent can also result in a nucleic acid molecule in which each methylated nucleotide is modified to a different nucleotide.


The term “methylation assay” refers to any assay for determining the methylation state of one or more CpG dinucleotide sequences within a sequence of a nucleic acid.


As used herein, the “sensitivity” of a given marker (or set of markers used together) refers to the percentage of samples that report a DNA methylation value above a threshold value that distinguishes between neoplastic and non-neoplastic samples. In some embodiments, a positive is defined as a histology-confirmed neoplasia that reports a DNA methylation value above a threshold value (e.g., the range associated with disease), and a false negative is defined as a histology-confirmed neoplasia that reports a DNA methylation value below the threshold value (e.g., the range associated with no disease). The value of sensitivity, therefore, reflects the probability that a DNA methylation measurement for a given marker obtained from a known diseased sample will be in the range of disease-associated measurements. As defined here, the clinical relevance of the calculated sensitivity value represents an estimation of the probability that a given marker would detect the presence of a clinical condition when applied to a subject with that condition.


As used herein, the “specificity” of a given marker (or set of markers used together) refers to the percentage of non-neoplastic samples that report a DNA methylation value below a threshold value that distinguishes between neoplastic and non-neoplastic samples. In some embodiments, a negative is defined as a histology-confirmed non-neoplastic sample that reports a DNA methylation value below the threshold value (e.g., the range associated with no disease) and a false positive is defined as a histology-confirmed non-neoplastic sample that reports a DNA methylation value above the threshold value (e.g., the range associated with disease). The value of specificity, therefore, reflects the probability that a DNA methylation measurement for a given marker obtained from a known non-neoplastic sample will be in the range of non-disease associated measurements. As defined here, the clinical relevance of the calculated specificity value represents an estimation of the probability that a given marker would detect the absence of a clinical condition when applied to a patient without that condition.


As used herein, a “selected nucleotide” refers to one nucleotide of the four typically occurring nucleotides in a nucleic acid molecule (C, G, T, and A for DNA and C, G, U, and A for RNA), and can include methylated derivatives of the typically occurring nucleotides (e.g., when C is the selected nucleotide, both methylated and unmethylated C are included within the meaning of a selected nucleotide), whereas a methylated selected nucleotide refers specifically to a nucleotide that is typically methylated and an unmethylated selected nucleotides refers specifically to a nucleotide that typically occurs in unmethylated form.


The terms “methylation-specific restriction enzyme” or “methylation-sensitive restriction enzyme” refers to an enzyme that selectively digests a nucleic acid dependent on the methylation state of its recognition site. In the case of a restriction enzyme that specifically cuts if the recognition site is not methylated or is hemi-methylated, the cut will not take place or will take place with a significantly reduced efficiency if the recognition site is methylated. In the case of a restriction enzyme that specifically cuts if the recognition site is methylated, the cut will not take place or will take place with a significantly reduced efficiency if the recognition site is not methylated. Preferred are methylation-specific restriction enzymes, the recognition sequence of which contains a CG dinucleotide (for instance a recognition sequence such as CGCG or CCCGGG). Further preferred for some embodiments are restriction enzymes that do not cut if the cytosine in this dinucleotide is methylated at the carbon atom C5.


The term “primer” refers to an oligonucleotide, whether occurring naturally as, e.g., a nucleic acid fragment from a restriction digest, or produced synthetically, that is capable of acting as a point of initiation of synthesis when placed under conditions in which synthesis of a primer extension product that is complementary to a nucleic acid template strand is induced, (e.g., in the presence of nucleotides and an inducing agent such as a DNA polymerase, and at a suitable temperature and pH). The primer is preferably single stranded for maximum efficiency in amplification, but may alternatively be double stranded. If double stranded, the primer is first treated to separate its strands before being used to prepare extension products. Preferably, the primer is an oligodeoxyribonucleotide. The primer must be sufficiently long to prime the synthesis of extension products in the presence of the inducing agent. The exact lengths of the primers will depend on many factors, including temperature, source of primer, and the use of the method.


The term “probe” refers to an oligonucleotide (e.g., a sequence of nucleotides), whether occurring naturally as in a purified restriction digest or produced synthetically, recombinantly, or by PCR amplification, that is capable of hybridizing to another oligonucleotide of interest. A probe may be single-stranded or double-stranded. Probes are useful in the detection, identification, and isolation of particular gene sequences (e.g., a “capture probe”). It is contemplated that any probe used in the present invention may, in some embodiments, be labeled with any “reporter molecule,” so that is detectable in any detection system, including, but not limited to enzyme (e.g., ELISA, as well as enzyme-based histochemical assays), fluorescent, radioactive, and luminescent systems. It is not intended that the present invention be limited to any particular detection system or label.


The term “target,” as used herein refers to a nucleic acid sought to be sorted out from other nucleic acids, e.g., by probe binding, amplification, isolation, capture, etc. For example, when used in reference to the polymerase chain reaction, “target” refers to the region of nucleic acid bounded by the primers used for polymerase chain reaction, while when used in an assay in which target DNA is not amplified, e.g., in some embodiments of an invasive cleavage assay, a target comprises the site at which a probe and invasive oligonucleotides (e.g., INVADER oligonucleotide) bind to form an invasive cleavage structure, such that the presence of the target nucleic acid can be detected. A “segment” is defined as a region of nucleic acid within the target sequence.


The term “marker”, as used herein, refers to a substance (e.g., a nucleic acid, or a region of a nucleic acid, or a protein) that may be used to distinguish non-normal cells (e.g., cancer cells) from normal cells, e.g., based on presence, absence, or status (e.g., methylation state) of the marker substance.


The term “neoplasm” as used herein refers to any new and abnormal growth of tissue. Thus, a neoplasm can be a premalignant neoplasm or a malignant neoplasm.


The term “neoplasm-specific marker,” as used herein, refers to any biological material or element that can be used to indicate the presence of a neoplasm. Examples of biological materials include, without limitation, nucleic acids, polypeptides, carbohydrates, fatty acids, cellular components (e.g., cell membranes and mitochondria), and whole cells. In some instances, markers are particular nucleic acid regions (e.g., genes, intragenic regions, specific loci, etc.). Regions of nucleic acid that are markers may be referred to, e.g., as “marker genes,” “marker regions,” “marker sequences,” “marker loci,” etc.


The term “sample” is used in its broadest sense. In one sense it can refer to an animal cell or tissue. In another sense, it refers to a specimen or culture obtained from any source, as well as biological and environmental samples. Biological samples may be obtained from plants or animals (including humans) and encompass fluids, solids, tissues, and gases. Environmental samples include environmental material such as surface matter, soil, water, and industrial samples. These examples are not to be construed as limiting the sample types applicable to the present invention.


As used herein, the terms “patient” or “subject” refer to organisms to be subject to various tests provided by the technology. The term “subject” includes animals, preferably mammals, including humans. In a preferred embodiment, the subject is a primate. In an even more preferred embodiment, the subject is a human. Further with respect to diagnostic methods, a preferred subject is a vertebrate subject. A preferred vertebrate is warm-blooded; a preferred warm-blooded vertebrate is a mammal. A preferred mammal is most preferably a human. As used herein, the term “subject” includes both human and animal subjects. Thus, veterinary therapeutic uses are provided herein. As such, the present technology provides for the diagnosis of mammals such as humans, as well as those mammals of importance due to being endangered, such as Siberian tigers; of economic importance, such as animals raised on farms for consumption by humans; and/or animals of social importance to humans, such as animals kept as pets or in zoos. Examples of such animals include but are not limited to: carnivores such as cats and dogs; swine, including pigs, hogs, and wild boars; ruminants and/or ungulates such as cattle, oxen, sheep, giraffes, deer, goats, bison, and camels; pinnipeds; and horses. Thus, also provided is the diagnosis and treatment of livestock, including, but not limited to, domesticated swine, ruminants, ungulates, horses (including racehorses), and the like. The presently-disclosed subject matter further includes a system for diagnosing a colon cancer in a subject. The system can be provided, for example, as a commercial kit that can be used to screen for a risk of colon cancer or diagnose a colon cancer in a subject from whom a biological sample has been collected. An exemplary system provided in accordance with the present technology includes assessing the methylation state of a marker described herein.


The term “amplifying” or “amplification” in the context of nucleic acids refers to the production of multiple copies of a polynucleotide, or a portion of the polynucleotide, typically starting from a small amount of the polynucleotide (e.g., a single polynucleotide molecule), where the amplification products or amplicons are generally detectable. Amplification of polynucleotides encompasses a variety of chemical and enzymatic processes. The generation of multiple DNA copies from one or a few copies of a target or template DNA molecule during a polymerase chain reaction (PCR) or a ligase chain reaction (LCR; see, e.g., U.S. Pat.t No. 5,494,810; herein incorporated by reference in its entirety) are forms of amplification. Additional types of amplification include, but are not limited to, allele-specific PCR (see, e.g., U.S. Pat. No. 5,639,611; herein incorporated by reference in its entirety), assembly PCR (see, e.g., U.S. Pat. No. 5,965,408; herein incorporated by reference in its entirety), helicase-dependent amplification (see, e.g., U.S. Pat. No. 7,662,594; herein incorporated by reference in its entirety), hot-start PCR (see, e.g., U.S. Pat. Nos. 5,773,258 and 5,338,671; each herein incorporated by reference in their entireties), intersequence-specific PCR, inverse PCR (see, e.g., Triglia, et al. (1988) Nucleic Acids Res., 16:8186; herein incorporated by reference in its entirety), ligation-mediated PCR (see, e.g., Guilfoyle, R. et al., Nucleic Acids Research, 25:1854-1858 (1997); U.S. Pat. No. 5,508,169; each of which are herein incorporated by reference in their entireties), methylation-specific PCR (see, e.g., Herman, et al., (1996) PNAS 93(13) 9821-9826; herein incorporated by reference in its entirety), miniprimer PCR, multiplex ligation-dependent probe amplification (see, e.g., Schouten, et al., (2002) Nucleic Acids Research 30(12): e57; herein incorporated by reference in its entirety), multiplex PCR (see, e.g., Chamberlain, et al., (1988) Nucleic Acids Research 16(23) 11141-11156; Ballabio, et al., (1990) Human Genetics 84(6) 571-573; Hayden, et al., (2008) BMC Genetics 9:80; each of which are herein incorporated by reference in their entireties), nested PCR, overlap-extension PCR (see, e.g., Higuchi, et al., (1988) Nucleic Acids Research 16(15) 7351-7367; herein incorporated by reference in its entirety), real time PCR (see, e.g., Higuchi, et al., (1992) Biotechnology 10:413-417; Higuchi, et al., (1993) Biotechnology 11:1026-1030; each of which are herein incorporated by reference in their entireties), reverse transcription PCR (see, e.g., Bustin, S. A. (2000) J. Molecular Endocrinology 25:169-193; herein incorporated by reference in its entirety), solid phase PCR, thermal asymmetric interlaced PCR, and Touchdown PCR (see, e.g., Don, et al., Nucleic Acids Research (1991) 19(14) 4008; Roux, K. (1994) Biotechniques 16(5) 812-814; Hecker, et al., (1996) Biotechniques 20(3) 478-485; each of which are herein incorporated by reference in their entireties). Polynucleotide amplification also can be accomplished using digital PCR (see, e.g., Kalinina, et al., Nucleic Acids Research. 25; 1999-2004, (1997); Vogelstein and Kinzler, Proc Natl Acad Sci USA. 96; 9236-41, (1999); International Patent Publication No. WO05023091A2; US Patent Application Publication No. 20070202525; each of which are incorporated herein by reference in their entireties). 5′


The term “polymerase chain reaction” (“PCR”) refers to the method of K. B. Mullis U.S. Pat. Nos. 4,683,195, 4,683,202, and 4,965,188, that describe a method for increasing the concentration of a segment of a target sequence in a mixture of genomic or other DNA or RNA, without cloning or purification. This process for amplifying the target sequence consists of introducing a large excess of two oligonucleotide primers to the DNA mixture containing the desired target sequence, followed by a precise sequence of thermal cycling in the presence of a DNA polymerase. The two primers are complementary to their respective strands of the double stranded target sequence. To effect amplification, the mixture is denatured and the primers then annealed to their complementary sequences within the target molecule. Following annealing, the primers are extended with a polymerase so as to form a new pair of complementary strands. The steps of denaturation, primer annealing, and polymerase extension can be repeated many times (i.e., denaturation, annealing and extension constitute one “cycle”; there can be numerous “cycles”) to obtain a high concentration of an amplified segment of the desired target sequence.


The length of the amplified segment of the desired target sequence is determined by the relative positions of the primers with respect to each other, and therefore, this length is a controllable parameter. By virtue of the repeating aspect of the process, the method is referred to as the “polymerase chain reaction” (“PCR”). Because the desired amplified segments of the target sequence become the predominant sequences (in terms of concentration) in the mixture, they are said to be “PCR amplified” and are “PCR products” or “amplicons.” Those of skill in the art will understand the term “PCR” encompasses many variants of the originally described method using, e.g., real time PCR, nested PCR, reverse transcription PCR (RT-PCR), single primer and arbitrarily primed PCR, etc.


As used herein, the term “nucleic acid detection assay” refers to any method of determining the nucleotide composition of a nucleic acid of interest. Nucleic acid detection assays include but are not limited to, DNA sequencing methods, probe hybridization methods, structure specific cleavage assays (e.g., the INVADER assay, (Hologic, Inc.) and are described, e.g., in U.S. Pat. Nos. 5,846,717, 5,985,557, 5,994,069, 6,001,567, 6,090,543, and 6,872,816; Lyamichev et al., Nat. Biotech., 17:292 (1999), Hall et al., PNAS, USA, 97:8272 (2000), and US 2009/0253142, each of which is herein incorporated by reference in its entirety for all purposes); enzyme mismatch cleavage methods (e.g., U.S. Pat. Nos. 6,110,684, 5,958,692, 5,851,770, herein incorporated by reference in their entireties); polymerase chain reaction (PCR), described above; branched hybridization methods (e.g., Chiron, U.S. Pat. Nos. 5,849,481, 5,710,264, 5,124,246, and 5,624,802, herein incorporated by reference in their entireties); rolling circle replication (e.g., U.S. Pat. Nos. 6,210,884, 6,183,960 and 6,235,502, herein incorporated by reference in their entireties); NASBA (e.g., U.S. Pat. No. 5,409,818, herein incorporated by reference in its entirety); molecular beacon technology (e.g., U.S. Pat. No. 6,150,097, herein incorporated by reference in its entirety); E-sensor technology (Motorola, U.S. Pat. Nos. 6,248,229, 6,221,583, 6,013,170, and 6,063,573, herein incorporated by reference in their entireties); cycling probe technology (e.g., U.S. Pat. Nos. 5,403,711, 5,011,769, and 5,660,988, herein incorporated by reference in their entireties); Dade Behring signal amplification methods (e.g., U.S. Pat. Nos. 6,121,001, 6,110,677, 5,914,230, 5,882,867, and 5,792,614, herein incorporated by reference in their entireties); ligase chain reaction (e.g., Barany Proc. Natl. Acad. Sci USA 88, 189-93 (1991)); and sandwich hybridization methods (e.g., U.S. Pat. No. 5,288,609, herein incorporated by reference in its entirety). Additional methods are described in U.S. patent application Ser. No. 15/881,409 of Allawi, et al., filed Jan. 26, 2018, incorporated herein by reference in its entirety.


In some embodiments, target nucleic acid is amplified (e.g., by polymerase chain reaction, e.g., as described by K. B. Mullis in U.S. Pat. Nos. 4,683,195, 4,683,202, and 4,965,188) and amplified nucleic acid is detected simultaneously using an invasive cleavage assay. Assays configured for performing a detection assay (e.g., invasive cleavage assay) in combination with an amplification assay are described in U.S. Pat. No. 9,096,893, incorporated herein by reference in its entirety for all purposes. Additional amplification plus invasive cleavage detection configurations, termed the QuARTS method, are described in, e.g., in U.S. Pat. Nos. 8,361,720; 8,715,937; 8,916,344; and 9,212,392, each of which is incorporated herein by reference for all purposes.


The term “invasive cleavage structure” as used herein refers to a cleavage structure comprising i) a target nucleic acid, ii) an upstream nucleic acid (e.g., an invasive or “INVADER” oligonucleotide), and iii) a downstream nucleic acid (e.g., a probe), where the upstream and downstream nucleic acids anneal to contiguous regions of the target nucleic acid, and where an overlap forms between the a 3′ portion of the upstream nucleic acid and duplex formed between the downstream nucleic acid and the target nucleic acid. An overlap occurs where one or more bases from the upstream and downstream nucleic acids occupy the same position with respect to a target nucleic acid base, whether or not the overlapping base(s) of the upstream nucleic acid are complementary with the target nucleic acid, and whether or not those bases are natural bases or non-natural bases. In some embodiments, the 3′ portion of the upstream nucleic acid that overlaps with the downstream duplex is a non-base chemical moiety such as an aromatic ring structure, e.g., as disclosed, for example, in U.S. Pat. No. 6,090,543, incorporated herein by reference in its entirety. In some embodiments, one or more of the nucleic acids may be attached to each other, e.g., through a covalent linkage such as nucleic acid stem-loop, or through a non-nucleic acid chemical linkage (e.g., a multi-carbon chain).


A “flap oligonucleotide” or “probe oligonucleotide” refers to an oligonucleotide cleavable in a detection assay, such as an invasive cleavage assay, by a flap endonuclease. In preferred embodiments, a flap oligonucleotide forms an invasive cleavage structure with other nucleic acids, e.g., a target or template nucleic acid and an invasive oligonucleotide. Flap assay reagents may optionally contain a target or template nucleic acid to which an invasive oligonucleotide and flap oligonucleotide bind. In particularly preferred embodiments, flap assay reagents comprise a Mg++ flap assay buffer, as discussed herein.


The term “invasive oligonucleotide” refers to an oligonucleotide that hybridizes to a target nucleic acid at a location adjacent to the region of hybridization between a probe and the target nucleic acid, wherein the 3′ end of the invasive oligonucleotide comprises a portion (e.g., a chemical moiety, or one or more nucleotides) that overlaps with the region of hybridization between the probe and target. The 3′ terminal nucleotide of the invasive oligonucleotide may or may not base pair a nucleotide in the target. In some embodiments, the invasive oligonucleotide contains sequences at its 3′ end that are substantially the same as sequences located at the 5′ end of a portion of the probe oligonucleotide that anneals to the target strand.


As used herein, the phrase “not substantially complementary” as used in reference to a probe flap or arm means that the flap portion is sufficiently non-complementary not to hybridize selectively to a nucleic acid sequence, e.g., a target nucleic acid or amplified DNA, under the designated annealing conditions or stringent conditions, encompassing the terms “substantially non-complementary” and “perfectly non-complementary.”


The term “complementary” is used herein to mean that primers or probes are sufficiently complementary to hybridize selectively, e.g., to a target nucleic acid sequence under the designated annealing conditions or stringent conditions, encompassing the terms “substantially complementary” and “perfectly complementary.”


As used herein, the term “flap endonuclease” refers to a structure-specific nucleolytic enzyme that cleaves a nucleic acid flap structure, e.g., an invasive cleavage structure. Flap endonuclease include, e.g., 5′ -exonuclease domains of the DNA polymerase I proteins of Eubacteria and the FEN-1 proteins of Eukarya and Archaea. (Kaiser, et al., supra). Flap endonucleases may cleave additional structures, e.g., pseudo-Y, 5′ overhang, and gap structures. See, e.g., Shen, B., BioEssays 27:717-729 (2005); Finger, L D., Subcell Biochem. 62:301-326 (2012), and U.S. Patent Appl. Ser. No. 62/901,085, filed Sep. 16, 2019, each of which is incorporated herein in its entirety. As used herein the term “flap endonuclease substrate” refers to a nucleic acid flap structure, e.g., an invasive cleavage structure, that is recognized and cleaved by a flap endonuclease, such as a FEN-1 endonuclease.


The term “FEN-1” as used herein in reference to an enzyme refers to a non-polymerase flap endonuclease from a eukaryote or archaeal organism, as encoded by a FEN-1 gene. See, e.g., Kaiser, et al., supra, WO 02/070755, and U.S. Pat. No. 7,122,364, which are incorporated by reference herein in their entireties for all purposes. The term “FEN-1 activity” refers to any enzymatic activity of a FEN-1 enzyme. FEN-1 endonucleases also comprise modified FEN-1 proteins, e.g., chimerical proteins comprising portions of FEN-1 enzymes from different organisms, and enzymes comprising one or more mutations (e.g., substitutions, deletions, insertions, etc.), as described in WO 02/070755, and U.S. Pat. No. 7,122,364.


As used herein, the terms “flap endonuclease assay” “flap assay” refer to a detection assay in which formation and cleavage of a flap endonuclease substrate is used to evaluate a sample for the presence of or an amount of a target analyte, e.g., a target nucleic acid. As used herein, the term “flap endonuclease assay” includes “INVADER” invasive cleavage assays and QuARTS assays, as described above.


As used herein, the term “flap assay reagents” or “invasive cleavage assay reagents” refers to a collection of all reagents required for performing a flap assay or invasive cleavage assay. As is known in the art, flap assays generally include oligonucleotides for forming an invasive cleavage structure, a flap endonuclease and, optionally, a FRET cassette or 5′ hairpin FRET reporter. Flap assay reagents may optionally contain a target to which the invasive oligonucleotide and flap oligonucleotide bind.


As used herein, the term “cleaved flap” refers to a single-stranded oligonucleotide that is a cleavage product of a flap assay.


The term “cassette,” when used in reference to a flap cleavage reaction, refers to an oligonucleotide or combination of oligonucleotides configured to generate a detectable signal in response to cleavage of a flap or probe oligonucleotide, e.g., in a primary or first cleavage structure formed in a flap cleavage assay. In preferred embodiments, the cassette hybridizes to a non-target cleavage product produced by cleavage of a flap oligonucleotide to form a second overlapping cleavage structure, such that the cassette can then be cleaved by the same enzyme, e.g., a FEN-1 endonuclease.


In some embodiments, the cassette is a single oligonucleotide comprising a hairpin portion (i.e., a region wherein one portion of the cassette oligonucleotide hybridizes to a second portion of the same oligonucleotide under reaction conditions, to form a duplex). In other embodiments, a cassette comprises at least two oligonucleotides comprising complementary portions that can form a duplex under reaction conditions. In preferred embodiments, the cassette comprises a label, e.g., a fluorophore. In particularly preferred embodiments, a cassette comprises labeled moieties that produce a FRET effect. In such embodiments, the cassette may be referred to as a “FRET cassette.” See, for example, See also U.S. Patent Appl. Ser. No. 62/249,097, filed Oct. 30, 2015, Ser. No. 15/335,096, filed Oct. 26, 2016; and International Appl. Ser. No. PCT/US16/58875, filed Oct. 26, 2016, each of which is incorporated herein by reference in its entirety, for all purposes.


This block is slightly revised compared to 35006 but is essentially the same As used herein, the term “FRET cassette” refers to a hairpin oligonucleotide that contains a fluorophore moiety and a nearby quencher moiety that quenches the fluorophore. Hybridization of a cleaved flap (e.g., from cleavage of a target-specific probe in a PCR-flap assay assay) with a FRET cassette produces a secondary substrate for the flap endonuclease, e.g., a FEN-1 enzyme. Once this substrate is formed, the 5′ fluorophore-containing base can be cleaved from the cassette by the flap endonuclease, thereby generating a fluorescence signal. In preferred embodiments, a FRET cassette comprises an unpaired 3′ portion to which a cleavage product, e.g., a portion of a cleaved flap oligonucleotide, can hybridize to from an invasive cleavage structure cleavable by a FEN-1 endonuclease.


As used herein, the term “PCR-flap assay” is used interchangeably with the term “PCR-invasive cleavage assay” and refers to an assay configuration combining PCR target amplification and detection of the amplified DNA by formation of a first overlap cleavage structure comprising amplified target DNA, and a second overlap cleavage structure comprising a cleaved 5′ flap from the first overlap cleavage structure and a labeled reporter oligonucleotide, e.g., a “FRET cassette” or 5′ hairpin FRET reporter oligonucleotide. In the PCR-flap assay as used herein, the assay reagents comprise a mixture containing DNA polymerase, FEN-1 endonuclease, a primary probe comprising a portion complementary to a target nucleic acid, and a FRET cassette or 5′ hairpin FRET reporter, and the target nucleic acid is amplified by PCR and the amplified nucleic acid is detected simultaneously (i.e., detection occurs during the course of target amplification). PCR-flap assays include the QuARTS assays described in U.S. Pat. Nos. 8,361,720; 8,715,937; and 8,916,344, and the amplification assays of US Pat. No. 9,096,893 (for example, as diagrammed in FIG. 1 of that patent), each of which is incorporated herein by reference in its entirety.


As used herein, the term “PCR-flap assay reagents” refers to one or more reagents for detecting a target nucleic acid in a PCR-flap assay, the reagents comprising nucleic acid molecules capable of participating in amplification of a target nucleic acid and in formation of a flap endonuclease substrate in the presence of the target nucleic acid, preferably in a mixture containing DNA polymerase, FEN-1 endonuclease and a FRET cassette or 5′ hairpin FRET reporter.


As used herein, the term “FRET” refers to fluorescence resonance energy transfer, a process in which moieties (e.g., fluorophores) transfer energy e.g., among themselves, or, from a fluorophore to a non-fluorophore (e.g., a quencher molecule). In some circumstances, FRET involves an excited donor fluorophore transferring energy to a lower-energy acceptor fluorophore via a short-range (e.g., about 10 nm or less) dipole-dipole interaction. In other circumstances, FRET involves a loss of fluorescence energy from a donor and an increase in fluorescence in an acceptor fluorophore. In still other forms of FRET, energy can be exchanged from an excited donor fluorophore to a non-fluorescing molecule (e.g., a quenching molecule). FRET is known to those of skill in the art and has been described (See, e.g., Stryer et al., 1978, Ann. Rev. Biochem., 47:819; Selvin, 1995, Methods Enzymol., 246:300; Orpana, 2004 Biomol Eng 21, 45-50; Olivier, 2005 Mutant Res 573, 103-110, each of which is incorporated herein by reference in its entirety).


In an exemplary flap detection assay, an invasive oligonucleotide and flap oligonucleotide are hybridized to a target nucleic acid to produce a first complex having an overlap as described above. An unpaired “flap” is included on the 5′ end of the flap oligonucleotide. The first complex is a substrate for a flap endonuclease, e.g., a FEN-1 endonuclease, which cleaves the flap oligonucleotide to release the 5′ flap portion. In a secondary reaction, the released 5′ flap product serves as an invasive oligonucleotide on a FRET cassette to again create the structure recognized by the flap endonuclease, such that the FRET cassette is cleaved. When the fluorophore and the quencher are separated by cleavage of the FRET cassette, a detectable fluorescent signal above background fluorescence is produced.


The term “real time” as used herein in reference to detection of nucleic acid amplification or signal amplification refers to the detection or measurement of the accumulation of products or signal in the reaction while the reaction is in progress, e.g., during incubation or thermal cycling. Such detection or measurement may occur continuously, or it may occur at a plurality of discrete points during the progress of the amplification reaction, or it may be a combination. For example, in a polymerase chain reaction, detection (e.g., of fluorescence) may occur continuously during all or part of thermal cycling, or it may occur transiently, at one or more points during one or more cycles. In some embodiments, real time detection of PCR or QuARTS reactions is accomplished by determining a level of fluorescence at the same point (e.g., a time point in the cycle, or temperature step in the cycle) in each of a plurality of cycles, or in every cycle. Real time detection of amplification may also be referred to as detection “during” the amplification reaction.


As used herein, the term “quantitative amplification data set” refers to the data obtained during quantitative amplification of the target sample, e.g., target DNA. In the case of quantitative PCR or QuARTS assays, the quantitative amplification data set is a collection of fluorescence values obtained at during amplification, e.g., during a plurality of, or all of the thermal cycles. Data for quantitative amplification is not limited to data collected at any particular point in a reaction, and fluorescence may be measured at a discrete point in each cycle or continuously throughout each cycle.


The abbreviations “Ct” and “Cp” as used herein in reference to data collected during real time PCR and PCR+INVADER assays refer to the cycle at which signal (e.g., fluorescent signal) crosses a predetermined threshold value indicative of positive signal. Various methods have been used to calculate the threshold that is used as a determinant of signal verses concentration, and the value is generally expressed as either the “crossing threshold” (Ct) or the “crossing point” (Cp). Either Cp values or Ct values may be used in embodiments of the methods presented herein for analysis of real-time signal for the determination of the percentage of variant and/or non-variant constituents in an assay or sample.


As used herein, the term “control” when used in reference to nucleic acid detection or analysis refers to a nucleic acid having known features (e.g., known sequence, known copy-number per cell), for use in comparison to an experimental target (e.g., a nucleic acid of unknown concentration). A control may be an endogenous, preferably invariant gene against which a test or target nucleic acid in an assay can be normalized. Such normalizing controls for sample-to-sample variations that may occur in, for example, sample processing, assay efficiency, etc., and allows accurate sample-to-sample data comparison. Genes that find use for normalizing nucleic acid detection assays on human samples include, e.g., (3-actin, ZDHHCJ, and B3GALT6 (see, e.g., U.S. patent application Ser. No. 14/966,617 and 62/364,082, each incorporated herein by reference.


Controls may also be external. For example, in quantitative assays such as qPCR, QuARTS, etc., a “calibrator” or “calibration control” is a nucleic acid of known sequence, e.g., having the same sequence as a portion of an experimental target nucleic acid, and a known concentration or series of concentrations (e.g., a serially diluted control target for generation of calibration curved in quantitative PCR). Typically, calibration controls are analyzed using the same reagents and reaction conditions as are used on an experimental DNA. In certain embodiments, the measurement of the calibrators is done at the same time, e.g., in the same thermal cycler, as the experimental assay. In preferred embodiments, multiple calibrators may be included in a single plasmid, such that the different calibrator sequences are easily provided in equimolar amounts. In particularly preferred embodiments, plasmid calibrators are digested, e.g., with one or more restriction enzymes, to release calibrator portion from the plasmid vector. See, e.g., WO 2015/066695, which is included herein by reference. In some embodiments, calibrator DNAs are synthetic, e.g. as described in U.S. patent application Ser. No. 15/105,178, incorporated herein by reference.


As used herein “ZDHHC1” refers to a gene encoding a protein characterized as a zinc finger, DHHC-type containing 1, located in human DNA on Chr 16 (16q22.1) and belonging to the DHHC palmitoyltransferase family.


As used herein, the term “process control” refers to an exogenous molecule, e.g., an exogenous nucleic acid added to a sample prior to extraction of target DNA that can be measured post-extraction to assess the efficiency of the process and be able to determine success or failure modes. The nature of the process control nucleic acid used is usually dependent on the assay type and the material that is being measured. For example, if the assay being used is for detection and/or quantification of double stranded DNA or mutations in it, then double stranded DNA process controls are typically spiked into the samples pre-extraction. Similarly, for assays that monitor mRNA or microRNAs, the process controls used are typically either RNA transcripts or synthetic RNA. See, e.g., U.S. Pat. Appl. Ser. No. 62/364,049, filed Jul. 19, 2016, which is incorporated herein by reference, and which describes use of zebrafish DNA as a process control for human samples.


As used herein, the term “zebrafish DNA” is distinct from bulk “fish DNA”) e.g., purified salmon DNA) and refers to DNA isolated from Danio rerio, or created in vitro (e.g., enzymatically, synthetically) to have a sequence of nucleotides found in DNA from Danio rerio.


In preferred embodiments, the zebrafish DNA is a methylated DNA added as a detectable control DNA, e.g., a process control for verifying DNA recovery through sample processing steps. In particular, zebrafish DNA comprising at least a portion of the RASSF 1 gene finds use as a process control, e.g., for human samples, as described in U.S. Pat. Appl. Ser. No. 62/364,049.


As used herein the term “fish DNA” is distinct from zebrafish DNA and refers to bulk (e.g., genomic) DNA isolated from fish, e.g., as described in U.S. Pat. No.9,212,392. Bulk purified fish DNA is commercially available, e.g., provided in the form of cod and/or herring sperm DNA (Roche Applied Science, Mannheim, Germany) or salmon DNA (USB/Affymetrix).


As used herein, the terms “particle” and “beads” are used interchangeably, and the terms “magnetic particles” and “magnetic beads” are used interchangeably and refer to particles or beads that respond to a magnetic field. Typically, magnetic particles comprise materials that have no magnetic field but that form a magnetic dipole when exposed to a magnetic field, e.g., materials capable of being magnetized in the presence of a magnetic field but that are not themselves magnetic in the absence of such a field. The term “magnetic” as used in this context includes materials that are paramagnetic or superparamagnetic materials. The term “magnetic”, as used herein, also encompasses temporarily magnetic materials, such as ferromagnetic or ferrimagnetic materials with low Curie temperatures, provided that such temporarily magnetic materials are paramagnetic in the temperature range at which silica magnetic particles containing such materials are used according to the present methods to isolate biological materials.


As used herein, the term “kit” refers to any delivery system for delivering materials. In the context of cell sampling devices, such delivery systems include systems that allow for the storage, transport, delivery, or use of devices and/or for processing samples obtained with devices (e.g., drinkable solutions, lubricants, or anesthetics for use of a swallowable device, sample stabilizing reagents; sample processing reagents such as particles, buffers, denaturants, oligonucleotides, filters, assay reaction components, etc. in the appropriate containers) and/or supporting materials (e.g., sample processing or sample storage vessels, written instructions for performing a procedure, etc.) from one location to another. For example, kits include one or more enclosures (e.g., boxes) containing the relevant sampling device and reagents and/or supporting materials. As used herein, the term “fragmented kit” refers to a delivery system comprising two or more separate containers that each contains a subportion of the total kit components. The containers may be delivered to the intended recipient together or separately. For example, a first container may contain materials for sample collection and a buffer, while a second container contains capture oligonucleotides and denaturant. The term “fragmented kit” is intended to encompass kits containing Analyte specific reagents (ASR's) regulated under section 520(e) of the Federal Food, Drug, and Cosmetic Act, but are not limited thereto. Indeed, any delivery system comprising two or more separate containers that each contains a subportion of the total kit components are included in the term “fragmented kit.” In contrast, a “combined kit” refers to a delivery system containing all of the components for sample collection, processing, and assaying in a single container (e.g., in a single box housing each of the desired components). The term “kit” includes both fragmented and combined kits.


The term “system” as used herein refers to a collection of articles for use for a particular purpose, e.g., a collection of devices, reagents, and instruments for collecting a sample (e.g., in preparation for analyzing the sample), or for collecting, processing and/or analyzing a sample for a particular purpose. In some embodiments, the articles of a system comprise instructions for use, as information supplied on e.g., an article, on paper, on recordable media (e.g., DVD, flash drive, etc.). In some embodiments, instructions direct a user to an online location, e.g., a website for viewing, hearing, and/or downloading instructions. In some embodiments, instructions or other information are provided as an application (“app”) for a mobile device.


As used herein, the term “information” refers to any collection of facts or data. In reference to information stored or processed using a computer system(s), including but not limited to internets, the term refers to any data stored in any format (e.g., analog, digital, optical, etc.). As used herein, the term “information related to a subject” refers to facts or data pertaining to a subject (e.g., a human, plant, or animal). The term “genomic information” refers to information pertaining to a genome including, but not limited to, nucleic acid sequences, genes, percentage methylation, allele frequencies, RNA expression levels, protein expression, phenotypes correlating to genotypes, etc. “Allele frequency information” refers to facts or data pertaining to allele frequencies, including, but not limited to, allele identities, statistical correlations between the presence of an allele and a characteristic of a subject (e.g., a human subject), the presence or absence of an allele in an individual or population, the percentage likelihood of an allele being present in an individual having one or more particular characteristics, etc.





DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present technology will become better understood with regard to the following drawings:



FIGS. 1A-1D show various embodiments of the dissolvable capsule described herein. FIG. 1A shows a capsule having a first closed end and a second closed end. FIG. 1B shows a capsule having a first closed end and a second open end. FIG. 1C shows a capsule having a first closed end and a second closed end and multiple openings. FIG. 1D shows a capsule having a first closed end and a second open end and multiple openings.



FIG. 2 shows an embodiment of the ingestible cell sampling device described herein. The device comprises an abrasive sponge housed in a compressed state within a dissolvable capsule having a first closed end and a second closed end, a spherical molded cap having an interior surface in contact with the exterior surface of the second closed end, and a suture attached to the molded cap.



FIG. 3 shows an embodiment of the ingestible cell sampling device described herein. The device comprises an abrasive sponge housed in a compressed state within a dissolvable capsule having a first closed end and a second closed end, a spherical molded cap having an interior surface in contact with the exterior surface of the second closed end, and a suture attached to the molded cap. The device further includes multiple openings along the cylindrical edge of the dissolvable capsule, such that the abrasive sponge is exposed to the external environment at these openings.



FIG. 4 shows an embodiment of the ingestible cell sampling device described herein. The device comprises an abrasive sponge housed in a compressed state within a dissolvable capsule having a first closed end and a second open end, a spherical molded cap having an interior surface in contact with the abrasive sponge, and a suture attached to the molded cap. The molded cap covers the second open end of the dissolvable capsule.



FIG. 5 shows an embodiment of the ingestible cell sampling device described herein. The device comprises an abrasive sponge housed in a compressed state within a dissolvable capsule having a first closed end and a second open end, a spherical molded cap having an interior surface in contact with the abrasive sponge, and a suture attached to the molded cap. The molded cap covers the second open end of the dissolvable capsule. The device further comprises multiple openings along the cylindrical edge of the dissolvable capsule.



FIGS. 6A-6D show various embodiments of the abrasive sponge described herein. FIG. 6A shows a cylindrical shaped abrasive sponge comprising a portion of material from the center removed. Approximately 25% of the material from the center of the sponge is removed. FIG. 6B shows a similar sponge wherein a larger portion of material from the center is removed. Approximately 50% of the material from the center of the sponge is removed. FIG. 6C shows a cylindrical sponge wherein multiple portions from the edge of the sponge are removed to create a pinwheel shape from the top view. FIG. 6D shows a cylindrical sponge wherein multiple portions from the edge of the sponge are removed to create a cross shape from the top view.



FIGS. 7A-7B show various views of an abrasive sponge wherein a portion (about 25%) of material from the center of the sponge is removed. The suture material passes through the abrasive sponge and attaches to the molded cap. The uncompressed diameter of the abrasive sponge is about 30 mm (FIG. 7A). A portion of material is removed from the center of the abrasive sponge, and the abrasive sponge is attached to the interior surface of the molded cap by an adhesive (FIG. 7B).



FIGS. 8A-8B show various views of an abrasive sponge wherein a portion (about 50%) of material from the center of the sponge is removed. The suture material passes through the abrasive sponge and attaches to the molded cap. The uncompressed diameter of the abrasive sponge is about 30 mm (FIG. 8A). A portion of material is removed from the center of the abrasive sponge, and the abrasive sponge is attached to the interior surface of the molded cap by an adhesive (FIG. 8B).



FIGS. 9A-9B show various views of an abrasive sponge wherein multiple portions of material from the edge of the sponge are removed. The uncompressed diameter of the abrasive sponge is about 30 mm (FIG. 9A). Multiple portions of material from the edge of the sponge are removed, to generate a sponge having a pinwheel shape from the top view (FIG. 9B).



FIGS. 10A-10B show various views of an abrasive sponge wherein multiple portions of material from the edge of the sponge are removed. The uncompressed diameter of the abrasive sponge is about 30 mm (FIG. 10A). Multiple portions of material from the edge of the sponge are removed, to generate a sponge having a cross shape from the top view (FIG. 10B).



FIGS. 11A-11D show various embodiments of methods for attaching the string to the molded cap. FIG. 11A shows an embodiment where the suture is attached to the molded cap by means of a knot. The molded cap sits on the outside of a closed end of the capsule. FIG. 11B shows an embodiment where the molded cap covers an open end of the capsule. The string is attached to the molded cap by means of a knot, and the molded cap comprises an elongated cylindrical edge, the circumference of which fits within the circumference of the open end of the capsule. FIG. 11C shows an embodiment where the molded cap is a button. The button fits within the capsule and the string is attached to the button by means of a knot. FIG. 11D shows an embodiment where the molded cap is a button. The button fits within the capsule and the string is attached to the button by means of a knot.



FIG. 12 shows multiple views of the embodiment for attachment shown in FIG. 11A. The molded cap comprises two holes through which the string is threaded (left). The knot to secure the string to the cap is tied on the inside of the molded cap (center). The molded cap fits over a closed end of the dissolvable capsule, such that the interior surface of the molded cap is in contact with the exterior surface of the closed end of the capsule (right).



FIG. 13 shows multiple views of the embodiment for attachment shown in FIG. 11B. The molded cap comprises two holes through which the string is threaded (left). The knot to secure the string to the cap is tied on the inside of the molded cap (center). The molded cap comprises an elongated cylindrical edge, the circumference of which fits within the circumference of the open end of the capsule (center, right). The exterior surface of the molded cap is in contact with the external environment.



FIG. 14 shows multiple views of the embodiment for attachment shown in FIG. 11C. The molded cap is a button. The button comprises two holes through which the string is threaded (left). The knot to secure the string to the button is tied on the inside of the molded cap (center). The button fits within the capsule (right).



FIG. 15 shows multiple views of the embodiment for attachment shown in FIG. 11D. The molded cap is a button. The button comprises a bar feature molded into the cap (left). The string wraps around the bar feature, and the knot to secure the string to the button is tied on the inside of the molded cap (center). The button fits within the capsule (right).



FIG. 16 shows schematic diagrams of selected biomarker target regions in unconverted form and bisulfite-converted form. Exemplary flap assay primers and probes for detection of bisulfite-converted target DNA are shown.



FIG. 17 provides a table of nucleic acid sequences and corresponding SEQ ID NOS.



FIG. 18 provides a table showing data and results from the assay of Example 2.



FIG. 19 provides a table showing data and results from the assay of Example 2.



FIG. 20 provides a schematic drawing showing a combined PCR- invasive cleavage assay (“PCR-flap assay”), e.g., a QuARTS assay in which three different regions of a target nucleic acid, e.g., a methylation marker, are amplified by primer pairs specific for each of the different regions, and in the presence of different flap probes, each one specific for one of the different regions, but each having the same flap arm sequence. The flaps release during each of the PCR-flap assays all report to the same FRET cassette to produce fluorescence signal from the same fluorophore.





DETAILED DESCRIPTION OF THE INVENTION

The technology relates to cell sampling devices. In particular, the present invention relates to ingestible cell sampling devices and their use in methods for detecting various abnormalities in a subject. Provided herein is technology relating to selection and use of nucleic acid markers for use in assays for detection and quantification of DNA, e.g., methylated DNA. In particular, the technology relates to use of methylation assays to detect cancer in the digestive system, e.g., in the esophagus or the colon.


In this detailed description of the various embodiments, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the embodiments disclosed. One skilled in the art will appreciate, however, that these various embodiments may be practiced with or without these specific details. In other instances, structures and devices are shown in block diagram form. Furthermore, one skilled in the art can readily appreciate that the specific sequences in which methods are presented and performed are illustrative and it is contemplated that the sequences can be varied and still remain within the spirit and scope of the various embodiments disclosed herein.


The ingestible cell sampling devices described herein are advantageous in that the devices provide improved safety for use in a subject. For example, the ingestible cell sampling devices described herein are designed to prevent detachment of the string from the molded cap, thus preventing loss of the device within a subject. As another example, the ingestible cell sampling devices described herein are designed to minimize the risk of the sponge detaching from the string during retrieval of the device, thus also preventing loss of the device within the subject. Furthermore, the devices described herein use materials that prevent laceration to the esophagus upon withdrawal of the device. The devices are easily swallowed by the subject, with a rapid dissolution of the capsule and expansion of the sponge, thus minimizing the total time required to collect an esophageal sample from the subject. Furthermore, the sponge comprises multiple features that enable for maximal surface area to capture sufficient tissue from a subject. Accordingly, described herein are ingestible cell sampling devices with maximal sampling capabilities having enhanced safety and tolerability for use in a subject.


In some embodiments, provided herein are ingestible cell sampling devices. The devices comprise an abrasive sponge housed within a dissolvable capsule, a molded cap, and a string attached to the molded cap.


The abrasive sponge may comprise any suitable material. Preferably, the material is capable of being compressed and retained in a compressed state by the dissolvable capsule. For example, the abrasive sponge may comprise a reticulated material. In some embodiments, the reticulated material comprises 10-35 pores per inch of material. For example, the reticulated material may comprise about 10, about 15, about 20, about 25, about 30, or about 35 pores per inch of material. The material may be any suitable porous, low-density material capable of collecting esophageal cells from a subject. For example, the abrasive sponge may comprise reticulated polyurethane.


The porosity of the abrasive sponge may be at least 80%. For example, the porosity may be at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%.


The abrasive sponge may be of any suitable size and shape. The size and shape of the sponge may depend on the size of the capsule. In some embodiments, the abrasive sponge is of a suitable size and shape to allow for compression into a capsule suitable for oral administration (e.g. ingestion), and subsequent facile removal from the esophagus and throat of a subject after dissolution of the capsule and restoration of the sponge to its uncompressed size. For example, the sponge may be spherical in shape with a diameter of about 20-40 mm in an uncompressed state. For example, the sponge may be spherical in shape with a diameter of about 20 mm, about 25 mm, about 30 mm, about 35 mm, or about 40 mm in an uncompressed state. For example, the sponge may be spherical in shape with a diameter of 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, or 30 mm in an uncompressed state.


The abrasive sponge may be compressed to a suitable size and housed within the dissolvable capsule in a compressed state. For example, the compressed sponge may have a diameter of about 1 mm to about 15 mm. For example, the compressed sponge may have a diameter of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm in a compressed state.


In some embodiments, the dissolution of the dissolvable capsule releases the abrasive sponge from compression and allows the abrasive sponge to expand. In some embodiments, the abrasive sponge expands to its uncompressed size following dissolution of the dissolvable capsule. In some embodiments, the abrasive sponge expands to substantially the same size as its original, uncompressed size prior to packaging within the capsule. As a nonlimiting example, the abrasive sponge may expand to within 10% of the original, uncompressed size following dissolution of the dissolvable capsule. For example, the sponge may expand to within 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% of the original, uncompressed size following dissolution of the dissolvable capsule. For example, the original, uncompressed size may be 30 mm and the sponge may expand to 27-30mm following dissolution of the capsule.


In some embodiments, the uncompressed sponge is uniform in shape. For example, the uncompressed sponge may be uniformly spherical in shape. In some embodiments, the uncompressed sponge may be spherical in shape with a protrusion that extends a portion of the abrasive sponge material into the dissolvable capsule. This protrusion is exemplified in FIG. 8B.


In some embodiments the abrasive sponge is formed to have concavities or indentations, or other external or internal spaces devoid of sponge material (“void spaces”), as may be provided by removing at least one portion of the abrasive sponge. As used herein in reference to a shape of an abrasive sponge, a “removed” portion of a sponge refers a void space in the shaped abrasive sponge, e.g., a portion that would be removed from a simple solid form, e.g., a sphere or cylinder, to produce the final shape comprising one or more void spaces. It is understood that an abrasive sponge may be manufactured in a final form that comprises such a void space, such that no sponge material need be physically “removed” during manufacture. In some embodiments, at least one portion of material may be removed from the center of the abrasive sponge. For example, the sponge may be spherical in shape and a portion of the material may be removed from the center of the abrasive sponge. For example, such embodiments are exemplified in FIG. 6A and 6B. In some embodiments, at least one portion of material may be removed from at least one outer edge of the abrasive sponge. For example, the sponge may be spherical in shape and at least one portion of the material may be removed the edge of the abrasive sponge. Various embodiments are exemplified in FIG. 6C and 6D. For example, multiple portions of material may be removed from the edge of the sponge to generate a pinwheel shape (as shown in FIG. 6C) or a cross-shape (as shown in FIG. 6D), when the sponge is viewed from the top.


Any suitable sized portion may be removed from the sponge. For example, 5%, 10%, 15%, 20%, 25%, 30%, 35% 40%, 45%, 50%, or more of the material may be removed from the sponge. In some embodiments, removal of a portion of the material facilitates compression of the sponge into a suitable sized capsule for ingestion by a subject. In some embodiments, removal of a portion of the material from the sponge facilitates rapid expansion of the sponge following dissolution of the dissolvable capsule. In some embodiments, removal of a portion of the material from the sponge increases the surface area of the sponge available for collecting esophageal cells in the subject.


The abrasive sponge is housed within a dissolvable capsule. Accordingly, the abrasive sponge may be compressed into a cylindrical shape to fit into the dissolvable capsule. The dissolvable capsule may comprise any suitable material. For example, the dissolvable capsule may comprise gelatin, starch, or a cellulosic material as known in the art. In some embodiments, the dissolvable may be a vegan or vegetarian capsule (e.g., exclusive of all animal products, or free of products from certain types of animals; e.g. gelatin-free capsule).


The dissolvable capsule may be made of a suitable material. In some embodiments, the dissolvable capsule comprises a suitable material that dissolves within 10 minutes of entering the stomach cavity of a subject. For example, the dissolvable capsule may dissolve approximately within 10 minutes, within 9 minutes, within 8 minutes, within 7 minutes, within 6 minutes, within 5 minutes, within 4 minutes, within 3 minutes, within 2 minutes, or within 1 minute of exposure to the stomach cavity of a subject. Preferably, the dissolvable capsule dissolves within 5 minutes of exposure to the stomach cavity of the subject.


In some embodiments, the dissolvable capsule comprises a first closed end and a second closed end. For example, a dissolvable capsule comprising a first closed end and a second open end is shown in FIG. 1A. In other embodiments, the dissolvable capsule comprises a first closed end and a second open end. For example, a dissolvable capsule comprising a first closed end and a second open end is shown in FIG. 1B.


In some embodiments, the dissolvable capsule comprises one or more openings, such that a portion of the abrasive sponge is exposed to the external environment at the one or more openings. The presence of one or more openings may facilitate a faster dissolution time of the capsule upon ingestion by a subject. In some embodiments, the dissolvable capsule comprises one opening. In some embodiments, the dissolvable capsule comprises two or more openings. Representative images of capsules containing one or more openings are shown in FIG. 1C (capsule having a first closed end and a second open end) and FIG. 1D (capsule having a first closed end and a second open end).


The one or more openings may be any suitable size and shape that allow for exposure of the abrasive sponge to the external environment without substantially diminishing the ability of the capsule to retain the sponge in a compressed state. The one or more openings may be in any suitable location on the dissolvable capsule. For example, the dissolvable capsule may comprise one or more openings on a closed end of the capsule. As another example, the dissolvable capsule may comprise one or more openings on a cylindrical edge of the capsule.


The ingestible cell sampling device further comprises a molded cap. In some embodiments, the molded cap is hemispherical in shape. In some embodiments, the molded cap is cylindrical in shape (e.g., a button). In some embodiments, the molded cap is connected to the capsule. For example, the molded cap may be connected to the capsule by an adhesive. In some embodiments, the molded cap is connected to the abrasive sponge. For example, the molded cap may be connected to the abrasive sponge by an adhesive. In some embodiments, the cell sampling device may comprise a capsule comprising a first closed end and a second closed end, and a hemispherical molded cap may cover one of the closed ends of the capsule. For example, the molded cap may comprise an internal surface in contact with an external surface of one end of the capsule and an exterior surface in contact with the external environment (as exemplified in FIG. 2). In some embodiments, the molded cap comprises an interior surface in contact with the abrasive sponge and an exterior surface. In some embodiments, the exterior surface may be in contact with the external environment. For example, the capsule may comprise a first closed end and a second open end, and the molded cap may cover the second open end of the capsule. For example, the molded cap may comprise an elongated cylindrical edge, the circumference of which fits within the circumference of the capsule (as exemplified in FIG. 4).


In some embodiments, the molded cap comprises an interior surface in contact with the abrasive sponge and an exterior surface in contact with an internal surface of one end of the capsule. For example, the capsule may comprise a first closed end and a second closed end, and a hemispherical molded cap may comprise an interior surface in contact with the abrasive sponge and an exterior surface in contact with the internal surface of one closed end of the capsule (e.g., the molded cap is fitted within the capsule). In some embodiments, the capsule may comprise a first closed end and a second closed end, and a cylindrically shaped molded cap (e.g., a button) may be fitted inside the capsule. In such embodiments, the button may be fitted inside the capsule such that the rim of the molded cap is in contact with the capsule, the bottom surface of the molded cap is in contact with the abrasive sponge, and the top surface of the molded cap is not in direct contact with the interior surface of the capsule (as exemplified in FIG. 14 and FIG. 15).


In embodiments wherein the interior surface of the molded cap is in contact with the abrasive sponge, the interior surface of the molded cap may be attached to the abrasive sponge. For example, the interior surface of the molded cap may be attached to the abrasive sponge by an adhesive.


In embodiments where a surface of the molded cap is in contact with the capsule, the molded cap may be attached to the capsule (e.g. by an adhesive).


The ingestible cell sampling device further comprises a string attached to the molded cap. The string may be attached to the molded cap by any suitable means, including but not limited to crimping, over-molding, adhesive, melting, wrapping, or taping. In some embodiments, the string is attached to the molded cap by a knot. Any suitable type of knot may be used. For example, the knot may be a hitch knot. The term “hitch knot” refers to a type of knot used to tie a string to an object or to another string. The term encompasses many distinct types of hitch knots, including an alternate ring hitching, anchor bend variant, bale sling hitch, barrel hitch, becket hitch, blackwall hitch, blake's hitch, boom hitch, bottom loaded release hitch, buntline hitch, cat's paw, chain hitch, clinging clara, clove hitch, continuous ring hitching, cow hitch variant, cow hitch with toggle, cow hitch, double half hitches, Farrimond friction hitch, garda hitch, ground-line hitch, half hitch, halter hitch, highpoint hitch, highwayman's hitch, hitching tie, icicle hitch, killick hitch, knute hitch, lighterman's hitch, magnus hitch, marline hitching, marlinespike hitch, masthead knot, midshipman's hitch, munter hitch, munter friction hitch, ossel hitch, palomar knot, pile hitch, prusik knot, reverse half hitches, round hitch, round turn and two half hitches, sailor's gripping hitch, sailor's hitch, siberian hitch, single hitch, slippery hitch, snell knot, snuggle hitch, taut-line hitch, timber hitch, trilene knot, trucker's hitch, tugboat hitch, uni knot, or a wagoner's hitch knot. In some embodiments, the hitch knot is a double overhand knot.


In some embodiments, the knot may be a binding knot. The term “binding knot” refers to a type of knot used to keep an object or multiple objects together, using a string that passes at least once around them. Suitable binding knots include, for example, a boa knot, a bottle sling, a bowline knot, a constrictor knot, a corned beef knot, a granny knot, a ground-line hitch, a Miller's knot, a Packer's knot, a reef knot, a strangle knot, a surgeon's knot, a thief knot, a jamming knot, a sheet bend, or a common whipping knot. The type of knot may be selected to allow for ease of manufacturing while also providing a stable means of connecting the string to the molded cap.


The molded cap may comprise any suitable feature to enable attachment of the string to the cap. For example, the molded cap may comprise two holes through which the string can be threaded and tied into a suitable knot. The string can be threaded through the first hole, pass through the external environment, and re-enter the interior of the capsule by passing through the second hole, before a knot can be tied on the interior of the capsule. As another example, the molded cap may comprise a bar on which the string can be secured (as shown in FIG. 11D).


The string may comprise any suitable material. For example, the string may be a suture material (e.g. surgical suture material). The suture material may be made from a variety of materials, including biological materials or synthetic materials. For example, the suture material may comprise synthetic materials such as nylon, polyester, PVDF, polypropylene, or combinations thereof.


The string should be of a suitable thickness to allow for facile ingestion by the subject without causing lacerations to the throat. In some embodiments, the string has a thickness of 0.3 mm to 0.7 mm. For example, the string may have a thickness of 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, or 0.7 mm.


The string should be of a suitable length to allow for retrieval of the device after dissolution of the dissolvable capsule in the subject. Accordingly, the string should be long enough to allow for the abrasive sponge contained within the dissolvable capsule to reach the stomach cavity of the subject, while retaining enough string for the subject or a physician to be able to grip the string to initiate retrieval of the device. For example, the string may be at least 60 cm long. In some embodiments, the string may be 60cm to 80cm long. For example, the string may be 60 cm, 61 cm, 62 cm, 63 cm, 64 cm, 65 cm, 66 cm, 67 cm, 68c cm, 69 cm, 70 cm, 71 cm, 72 cm, 73 cm, 74 cm, 75 cm, 76 cm, 77 cm, 78 cm, 79 cm, or 80 cm long.


In some embodiments, the string may comprise markings on the string to judge the amount of string that has been swallowed. Such markings would assist in determining that the dissolvable capsule has traveled to the desired area (e.g. the stomach cavity of the subject). The markings may be spaced any suitable distance apart. For example, the markings may be spaced 1-80 cm apart. For example, the markings may be placed about 1 cm, about 5 cm, about 10 cm, about 15 cm, about 20 cm, about 25 cm, about 30 cm, about 35 cm, or about 40 cm apart.


The string should have a suitable tensile strength to minimize the risk of the string breaking during ingestion and/or retrieval of the device. For example, the string should have a suitable tensile strength to allow for the string to be pulled to retrieve the device from the subject after dissolution of the dissolvable capsule. In some embodiments, the string may comprise a handle or a grip to facilitate retrieval of the device and/or prevent swallowing of the entire string. For example, the string may comprise a handle or a grip on the end of the string that does not contain the capsule. The handle or grip may be of any suitable size and shape to facilitate retrieval and prevent swallowing of the string. The handle or grip may be an open shape (e.g. bar shape, T-shape, X-shape, etc.) or a closed shape (e.g. circular or semi-circular shape, rectangular shape, triangular shape, etc.), and may be formed from the same material as the string (e.g., may be a loop or knot in the string) or may comprise different material (e.g., plastic, metal, etc.).


In some embodiments, the string passes through a portion of the abrasive sponge. Accordingly, passing the string through the sponge will help secure the sponge to the molded cap, such that the sponge is not lost within the subject after dissolution of the dissolvable capsule. In some embodiments, the string passes through at least one surface of the dissolvable capsule. For example, the string may pass through the first closed end of the dissolvable capsule, through the abrasive sponge, and then attach to the molded cap. In some embodiments, the string may pass through the first closed end of the dissolvable capsule, through the abrasive sponge, through the second closed end of the dissolvable capsule, and then attach to the molded cap.


Further described herein are methods for collecting cells from a subject. The methods comprise providing an ingestible cell sampling device described herein to the subject. Suitable methods for providing an ingestible cell sampling device to a subject are described in U.S. Pat. No. 4,735,214, U.S. Pat. No. 10,327,742, and U.S. Pat. No. 10,292,687, each of which are incorporated herein by reference in their entireties. For example, the subject may swallow the ingestible cell sampling device described herein and a suitable amount of time may pass prior to retrieving the device from the subject. For example, the subject may swallow the ingestible cell sampling device and 10 minutes or less may be allowed to pass prior to retrieval. For example, 10 minutes, 9 minutes, 8 minutes, 7 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, or 1 minute may pass prior to retrieval. Retrieval may comprise having the subject, physician, or otherwise suitable person grab and pull on the string at a suitable rate to allow for comfortable retrieval of the device from the subject. Esophageal cells may be harvested from the abrasive sponge by any suitable means and subsequently analyzed to determine whether one or more abnormalities are present in the subject. In some embodiments, the esophageal cells may be harvested and placed in a suitable stabilization buffer prior to analysis. For example, a stabilization buffer may comprise any suitable agent or combination of agents that prevent unwanted damage to the cells (e.g. cell lysis) or damage/degradation of the nucleic acids (e.g. DNA or RNA) contained within the cell sample.


In some embodiments, esophageal cells are harvested from the abrasive sponge and analyzed to determine whether an esophageal disorder is present in the subject. Analysis may be performed by any suitable method, including protein-based tests, tissue/cell examinations (e.g., microscopy or other visual inspections), and/or nucleic acid detection assays. For example, analysis may be performed by protein-based techniques to analyze one or more biomarkers of interest. Protein-based techniques include, for example, immunohistochemistry, ELISA, western blot, flow cytometry, fluorescent in-situ hybridization (FISH), fluorescence analysis of cell sorting (FACS), mass spectrometry, etc. For example, protein-based techniques may be performed using one or more antibodies against at least one biomarker protein of interest. The biomarker protein(s) may be detected using an antibody capable of reacting with the protein(s), and subsequent visualization of the antibody. The antibody may be a polyclonal antibody or a monoclonal antibody. The use of secondary, tertiary or further antibodies may advantageously employed in order to amplify the signal and facilitate detection.


In some embodiments, esophageal cells are harvested from the abrasive sponge and examined to determine whether an esophageal disorder is present in the subject. For example, cells may be harvested from the sponge, plated on an appropriate medium, and examined by microscopy or other visual examination to determine whether characteristics indicative of an esophageal disorder are present in the cells. In some embodiments, cells may be harvested from the sponge, plated, and inspected using a microscope to determine whether one or more cancer cells are present. In some embodiments, diagnosis of an esophageal disorder may be made by visualization of a specific cell type, such as a columnar cell, which may be indicative of gastroesophageal reflux disease or complications thereof, including Barrett's Esophagus or esophageal adenocarcinoma.


In some embodiments, esophageal cells are harvested from the abrasive sponge and one or more nucleic acid detection assays are performed to determine whether an esophageal disorder is present in the subject. For example, esophageal cells may be harvested from the abrasive sponge following use in a subject, and the cells may be analyzed by one or more nucleic acid detection assays to detect levels of one or more biomarkers of an esophageal disorder. Suitable methods (e.g. nucleic acid detection assays) and biomarkers for detecting esophageal disorders are described in U.S. patent application Ser. No. 15/881,409 of Allawi, et al., filed Jan. 26, 2018, (including, e.g., ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671), and U.S. Pat. No. 10,435,755, (including, e.g., BMP3, NDRG4, VAV3, SFMBT2, D103, HUNK, ELMO1, CD1D, CDKN2A; and OPLAH), both of which are incorporated herein by reference in their entireties.


Biomarkers selected from this group may comprise 1 biomarker, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, or 33 biomarkers, alone or in any combination or subcombination, without limitation. For example, in certain embodiments, the biomarker or group of biomarkers is selected from the group consisting of ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671, while in some embodiments, the biomarker or group of biomarkers is selected from the group consisting of BMP3, NDRG4, VAV3, SFMBT2, D103, HUNK, ELMO1, CD1D, CDKN2A, and OPLAH.


In some embodiments, analysis of target DNAs comprises analysis of multiple different DNAs in a single reaction. Typical instrumentation for real-time detection of amplification reactions allows for simultaneous detection and quantification of only 3-5 fluorescent dyes. This is mainly because spectral overlap between fluorophores makes it difficult to distinguish one dye from another when the many dyes with overlap excitation and/or emission spectra are used together. When detection of a specific disease from a biological specimen requires a panel comprising more than about 5 different markers, this presents a challenge, especially when the size of the sample is limited and the markers are present in low levels, a situation often requiring use of the entirety of a sample in a single amplification run.


In some embodiments, methods described herein allow for detection of multiple different markers in the same sample by having each sample produce a result from the same dye. In the embodiment described in detail herein, multiplexed flap cleavage assays (e.g., QuARTS flap endonuclease assays) for multiple different markers produce initial cleavage products that use the same FRET cassette to produce fluorescent signal.


In preferred embodiments, the combined assay comprises several different probe oligonucleotides that each have a portion that hybridizes to a different target nucleic acid, but that all have essentially the same 5′ arm sequence. Cleavage of the probes in the presence of their respective target nucleic acids all release the same 5′ arm, and all of the released arms then combine with FRET cassettes having the same flap-binding sequence and the same dye to produce fluorescence signal by endonuclease cleavage of the FRET cassette. In other embodiments, the probes for different targets may have different flap arms that report to different FRET cassettes, wherein the different FRET cassettes all use the same reporter fluorophore.


Combining assays in this manner has multiple advantages. For example, a sample can provide a result if any one of the target sequences associated with a condition (e.g., a disease state, such as colorectal cancer) is detected in the assay, without the need to divide the sample into multiple different assays, Further, if more than one of the target sequences provides such a result, aggregation of these signals into a single dye channel may provide a stronger signal over background, providing more certainty for the assay result. During development of the methods described herein, it was surprisingly found that combining a large number of primers and flap assay probes for detecting multiple different target sequences, along with a shared FRET cassette, in a single amplification plus flap cleavage assay reaction did not increase background signal in no-target controls or in negative samples.


In some embodiments, different target sequences reporting to a single FRET cassette and single dye channel may not be from different marker genes or regions, but may be from different regions within a single marker (e.g., a single methylation marker gene). As described in Example 4, configuring assays to detect multiple regions of a single marker gene in an assay where all the regions report to a single dye, e.g., via a single FRET cassette, boosts the level of detectable signal from the copies of the target gene present in the reaction.


In yet other embodiments, the different target sequences to be detected may be a mixture of multiple regions of one marker, along with one or more regions of a different marker or markers. The different target sequences may comprise any combination of methylation markers, mutation markers, deletions, insertions, or any other manner of nucleic acid variants detectable in an assay such as a QuARTS amplification/flap cleavage assay.


In some embodiments, a marker is a region of 100 or fewer bases, the marker is a region of 500 or fewer bases, the marker is a region of 1000 or fewer bases, the marker is a region of 5000 or fewer bases, or, in some embodiments, the marker is one base. In some embodiments the marker is in a high CpG density promoter.


The technology is not limited by sample type. For example, in some embodiments the sample is a stool sample, a tissue sample, sputum, a blood sample (e.g., plasma, serum, whole blood), an excretion, or a urine sample.


Furthermore, the technology is not limited in the method used to determine methylation state. In some embodiments the assaying comprises using methylation specific polymerase chain reaction, nucleic acid sequencing, mass spectrometry, chip or array hybridization, methylation specific nuclease, mass-based separation, or target capture. In some embodiments, the assaying comprises use of a methylation specific oligonucleotide. In some embodiments, the technology uses massively parallel sequencing (e.g., next-generation sequencing) to determine methylation state, e.g., sequencing-by-synthesis, real-time (e.g., single-molecule) sequencing, bead emulsion sequencing, nanopore sequencing, etc.


The technology provides reagents for detecting a differentially methylated region (DMR). In some embodiments are provided an oligonucleotide comprising a sequence complementary to a chromosomal region having Kit embodiments are provided, e.g., a kit comprising a bisulfite reagent; and a control nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI and having a methylation state associated with a subject who does not have a cancer (e.g., colon cancer). In some embodiments, kits comprise a bisulfite reagent and an oligonucleotide as described herein. In some embodiments, kits comprise a bisulfite reagent; and a control nucleic acid comprising a sequence from such a chromosomal region and having a methylation state associated with a subject who has colon cancer.


The technology is related to embodiments of compositions (e.g., reaction mixtures). In some embodiments are provided a composition comprising a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ and a bisulfite reagent. Some embodiments provide a composition comprising a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI and an oligonucleotide as described herein. Some embodiments provide a composition comprising a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ and a methylation-sensitive restriction enzyme. Some embodiments provide a composition comprising a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ and a polymerase.


Additional related method embodiments are provided for screening for a neoplasm (e.g., colon carcinoma) in a sample obtained from a subject, e.g., a method comprising determining a methylation state of a marker in the sample comprising a base in a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI; comparing the methylation state of the marker from the subject sample to a methylation state of the marker from a normal control sample from a subject who does not have colon cancer; and determining a confidence interval and/or a p value of the difference in the methylation state of the subject sample and the normal control sample. In some embodiments, the confidence interval is 90%, 95%, 97.5%, 98%, 99%, 99.5%, 99.9% or 99.99% and the p value is 0.1, 0.05, 0.025, 0.02, 0.01, 0.005, 0.001, or 0.0001. Some embodiments of methods provide steps of reacting a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI with a bisulfite reagent to produce a bisulfite-reacted nucleic acid; sequencing the bisulfite-reacted nucleic acid to provide a nucleotide sequence of the bisulfite-reacted nucleic acid; comparing the nucleotide sequence of the bisulfite-reacted nucleic acid with a nucleotide sequence of a nucleic acid comprising the chromosomal region from a subject who does not have colon cancer to identify differences in the two sequences; and identifying the subject as having a neoplasm when a difference is present.


Systems for screening for colon cancer in a sample obtained from a subject are provided by the technology. Exemplary embodiments of systems include, e.g., a system for screening for colon cancer in a sample obtained from a subject, the system comprising an analysis component configured to determine the methylation state of a sample, a software component configured to compare the methylation state of the sample with a control sample or a reference sample methylation state recorded in a database, and an alert component configured to alert a user of a cancer-associated methylation state. An alert is determined in some embodiments by a software component that receives the results from multiple assays (e.g., determining the methylation states of multiple markers, e.g., a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI and calculating a value or result to report based on the multiple results. Some embodiments provide a database of weighted parameters associated with each chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI provided herein for use in calculating a value or result and/or an alert to report to a user (e.g., such as a physician, nurse, clinician, etc.). In some embodiments all results from multiple assays are reported and in some embodiments one or more results are used to provide a score, value, or result based on a composite of one or more results from multiple assays that is indicative of a colon cancer risk in a subject.


In some embodiments of systems, a sample comprises a nucleic acid comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ. In some embodiments the system further comprises a component for isolating a nucleic acid, a component for collecting a sample such as a component for collecting a stool sample. In some embodiments, the system comprises nucleic acid sequences comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKL In some embodiments the database comprises nucleic acid sequences from subjects who do not have colon cancer. Also provided are nucleic acids, e.g., a set of nucleic acids, each nucleic acid having a sequence comprising a chromosomal region having an annotation selected from VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ.


Related system embodiments comprise a set of nucleic acids as described and a database of nucleic acid sequences associated with the set of nucleic acids. Some embodiments further comprise a bisulfite reagent and some embodiments further comprise a nucleic acid sequencer.


In certain embodiments, methods for characterizing a sample obtained from a human subject are provided, comprising a) obtaining a sample from a human subject; b) assaying a methylation state of one or more markers in the sample, wherein the marker comprises a base in a chromosomal region having an annotation selected from the following groups of markers: VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKJ; and c) comparing the methylation state of the assayed marker to the methylation state of the marker assayed in a subject that does not have a neoplasm.


In some embodiments, the technology is related to assessing the presence of and methylation state of one or more of the markers identified herein in a biological sample. These markers comprise one or more differentially methylated regions (DMR) as discussed herein. Methylation state is assessed in embodiments of the technology. As such, the technology provided herein is not restricted in the method by which a gene's methylation state is measured. For example, in some embodiments the methylation state is measured by a genome scanning method. For example, one method involves restriction landmark genomic scanning (Kawai et al. (1994) Mol. Cell. Biol. 14: 7421-7427) and another example involves methylation-sensitive arbitrarily primed PCR (Gonzalgo et al. (1997) Cancer Res. 57: 594-599). In some embodiments, changes in methylation patterns at specific CpG sites are monitored by digestion of genomic DNA with methylation-sensitive restriction enzymes followed by Southern analysis of the regions of interest (digestion-Southern method). In some embodiments, analyzing changes in methylation patterns involves a PCR-based process that involves digestion of genomic DNA with methylation-sensitive restriction enzymes prior to PCR amplification (Singer-Sam et al. (1990) Nucl. Acids Res. 18: 687). In addition, other techniques have been reported that utilize bisulfite treatment of DNA as a starting point for methylation analysis. These include methylation-specific PCR (MSP) (Herman et al. (1992) Proc. Natl. Acad. Sci. USA 93: 9821-9826) and restriction enzyme digestion of PCR products amplified from bisulfite-converted DNA (Sadri and Hornsby (1996) Nucl. Acids Res. 24: 5058-5059; and Xiong and Laird (1997) Nucl. Acids Res. 25: 2532-2534). PCR techniques have been developed for detection of gene mutations (Kuppuswamy et al. (1991) Proc. Natl. Acad. Sci. USA 88: 1143-1147) and quantification of allelic-specific expression (Szabo and Mann (1995) Genes Dev. 9: 3097-3108; and Singer-Sam et al. (1992) PCR Methods Appl. 1: 160-163). Such techniques use internal primers, which anneal to a PCR-generated template and terminate immediately 5′ of the single nucleotide to be assayed. Methods using a “quantitative Ms-SNuPE assay” as described in U.S. Pat. No. 7,037,650 are used in some embodiments.


Upon evaluating a methylation state, the methylation state is often expressed as the fraction or percentage of individual strands of DNA that is methylated at a particular site (e.g., at a single nucleotide, at a particular region or locus, at a longer sequence of interest, e.g., up to a ˜100-bp, 200-bp, 500-bp, 1000-bp subsequence of a DNA or longer) relative to the total population of DNA in the sample comprising that particular site. Traditionally, the amount of the unmethylated nucleic acid is determined by PCR using calibrators. Then, a known amount of DNA is bisulfite treated and the resulting methylation-specific sequence is determined using either a real-time PCR or other exponential amplification, e.g., a QuARTS assay (e.g., as provided by U.S. Pat. Nos. 8,361,720; 8,715,937; 8,916,344; and 9,212,392).


For example, in some embodiments methods comprise generating a standard curve for the unmethylated target by using external standards. The standard curve is constructed from at least two points and relates the real-time Ct value for unmethylated DNA to known quantitative standards. Then, a second standard curve for the methylated target is constructed from at least two points and external standards. This second standard curve relates the Ct for methylated DNA to known quantitative standards. Next, the test sample Ct values are determined for the methylated and unmethylated populations and the genomic equivalents of DNA are calculated from the standard curves produced by the first two steps. The percentage of methylation at the site of interest is calculated from the amount of methylated DNAs relative to the total amount of DNAs in the population, e.g., (number of methylated DNAs)/(the number of methylated DNAs+number of unmethylated DNAs)×100.


Also provided herein are compositions and kits for practicing the methods. For example, in some embodiments, reagents (e.g., primers, probes) specific for one or more markers are provided alone or in sets (e.g., sets of primer pairs for amplifying a plurality of markers). Additional reagents for conducting a detection assay may also be provided (e.g., enzymes, buffers, positive and negative controls for conducting QuARTS, PCR, sequencing, bisulfite, or other assays). In some embodiments, the kits containing one or more reagents necessary, sufficient, or useful for conducting a method are provided. Also provided are reactions mixtures containing the reagents. Further provided are master mix reagent sets containing a plurality of reagents that may be added to each other and/or to a test sample to complete a reaction mixture.


Methods for isolating DNA suitable for these assay technologies are known in the art. In particular, some embodiments comprise isolation of nucleic acids as described in U.S. Pat. 9,000,146, which is incorporated herein by reference in its entirety.


Genomic DNA may be isolated by any means, including the use of commercially available kits. Briefly, wherein the DNA of interest is encapsulated by a cellular membrane the biological sample must be disrupted and lysed by enzymatic, chemical, or mechanical means. The DNA solution may then be cleared of proteins and other contaminants, e.g., by digestion with proteinase K. The genomic DNA is then recovered from the solution. This may be carried out by means of a variety of methods including salting out, organic extraction, or binding of the DNA to a solid phase support. The choice of method will be affected by several factors including time, expense, and required quantity of DNA. All clinical sample types comprising neoplastic matter or pre-neoplastic matter are suitable for use in the present method, e.g., cell lines, histological slides, biopsies, paraffin-embedded tissue, body fluids, stool, colonic effluent, urine, blood plasma, blood serum, whole blood, isolated blood cells, cells isolated from the blood, and combinations thereof.


The technology is not limited in the methods used to prepare the samples and provide a nucleic acid for testing. For example, in some embodiments, a DNA is isolated from a stool sample or from blood or from a plasma sample using direct gene capture, e.g., as detailed in U.S. Pat. Nos. 8,808,990 or 9,000,146, or by a related method. In some embodiments, a DNA is isolated from cells collected using an ingestible cell sampling device.


I. Methylation Assays to Detect Colon Cancer

Candidate methylated DNA markers were identified by unbiased whole methylome sequencing of selected colon cancer case and colon control tissues. The top marker candidates were further evaluated in 89 cancer and 95 normal plasma samples. DNA extracted from patient tissue samples was bisulfite treated and then candidate markers and reference genes (e.g., (3-actin or B3GALT6) as a normalizing genes were assayed by Quantitative Allele-Specific Real-time Target and Signal amplification (QuARTS amplification). QuARTS assay chemistry yields high discrimination for methylated marker selection and screening.


On receiver operator characteristics analyses of individual marker candidates, areas under the curve (AUCs) ranged from 0.63 to 0.75. At 92.6% specificity, a combined panel of 12 methylation markers (VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, and QKI) plus an assay for the CEA protein yielded a sensitivity of 67.4% across all stages of colon cancer.


II. Methylation Detection Assays and Kits

The markers described herein find use in a variety of methylation detection assays. The most frequently used method for analyzing a nucleic acid for the presence of 5-methylcytosine is based upon the bisulfite method described by Frommer, et al. for the detection of 5-methylcytosines in DNA (Frommer et al. (1992) Proc. Natl. Acad. Sci. USA 89: 1827-31 explicitly incorporated herein by reference in its entirety for all purposes) or variations thereof. The bisulfite method of mapping 5-methylcytosines is based on the observation that cytosine, but not 5-methylcytosine, reacts with hydrogen sulfite ion (also known as bisulfite). The reaction is usually performed according to the following steps: first, cytosine reacts with hydrogen sulfite to form a sulfonated cytosine. Next, spontaneous deamination of the sulfonated reaction intermediate results in a sulfonated uracil. Finally, the sulfonated uracil is desulfonated under alkaline conditions to form uracil. Detection is possible because uracil base pairs with adenine (thus behaving like thymine), whereas 5-methylcytosine base pairs with guanine (thus behaving like cytosine). This makes the discrimination of methylated cytosines from non-methylated cytosines possible by, e.g., bisulfite genomic sequencing (Grigg G, & Clark S, Bioessays (1994) 16: 431-36; Grigg G, DNA Seq. (1996) 6: 189-98),methylation-specific PCR (MSP) as is disclosed, e.g., in U.S. Pat. No. 5,786,146, or using an assay comprising sequence-specific probe cleavage, e.g., a QuARTS flap endonuclease assay (see, e.g., Zou et al. (2010) “Sensitive quantification of methylated markers with a novel methylation specific technology” Clin Chem 56: A199; and in U.S. Pat. Nos. 8,361,720; 8,715,937; 8,916,344; and 9,212,392.


Some conventional technologies are related to methods comprising enclosing the DNA to be analyzed in an agarose matrix, thereby preventing the diffusion and renaturation of the DNA (bisulfite only reacts with single-stranded DNA), and replacing precipitation and purification steps with a fast dialysis (Olek A, et al. (1996) “A modified and improved method for bisulfite-based cytosine methylation analysis” Nucleic Acids Res. 24: 5064-6). It is thus possible to analyze individual cells for methylation status, illustrating the utility and sensitivity of the method. An overview of conventional methods for detecting 5-methylcytosine is provided by Rein, T., et al. (1998) Nucleic Acids Res. 26: 2255.


The bisulfite technique typically involves amplifying short, specific fragments of a known nucleic acid subsequent to a bisulfite treatment, then either assaying the product by sequencing (Olek & Walter (1997) Nat. Genet. 17: 275-6) or a primer extension reaction (Gonzalgo & Jones (1997) Nucleic Acids Res. 25: 2529-31; WO 95/00669; U.S. Pat. No. 6,251,594) to analyze individual cytosine positions. Some methods use enzymatic digestion (Xiong & Laird (1997) Nucleic Acids Res. 25: 2532-4). Detection by hybridization has also been described in the art (Olek et al., WO 99/28498). Additionally, use of the bisulfite technique for methylation detection with respect to individual genes has been described (Grigg & Clark (1994) Bioessays 16: 431-6,; Zeschnigk et al. (1997) Hum Mol Genet. 6: 387-95; Feil et al. (1994) Nucleic Acids Res. 22: 695; Martin et al. (1995) Gene 157: 261-4; WO 9746705; WO 9515373).


Various methylation assay procedures can be used in conjunction with bisulfite treatment according to the present technology. These assays allow for determination of the methylation state of one or a plurality of CpG dinucleotides (e.g., CpG islands) within a nucleic acid sequence. Such assays involve, among other techniques, sequencing of bisulfite-treated nucleic acid, PCR (for sequence-specific amplification), Southern blot analysis, and use of methylation-sensitive restriction enzymes.


For example, genomic sequencing has been simplified for analysis of methylation patterns and 5-methylcytosine distributions by using bisulfite treatment (Frommer et al. (1992) Proc. Natl. Acad. Sci. USA 89: 1827-1831). Additionally, restriction enzyme digestion of PCR products amplified from bisulfite-converted DNA finds use in assessing methylation state, e.g., as described by Sadri & Hornsby (1997) Nucl. Acids Res. 24: 5058-5059 or as embodied in the method known as COBRA (Combined Bisulfite Restriction Analysis) (Xiong & Laird (1997) Nucleic Acids Res. 25: 2532-2534).


COBRA™ analysis is a quantitative methylation assay useful for determining DNA methylation levels at specific loci in small amounts of genomic DNA (Xiong & Laird, Nucleic


Acids Res. 25:2532-2534, 1997). Briefly, restriction enzyme digestion is used to reveal methylation-dependent sequence differences in PCR products of sodium bisulfite-treated DNA. Methylation-dependent sequence differences are first introduced into the genomic DNA by standard bisulfite treatment according to the procedure described by Frommer et al. (Proc. Natl. Acad. Sci. USA 89:1827-1831, 1992). PCR amplification of the bisulfite converted DNA is then performed using primers specific for the CpG islands of interest, followed by restriction endonuclease digestion, gel electrophoresis, and detection using specific, labeled hybridization probes. Methylation levels in the original DNA sample are represented by the relative amounts of digested and undigested PCR product in a linearly quantitative fashion across a wide spectrum of DNA methylation levels. In addition, this technique can be reliably applied to DNA obtained from microdissected paraffin-embedded tissue samples.


Typical reagents (e.g., as might be found in a typical COBRA™-based kit) for COBRA™ analysis may include, but are not limited to: PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, etc.); restriction enzyme and appropriate buffer; gene-hybridization oligonucleotide; control hybridization oligonucleotide; kinase labeling kit for oligonucleotide probe; and labeled nucleotides. Additionally, bisulfite conversion reagents may include: DNA denaturation buffer; sulfonation buffer; DNA recovery reagents or kits (e.g., precipitation, ultrafiltration, affinity column); desulfonation buffer; and DNA recovery components.


Assays such as “MethyLight™” (a fluorescence-based real-time PCR technique) (Eads et al., Cancer Res. 59:2302-2306, 1999), Ms-SNuPE™ (Methylation-sensitive Single Nucleotide Primer Extension) reactions (Gonzalgo & Jones, Nucleic Acids Res. 25:2529-2531, 1997), methylation-specific PCR (“MSP”; Herman et al., Proc. Natl. Acad. Sci. USA 93:9821-9826, 1996; U.S. Pat. No. 5,786,146), and methylated CpG island amplification (“MCA”; Toyota et al., Cancer Res. 59:2307-12, 1999) are used alone or in combination with one or more of these methods.


The “HeavyMethyl™” assay, technique is a quantitative method for assessing methylation differences based on methylation-specific amplification of bisulfite-treated DNA. Methylation-specific blocking probes (“blockers”) covering CpG positions between, or covered by, the amplification primers enable methylation-specific selective amplification of a nucleic acid sample.


The term “HeavyMethyl™ MethyLight™” assay refers to a HeavyMethyl™ MethyLight™ assay, which is a variation of the MethyLight™ assay, wherein the MethyLight™ assay is combined with methylation specific blocking probes covering CpG positions between the amplification primers. The HeavyMethyl™ assay may also be used in combination with methylation specific amplification primers.


Typical reagents (e.g., as might be found in a typical MethyLight™-based kit) for HeavyMethyl™ analysis may include, but are not limited to: PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, or bisulfite treated DNA sequence or CpG island, etc.); blocking oligonucleotides; optimized PCR buffers and deoxynucleotides; and Taq polymerase.


MSP (methylation-specific PCR) allows for assessing the methylation status of virtually any group of CpG sites within a CpG island, independent of the use of methylation-sensitive restriction enzymes (Herman et al. Proc. Natl. Acad. Sci. USA 93:9821-9826, 1996; U.S. Pat. No. 5,786,146). Briefly, DNA is modified by sodium bisulfite, which converts unmethylated, but not methylated cytosines, to uracil, and the products are subsequently amplified with primers specific for methylated versus unmethylated DNA. MSP requires only small quantities of DNA, is sensitive to 0.1% methylated alleles of a given CpG island locus, and can be performed on DNA extracted from paraffin-embedded samples. Typical reagents (e.g., as might be found in a typical MSP-based kit) for MSP analysis may include, but are not limited to: methylated and unmethylated PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, etc.); optimized PCR buffers and deoxynucleotides, and specific probes.


The MethyLight™ assay is a high-throughput quantitative methylation assay that utilizes fluorescence-based real-time PCR (e.g., TaqMan®) that requires no further manipulations after the PCR step (Eads et al., Cancer Res. 59:2302-2306, 1999). Briefly, the MethyLight™ process begins with a mixed sample of genomic DNA that is converted, in a sodium bisulfite reaction, to a mixed pool of methylation-dependent sequence differences according to standard procedures (the bisulfite process converts unmethylated cytosine residues to uracil). Fluorescence-based PCR is then performed in a “biased” reaction, e.g., with PCR primers that overlap known CpG dinucleotides. Sequence discrimination occurs both at the level of the amplification process and at the level of the fluorescence detection process.


The MethyLight™ assay is used as a quantitative test for methylation patterns in a nucleic acid, e.g., a genomic DNA sample, wherein sequence discrimination occurs at the level of probe hybridization. In a quantitative version, the PCR reaction provides for a methylation specific amplification in the presence of a fluorescent probe that overlaps a particular putative methylation site. An unbiased control for the amount of input DNA is provided by a reaction in which neither the primers, nor the probe, overlie any CpG dinucleotides. Alternatively, a qualitative test for genomic methylation is achieved by probing the biased PCR pool with either control oligonucleotides that do not cover known methylation sites (e.g., a fluorescence-based version of the HeavyMethyl™ and MSP techniques) or with oligonucleotides covering potential methylation sites.


The MethyLight™ process is used with any suitable probe (e.g. a “TaqMan®” probe, a Lightcycler® probe, etc.) For example, in some applications double-stranded genomic DNA is treated with sodium bisulfite and subjected to one of two sets of PCR reactions using TaqMan® probes, e.g., with MSP primers and/or HeavyMethyl blocker oligonucleotides and a TaqMan® probe. The TaqMan® probe is dual-labeled with fluorescent “reporter” and “quencher” molecules and is designed to be specific for a relatively high GC content region so that it melts at about a 10° C. higher temperature in the PCR cycle than the forward or reverse primers. This allows the TaqMan® probe to remain fully hybridized during the PCR annealing/extension step.


As the Taq polymerase enzymatically synthesizes a new strand during PCR, it will eventually reach the annealed TaqMan® probe. The Taq polymerase 5′ to 3′ endonuclease activity will then displace the TaqMan® probe by digesting it to release the fluorescent reporter molecule for quantitative detection of its now unquenched signal using a real-time fluorescent detection system.


Typical reagents (e.g., as might be found in a typical MethyLight™-based kit) for MethyLight™ analysis may include, but are not limited to: PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, etc.); TaqMan® or Lightcycler® probes; optimized PCR buffers and deoxynucleotides; and Taq polymerase.


The QM™ (quantitative methylation) assay is an alternative quantitative test for methylation patterns in genomic DNA samples, wherein sequence discrimination occurs at the level of probe hybridization. In this quantitative version, the PCR reaction provides for unbiased amplification in the presence of a fluorescent probe that overlaps a particular putative methylation site. An unbiased control for the amount of input DNA is provided by a reaction in which neither the primers, nor the probe, overlie any CpG dinucleotides. Alternatively, a qualitative test for genomic methylation is achieved by probing the biased PCR pool with either control oligonucleotides that do not cover known methylation sites (a fluorescence-based version of the HeavyMethyl™ and MSP techniques) or with oligonucleotides covering potential methylation sites.


The QM™ process can be used with any suitable probe, e.g., “TaqMan®” probes, Lightcycler® probes, in the amplification process. For example, double-stranded genomic DNA is treated with sodium bisulfite and subjected to unbiased primers and the TaqMan® probe. The TaqMan® probe is dual-labeled with fluorescent “reporter” and “quencher” molecules, and is designed to be specific for a relatively high GC content region so that it melts out at about a 10° C. higher temperature in the PCR cycle than the forward or reverse primers. This allows the TaqMan® probe to remain fully hybridized during the PCR annealing/extension step. As the Taq polymerase enzymatically synthesizes a new strand during PCR, it will eventually reach the annealed TaqMan® probe. The Taq polymerase 5′ to 3′ endonuclease activity will then displace the TaqMan® probe by digesting it to release the fluorescent reporter molecule for quantitative detection of its now unquenched signal using a real-time fluorescent detection system. Typical reagents (e.g., as might be found in a typical QM™-based kit) for QM™ analysis may include, but are not limited to: PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, etc.); TaqMan® or Lightcycler® probes; optimized PCR buffers and deoxynucleotides; and Taq polymerase.


The Ms-SNuPE™ technique is a quantitative method for assessing methylation differences at specific CpG sites based on bisulfate treatment of DNA, followed by single-nucleotide primer extension (Gonzalgo & Jones, Nucleic Acids Res. 25:2529-2531, 1997). Briefly, genomic DNA is reacted with sodium bisulfite to convert unmethylated cytosine to uracil while leaving 5-methylcytosine unchanged. Amplification of the desired target sequence is then performed using PCR primers specific for bisulfite-converted DNA, and the resulting product is isolated and used as a template for methylation analysis at the CpG site of interest.


Small amounts of DNA can be analyzed (e.g., microdissected pathology sections) and it avoids utilization of restriction enzymes for determining the methylation status at CpG sites.


Typical reagents (e.g., as might be found in a typical Ms-SNuPE™-based kit) for Ms-SNuPE™ analysis may include, but are not limited to: PCR primers for specific loci (e.g., specific genes, markers, regions of genes, regions of markers, bisulfite treated DNA sequence, CpG island, etc.); optimized PCR buffers and deoxynucleotides; gel extraction kit; positive control primers; Ms-SNuPE™ primers for specific loci; reaction buffer (for the Ms-SNuPE reaction); and labeled nucleotides. Additionally, bisulfite conversion reagents may include: DNA denaturation buffer; sulfonation buffer; DNA recovery reagents or kit (e.g., precipitation, ultrafiltration, affinity column); desulfonation buffer; and DNA recovery components.


Reduced Representation Bisulfite Sequencing (RRBS) begins with bisulfite treatment of nucleic acid to convert all unmethylated cytosines to uracil, followed by restriction enzyme digestion (e.g., by an enzyme that recognizes a site including a CG sequence such as MspI) and complete sequencing of fragments after coupling to an adapter ligand. The choice of restriction enzyme enriches the fragments for CpG dense regions, reducing the number of redundant sequences that may map to multiple gene positions during analysis. As such, RRBS reduces the complexity of the nucleic acid sample by selecting a subset (e.g., by size selection using preparative gel electrophoresis) of restriction fragments for sequencing. As opposed to whole-genome bisulfite sequencing, every fragment produced by the restriction enzyme digestion contains DNA methylation information for at least one CpG dinucleotide. As such, RRBS enriches the sample for promoters, CpG islands, and other genomic features with a high frequency of restriction enzyme cut sites in these regions and thus provides an assay to assess the methylation state of one or more genomic loci.


A typical protocol for RRBS comprises the steps of digesting a nucleic acid sample with a restriction enzyme such as MspI, filling in overhangs and A-tailing, ligating adaptors, bisulfite conversion, and PCR. See, e.g., et al. (2005) “Genome-scale DNA methylation mapping of clinical samples at single-nucleotide resolution” Nat Methods 7: 133-6; Meissner et al. (2005) “Reduced representation bisulfite sequencing for comparative high-resolution DNA methylation analysis” Nucleic Acids Res. 33: 5868-77.


In some embodiments, a quantitative allele-specific real-time target and signal amplification (QuARTS) assay is used to evaluate methylation state. Three reactions sequentially occur in each QuARTS assay, including amplification (reaction 1) and target probe cleavage (reaction 2) in the primary reaction; and FRET cleavage and fluorescent signal generation (reaction 3) in the secondary reaction. When target nucleic acid is amplified with specific primers, a specific detection probe with a flap sequence loosely binds to the amplicon. The presence of the specific invasive oligonucleotide at the target binding site causes a 5′ nuclease, e.g., a FEN-1 endonuclease, to release the flap sequence by cutting between the detection probe and the flap sequence. The flap sequence is complementary to a non-hairpin portion of a corresponding FRET cassette. Accordingly, the flap sequence functions as an invasive oligonucleotide on the FRET cassette and effects a cleavage between the FRET cassette fluorophore and a quencher, which produces a fluorescent signal. The cleavage reaction can cut multiple probes per target and thus release multiple fluorophore per flap, providing exponential signal amplification. QuARTS can detect multiple targets in a single reaction well by using FRET cassettes with different dyes. See, e.g., in Zou et al. (2010) “Sensitive quantification of methylated markers with a novel methylation specific technology” Clin Chem 56: A199). In embodiments, described herein, the QuARTS assay can also be configured to detect multiple different targets in or different regions of the same target using the same FRET cassette, producing an additive fluorescence signal from a single dye.


In some embodiments, the bisulfite-treated DNA is purified prior to the quantification. This may be conducted by any means known in the art, such as but not limited to ultrafiltration, e.g., by means of Microcon™ columns (manufactured by Millipore™). The purification is carried out according to a modified manufacturer's protocol (see, e.g., PCT/EP2004/011715, which is incorporated by reference in its entirety). In some embodiments, the bisulfite treated DNA is bound to a solid support, e.g., a magnetic bead, and desulfonation and washing occurs while the DNA is bound to the support. Examples of such embodiments are provided, e.g., in WO 2013/116375. In certain preferred embodiments, support-bound DNA is ready for a methylation assay immediately after desulfonation and washing on the support. In some embodiments, the desulfonated DNA is eluted from the support prior to assay.


In some embodiments, fragments of the treated DNA are amplified using sets of primer oligonucleotides according to the present invention (e.g., see FIG. 1) and an amplification enzyme. The amplification of several DNA segments can be carried out simultaneously in one and the same reaction vessel. Typically, the amplification is carried out using a polymerase chain reaction (PCR).


Methods for isolating DNA suitable for these assay technologies are known in the art. In particular, some embodiments comprise isolation of nucleic acids as described in U.S. patent application Ser. No. 13/470,251 (“Isolation of Nucleic Acids”, published as US 2012/0288868), incorporated herein by reference in its entirety.


In some embodiments, the markers described herein find use in QUARTS assays performed on stool samples. In some embodiments, methods for producing DNA samples and, in particular, to methods for producing DNA samples that comprise highly purified, low-abundance nucleic acids in a small volume (e.g., less than 100, less than 60 microliters) and that are substantially and/or effectively free of substances that inhibit assays used to test the DNA samples (e.g., PCR, INVADER, QuARTS assays, etc.) are provided. Such DNA samples find use in diagnostic assays that qualitatively detect the presence of, or quantitatively measure the activity, expression, or amount of, a gene, a gene variant (e.g., an allele), or a gene modification (e.g., methylation) present in a sample taken from a patient. For example, some cancers are correlated with the presence of particular mutant alleles or particular methylation states, and thus detecting and/or quantifying such mutant alleles or methylation states has predictive value in the diagnosis and treatment of cancer.


Many valuable genetic markers are present in extremely low amounts in samples and many of the events that produce such markers are rare. Consequently, even sensitive detection methods such as PCR require a large amount of DNA to provide enough of a low-abundance target to meet or supersede the detection threshold of the assay. Moreover, the presence of even low amounts of inhibitory substances compromise the accuracy and precision of these assays directed to detecting such low amounts of a target. Accordingly, provided herein are methods providing the requisite management of volume and concentration to produce such DNA samples.


In some embodiments, the sample comprises blood, serum, plasma, or saliva. In some embodiments, the subject is human. Such samples can be obtained by any number of means known in the art, such as will be apparent to the skilled person. Cell free or substantially cell free samples can be obtained by subjecting the sample to various techniques known to those of skill in the art which include, but are not limited to, centrifugation and filtration. Although it is generally preferred that no invasive techniques are used to obtain the sample, it still may be preferable to obtain samples such as tissue homogenates, tissue sections, and biopsy specimens. The technology is not limited in the methods used to prepare the samples and provide a nucleic acid for testing. For example, in some embodiments, a DNA is isolated from a stool sample or from blood or from a plasma sample using direct gene capture, e.g., as detailed in U.S. Pat. Nos. 8,808,990 and 9,169,511, and in WO 2012/155072, or by a related method.


The analysis of markers can be carried out separately or simultaneously with additional markers within one test sample. For example, several markers can be combined into one test for efficient processing of multiple samples and for potentially providing greater diagnostic and/or prognostic accuracy. In addition, one skilled in the art would recognize the value of testing multiple samples (for example, at successive time points) from the same subject. Such testing of serial samples can allow the identification of changes in marker methylation states over time. Changes in methylation state, as well as the absence of change in methylation state, can provide useful information about the disease status that includes, but is not limited to, identifying the approximate time from onset of the event, the presence and amount of salvageable tissue, the appropriateness of drug therapies, the effectiveness of various therapies, and identification of the subject's outcome, including risk of future events.


The analysis of biomarkers can be carried out in a variety of physical formats. For example, the use of microtiter plates or automation can be used to facilitate the processing of large numbers of test samples. Alternatively, single sample formats could be developed to facilitate immediate treatment and diagnosis in a timely fashion, for example, in ambulatory transport or emergency room settings.


It is contemplated that embodiments of the technology are provided in the form of a kit. The kits comprise embodiments of the compositions, devices, apparatuses, etc. described herein, and instructions for use of the kit. Such instructions describe appropriate methods for preparing an analyte from a sample, e.g., for collecting a sample and preparing a nucleic acid from the sample. Individual components of the kit are packaged in appropriate containers and packaging (e.g., vials, boxes, blister packs, ampules, jars, bottles, tubes, and the like) and the components are packaged together in an appropriate container (e.g., a box or boxes) for convenient storage, shipping, and/or use by the user of the kit. It is understood that liquid components (e.g., a buffer) may be provided in a lyophilized form to be reconstituted by the user. Kits may include a control or reference for assessing, validating, and/or assuring the performance of the kit. For example, a kit for assaying the amount of a nucleic acid present in a sample may include a control comprising a known concentration of the same or another nucleic acid for comparison and, in some embodiments, a detection reagent (e.g., a primer) specific for the control nucleic acid. The kits are appropriate for use in a clinical setting and, in some embodiments, for use in a user's home. The components of a kit, in some embodiments, provide the functionalities of a system for preparing a nucleic acid solution from a sample. In some embodiments, certain components of the system are provided by the user.


In some embodiments the technology relates to the analysis of any sample associated with colon cancer. For example, in some embodiments the sample comprises a tissue and/or biological fluid obtained from a patient. In some embodiments, the sample comprises a secretion. In some embodiments, the sample comprises sputum, blood, serum, plasma, gastric secretions, colon tissue samples, colon cells or colon DNA recovered from stool. In some embodiments, the subject is human. Such samples can be obtained by any number of means known in the art, such as will be apparent to the skilled person.


In some embodiments, diagnostic assays identify the presence of a disease or condition in an individual. In some embodiments, the disease is cancer (e.g., colon cancer). In some embodiments, markers whose aberrant methylation is associated with a colon cancer (e.g., one or more markers selected from the markers listed in Table 1, or preferably one or more of VAV3; ZNF671; CHST2; FLI1; JAM3; SFMBT2; PDGFD; DTX1; TSPYL5; ZNF568; GRIN2D, QKI, FER1L4) are used. In some embodiments, an assay further comprises detection of a reference gene (e.g., (3-actin, ZDHHC1, B3GALT6).


In some embodiments, the technology finds application in treating a patient (e.g., a patient with colon cancer, with early-stage colon cancer, or who may develop colon cancer), the method comprising determining the methylation state of one or more markers as provided herein and administering a treatment to the patient based on the results of determining the methylation state. The treatment may be administration of a pharmaceutical compound, a vaccine, performing a surgery, imaging the patient, performing another test. Preferably, said use is in a method of clinical screening, a method of prognosis assessment, a method of monitoring the results of therapy, a method to identify patients most likely to respond to a particular therapeutic treatment, a method of imaging a patient or subject, and a method for drug screening and development.


In some embodiments, the technology finds application in methods for diagnosing colon cancer in a subject. The terms “diagnosing” and “diagnosis” as used herein refer to methods by which the skilled artisan can estimate and even determine whether or not a subject is suffering from a given disease or condition or may develop a given disease or condition in the future. The skilled artisan often makes a diagnosis on the basis of one or more diagnostic indicators, such as for example a biomarker, the methylation state of which is indicative of the presence, severity, or absence of the condition.


Along with diagnosis, clinical cancer prognosis relates to determining the aggressiveness of the cancer and the likelihood of tumor recurrence to plan the most effective therapy. If a more accurate prognosis can be made or even a potential risk for developing the cancer can be assessed, appropriate therapy, and in some instances less severe therapy for the patient can be chosen. Assessment (e.g., determining methylation state) of cancer biomarkers is useful to separate subjects with good prognosis and/or low risk of developing cancer who will need no therapy or limited therapy from those more likely to develop cancer or suffer a recurrence of cancer who might benefit from more intensive treatments.


As such, “making a diagnosis” or “diagnosing”, as used herein, is further inclusive of making a determination of a risk of developing cancer or determining a prognosis, which can provide for predicting a clinical outcome (with or without medical treatment), selecting an appropriate treatment (or whether treatment would be effective), or monitoring a current treatment and potentially changing the treatment, based on the measure of the diagnostic biomarkers disclosed herein.


Further, in some embodiments of the technology, multiple determinations of the biomarkers over time can be made to facilitate diagnosis and/or prognosis. A temporal change in the biomarker can be used to predict a clinical outcome, monitor the progression of colon cancer, and/or monitor the efficacy of appropriate therapies directed against the cancer. In such an embodiment for example, one might expect to see a change in the methylation state of one or more biomarkers disclosed herein (and potentially one or more additional biomarker(s), if monitored) in a biological sample over time during the course of an effective therapy.


The technology further finds application in methods for determining whether to initiate or continue prophylaxis or treatment of a cancer in a subject. In some embodiments, the method comprises providing a series of biological samples over a time period from the subject; analyzing the series of biological samples to determine a methylation state of at least one biomarker disclosed herein in each of the biological samples; and comparing any measurable change in the methylation states of one or more of the biomarkers in each of the biological samples. Any changes in the methylation states of biomarkers over the time period can be used to predict risk of developing cancer, predict clinical outcome, determine whether to initiate or continue the prophylaxis or therapy of the cancer, and whether a current therapy is effectively treating the cancer. For example, a first time point can be selected prior to initiation of a treatment and a second time point can be selected at some time after initiation of the treatment. Methylation states can be measured in each of the samples taken from different time points and qualitative and/or quantitative differences noted. A change in the methylation states of the biomarker levels from the different samples can be correlated with risk for developing colon, prognosis, determining treatment efficacy, and/or progression of the cancer in the subject.


In preferred embodiments, the methods and compositions of the invention are for treatment or diagnosis of disease at an early stage, for example, before symptoms of the disease appear. In some embodiments, the methods and compositions of the invention are for treatment or diagnosis of disease at a clinical stage.


As noted above, in some embodiments multiple determinations of one or more diagnostic or prognostic biomarkers can be made, and a temporal change in the marker can be used to determine a diagnosis or prognosis. For example, a diagnostic marker can be determined at an initial time, and again at a second time. In such embodiments, an increase in the marker from the initial time to the second time can be diagnostic of a particular type or severity of cancer, or a given prognosis. Likewise, a decrease in the marker from the initial time to the second time can be indicative of a particular type or severity of cancer, or a given prognosis. Furthermore, the degree of change of one or more markers can be related to the severity of the cancer and future adverse events. The skilled artisan will understand that, while in certain embodiments comparative measurements can be made of the same biomarker at multiple time points, one can also measure a given biomarker at one time point, and a second biomarker at a second time point, and a comparison of these markers can provide diagnostic information.


As used herein, the phrase “determining the prognosis” refers to methods by which the skilled artisan can predict the course or outcome of a condition in a subject. The term “prognosis” does not refer to the ability to predict the course or outcome of a condition with 100% accuracy, or even that a given course or outcome is predictably more or less likely to occur based on the methylation state of a biomarker. Instead, the skilled artisan will understand that the term “prognosis” refers to an increased probability that a certain course or outcome will occur; that is, that a course or outcome is more likely to occur in a subject exhibiting a given condition, when compared to those individuals not exhibiting the condition. For example, in individuals not exhibiting the condition, the chance of a given outcome (e.g., suffering from colon cancer) may be very low.


In some embodiments, a statistical analysis associates a prognostic indicator with a predisposition to an adverse outcome. For example, in some embodiments, a methylation state different from that in a normal control sample obtained from a patient who does not have a cancer can signal that a subject is more likely to suffer from a cancer than subjects with a level that is more similar to the methylation state in the control sample, as determined by a level of statistical significance. Additionally, a change in methylation state from a baseline (e.g., “normal”) level can be reflective of subject prognosis, and the degree of change in methylation state can be related to the severity of adverse events. Statistical significance is often determined by comparing two or more populations and determining a confidence interval and/or ap value. See, e.g., Dowdy and Wearden, Statistics for Research, John Wiley & Sons, New York, 1983, incorporated herein by reference in its entirety. Exemplary confidence intervals of the present subject matter are 90%, 95%, 97.5%, 98%, 99%, 99.5%, 99.9% and 99.99%, while exemplary p values are 0.1, 0.05, 0.025, 0.02, 0.01, 0.005, 0.001, and 0.0001.


In other embodiments, a threshold degree of change in the methylation state of a prognostic or diagnostic biomarker disclosed herein can be established, and the degree of change in the methylation state of the biomarker in a biological sample is simply compared to the threshold degree of change in the methylation state. A preferred threshold change in the methylation state for biomarkers provided herein is about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 50%, about 75%, about 100%, and about 150%. In yet other embodiments, a “nomogram” can be established, by which a methylation state of a prognostic or diagnostic indicator (biomarker or combination of biomarkers) is directly related to an associated disposition towards a given outcome. The skilled artisan is acquainted with the use of such nomograms to relate two numeric values with the understanding that the uncertainty in this measurement is the same as the uncertainty in the marker concentration because individual sample measurements are referenced, not population averages.


In some embodiments, a control sample is analyzed concurrently with the biological sample, such that the results obtained from the biological sample can be compared to the results obtained from the control sample. Additionally, it is contemplated that standard curves can be provided, with which assay results for the biological sample may be compared. Such standard curves present methylation states of a biomarker as a function of assay units, e.g., fluorescent signal intensity, if a fluorescent label is used. Using samples taken from multiple donors, standard curves can be provided for control methylation states of the one or more biomarkers in normal tissue, as well as for “at-risk” levels of the one or more biomarkers in tissue taken from donors with colon cancer.


The analysis of markers can be carried out separately or simultaneously with additional markers within one test sample. For example, several markers can be combined into one test for efficient processing of a multiple of samples and for potentially providing greater diagnostic and/or prognostic accuracy. In addition, one skilled in the art would recognize the value of testing multiple samples (for example, at successive time points) from the same subject. Such testing of serial samples can allow the identification of changes in marker methylation states over time. Changes in methylation state, as well as the absence of change in methylation state, can provide useful information about the disease status that includes, but is not limited to, identifying the approximate time from onset of the event, the presence and amount of salvageable tissue, the appropriateness of drug therapies, the effectiveness of various therapies, and identification of the subject's outcome, including risk of future events.


The analysis of biomarkers can be carried out in a variety of physical formats. For example, the use of microtiter plates or automation can be used to facilitate the processing of large numbers of test samples. Alternatively, single sample formats could be developed to facilitate immediate treatment and diagnosis in a timely fashion, for example, in ambulatory transport or emergency room settings.


In some embodiments, the subject is diagnosed as having colon cancer if, when compared to a control methylation state, there is a measurable difference in the methylation state of at least one biomarker in the sample. Conversely, when no change in methylation state is identified in the biological sample, the subject can be identified as not having colon cancer, not being at risk for the cancer, or as having a low risk of the cancer. In this regard, subjects having colon cancer or risk thereof can be differentiated from subjects having low to substantially no cancer or risk thereof. Those subjects having a risk of developing colon cancer can be placed on a more intensive and/or regular screening schedule. On the other hand, those subjects having low to substantially no risk may avoid being subjected to screening procedures, until such time as a future screening, for example, a screening conducted in accordance with the present technology, indicates that a risk of colon cancer has appeared in those subjects.


As mentioned above, depending on the embodiment of the method of the present technology, detecting a change in methylation state of the one or more biomarkers can be a qualitative determination or it can be a quantitative determination. As such, the step of diagnosing a subject as having, or at risk of developing, colon cancer indicates that certain threshold measurements are made, e.g., the methylation state of the one or more biomarkers in the biological sample varies from a predetermined control methylation state. In some embodiments of the method, the control methylation state is any detectable methylation state of the biomarker. In other embodiments of the method where a control sample is tested concurrently with the biological sample, the predetermined methylation state is the methylation state in the control sample. In other embodiments of the method, the predetermined methylation state is based upon and/or identified by a standard curve. In other embodiments of the method, the predetermined methylation state is a specifically state or range of state. As such, the predetermined methylation state can be chosen, within acceptable limits that will be apparent to those skilled in the art, based in part on the embodiment of the method being practiced and the desired specificity, etc.


Over recent years, it has become apparent that circulating epithelial cells, representing metastatic tumor cells, can be detected in the blood of many patients with cancer. Molecular profiling of rare cells is important in biological and clinical studies. Applications range from characterization of circulating epithelial cells (CEpCs) in the peripheral blood of cancer patients for disease prognosis and personalized treatment (See e.g., Cristofanilli M, et al. (2004) N Engl J Med 351:781-791; Hayes D F, et al. (2006) Clin Cancer Res 12:4218-4224; Budd G T, et al., (2006) Clin Cancer Res 12:6403-6409; Moreno J G, et al. (2005) Urology 65:713-718; Pantel et al., (2008) Nat Rev 8:329-340; and Cohen S J, et al. (2008) J Clin Oncol 26:3213-3221). Accordingly, embodiments of the present disclosure provide compositions and methods for detecting the presence of metastatic cancer in a subject by identifying the presence of methylated markers in plasma or whole blood.


Esophageal Cell Samples

Exemplary nucleic acid assay designs are shown in FIG. 16A-16F. For example, esophageal cells may be harvested from the abrasive sponge and the levels of one or more biomarkers selected from ZNF682, NDRG4, and VAV3 may be determined. In some embodiments, levels of ZNF682, NDRG4, and VAV3 may be determined. In some embodiments, detecting an esophageal disorder may comprise measuring DNA methylation levels of the one or more biomarkers.


In some embodiments, the biomarker may be ZNF682. Exemplary primers and probes for ZNF682 are shown in FIG. 16. In some embodiments, the ZNF682 forward primer may comprise 5′AGTTTATTTTGGGAAGAGTCGCG3′ (SEQ ID NO: 190), the reverse primer may comprise 5′CCATTATCCCCGCAATCGAA3′ (SEQ ID NO: 191), and the probe may comprise 5′CGCGCCGAGGGCGCGTTTTTGCGTT/3C6/3′(SEQ ID NO: 192).


In some embodiments, the biomarker may be VAV3. Exemplary primers and probes for VAV3 are shown in FIG. 16. In some embodiments, the VAV3 forward primer may comprise 5′TCGGAGTCGAGTTTAGCGC3′ (SEQ ID NO: 108) and the reverse primer may comprise 5′CGAAATCGAAAAAACAAAAACCGC3′ (SEQ ID NO: 109). In some embodiments, VAV3 may be detected by one probe or two probes. For example, VAV3 may be detected by the probe (arm 1) 5′CGCCGAGGCGGCGTTCGCGA/3C6/3′ (SEQ ID NO: 110) and/or the probe (arm 5) 5′CCACGGACGCGGCGTTCGCGA/3C6/3′ (SEQ ID NO: 147).


In some embodiments, the biomarker may be NDRG4. Exemplary primers and probes for NDRG4 are shown in FIG. 16. In some embodiments, the NDRG4 forward primer may comprise 5′CGGTTTTCGTTCGTTTTTTCG3′ (SEQ ID NO: 185), the reverse primer may comprise 5′CCGCCTTCTACGCGACTA3′ (SEQ ID NO: 186), and the probe may comprise 5′CCACGGACGGTTCGTTTATCG/3C6/3′ (SEQ ID NO: 187).



FIG. 16 shows schematic diagrams of marker target regions in unconverted form and bisulfate-converted form. Flap assay primers and probes for detection of bisulfate-converted target DNA are shown.



FIG. 17 provides a table of nucleic acid sequences and corresponding SEQ ID NOS.


In some embodiments, the one or more biomarkers are normalized against a reference marker. Suitable methods and reference markers are described in U.S Pat. No. 10,465,248 and U.S. patent application Ser. No. 16/318,580, the entire contents of each of which are incorporated herein by reference. In some embodiments, the reference marker is selected from β-actin, ZDHHC1, and B3GALT6.


In some embodiments, the reference marker may be ZDHHC1. Exemplary primers and probes for ZDHHC1 are shown in FIG. 16D. In some embodiments, the ZDHHC1 forward primer comprises 5′GTCGGGGTCGATAGTTTACG3′ (SEQ ID NO: 123), the reverse primer comprises 5′ACTCGAACTCACGAAAACG3′ (SEQ ID NO: 124), and the probe comprises 5′CCACGGACGGACGAACGCACG/3C6/3′ (SEQ ID NO: 125).


In some embodiments, the reference marker may be B3GALT6. Exemplary primers and probes for B3GALT6 are shown in FIG. 16E. In some embodiments, the B3GALT6 forward primer comprises 5′GGTTTATTTTGGTTTTTTGAGTTTTCGG3′ (SEQ ID NO:8), the reverse primer comprises 5′TCCAACCTACTATATTTACGCGAA3′ (SEQ ID NO:9), and the probe comprises 5′CCACGGACGGCGGATTTAGGG/3C6/3′ (SEQ ID NO:9).


In some embodiments, the reference marker may be β-actin. Exemplary primers and probes for β-actin are shown in FIG. 16. In some embodiments, the β-actin forward primer is designed for assaying bisulfate-treated β-actin (“BTACT”) DNA, and comprises 5′GTGTTTGTTTTTTTGATTAGGTGTTTAAGA3′ (SEQ ID NO:168), the reverse primer comprises 5′CTTTACACCAACCTCATAACCTTATC3′ (SEQ ID NO:169), and the probe comprises 5′GACGCGGAGATAGTGTTGTGG/3C6/3′ (SEQ ID NO:170).


EXPERIMENTAL EXAMPLES
Example 1
Sample Preparation Methods
Methods for DNA Isolation and QUARTS Assay

The following provides exemplary method for DNA isolation prior to analysis, and an exemplary QuARTS assay, such as may be used in accordance with embodiments of the technology. Application of QuARTS technology to DNA from blood and various tissue samples is described in this example, but the technology is readily applied to other nucleic acid samples, as shown in other examples.


DNA Isolation From Cells and Plasma

For cell lines, genomic DNA may be isolated from cell conditioned media using, for example, the “Maxwell® RSC ccfDNA Plasma Kit (Promega Corp., Madison, Wis.). Following the kit protocol, 1 mL of cell conditioned media (CCM) is used in place of plasma, and processed according to the kit procedure. The elution volume is 100 μL, of which 70 μL are generally used for bisulfite conversion. See also U.S. Patent Appl. Ser. Nos. 62/249,097, filed Oct. 30, 2015; Ser. Nos. 15/335,111 and 15/335,096, both filed Oct. 26, 2016; and International Appl. Ser. No. PCT/US16/58875, filed Oct. 26, 2016, each of which is incorporated herein by reference in its entirety, for all purposes.


An example of a complete process for isolating DNA from a blood sample for use, e.g., in a detection assay, is provided in this example. Optional bisulfite conversion and detection methods are also described.


I. Blood Processing

Whole blood is collected in anticoagulant EDTA or Streck Cell-Free DNA BCT tubes. An exemplary procedure is as follows:

    • 1. Draw 10 mL whole blood into vacutainers tube (anticoagulant EDTA or Streck BCT), collecting the full volume to ensure correct blood to anticoagulant ratio.
    • 2. After collection, gently mix the blood by inverting the tube 8 to 10 times to mix blood and anticoagulant and keep at room temperature until centrifugation, which should happen within 4 hours of the time of blood collection.
    • 3. Centrifuge blood samples in a horizontal rotor (swing-out head) for 10 minutes at 1500 g (±100 g) at room temperature. Do not use brake to stop centrifuge.
    • 4. Carefully aspirate the supernatant (plasma) at room temperature and pool in a centrifuge tube. Make sure not to disrupt the cell layer or transfer any cells.
    • 5. Carefully transfer 4mL aliquots of the supernatant into cryovial tubes.
    • 6. Close the caps tightly and place on ice as soon as each aliquot is made. This process should be completed within 1 hour of centrifugation.
    • 7. Ensure that the cryovials are adequately labeled with the relevant information, including details of additives present in the blood.
    • 8. Specimens can be kept frozen at −20° C. for a maximum of 48 hours before transferring to a −80° C. freezer.


II. Preparation of a Synthetic Process Control DNA

Complementary strands of methylated zebrafish DNA are synthesized having the sequences as shown below using standard DNA synthesis methods such as phosphoramidite addition, incorporating 5-methyl C bases at the positions indicated. The synthetic strands are annealed to create a double-stranded DNA fragment for use as a process control.















SEQ ID



Oligo Name
NO:
Oligo Sequence







Zebrafish RASSF1 me
177
5-TCCAC/iMe-


synthetic Target

dC/GTGGTGCCCACTCTGGACAGGTGGAGCAGAGGGAAGGTGGT


Sense Strand

G/iMe-dC/GCATGGTGGG/iMe-dC/GAG/iMe-dC/G/iMe-




dC/GTG/iMe-dC/GC




CTGGAGGACCC/iMe-dC/GATTGGCTGA/iMe-




dC/GTGTAAACCAGGA/iMe-dC/GA




GGACATGACTTTCAGCCCTGCAGCCAGACACAGCTGAGCTGGTGT




GACCTGTGTGGAGAGTTCATCTGG-3





Zebrafish RASSF1 me
178
5-


synthetic Target

CCAGATGAACTCTCCACACAGGTCACACCAGCTCAGCTGTGTCTGG


Anti-Sense Strand

CTGCAGGGCTGAAAGTCATGTCCT/iMe-




dC/GTCCTGGTTTACA/iMe-dC/GTCAGCCAAT/iMe-




dC/GGGGTCCTCCAGG/iMe-dC/GCA/iMe-dC/G/iMe-




dC/GCT/iMe-dC/GC




CCACCATG/iMe-




dC/GCACCACCTTCCCTCTGCTCCACCTGTCCAGAGTGG




GCACCA/iMe-dC/GGTGGA-3










A. Annealing and Preparation of Concentrated Zebrafish (ZF-RASS F1 180mer) Synthetic Process Control
    • 1. Reconstitute the lyophilized, single stranded oligonucleotides in 10 mM Tris, pH 8.0, 0.1 mM EDTA, at a concentration of 1 μM.
    • 2. Make 10X Annealing Buffer of 500mM NaCl, 200mM Tris-HCl pH 8.0, and 20mM MgCl2.
    • 3. Anneal the synthetic strands:


In a total volume of 100 combine equimolar amounts of each of the single-stranded oligonucleotides in 1× annealing buffer, e.g., as shown in the table below:

















Final Conc.
Volume



Stock
(copies/μl in 1 ml
added


Component
Conc.
final volume)
(μL)







Zebrafish RASSF1 me
1 μM
1.0E+10
16.6


synthetic Target Sense


Strand


Zebrafish RASSF1 me
1 μM
1.0E+10
16.6


synthetic Target Anti-Sense


Strand


Annealing Buffer
10X
NA
10.0


Water
NA
NA
56.8




total vol.
100.0 μL











    • 4. Heat the annealing mixture to 98° C. for 11-15 minutes.

    • 5. Remove the reaction tube from the heat and spin down briefly to collect condensation to bottom of tube.

    • 6. Incubate the reaction tube at room temp for 10 to 25 minutes.

    • 7. Add 0.9 mL fish DNA diluent (20 ng/mL bulk fish DNA in Te (10 mM Tris-HCl pH8.0, 0.1 mM EDTA)) to adjust to the concentration of zebrafish RASSF 1 DNA fragment to 1.0×1010 copies/μl of annealed, double-stranded synthetic zebrafish RASSF 1 DNA in a carrier of genomic fish DNA.

    • 8. Dilute the process control to a desired concentration with 10 mM Tris, pH 8.0, 0.1 mM EDTA, e.g., as described in the table below, and store at either −20° C. or −80° C.




















Target

Total



Initial Concentration
Addition
Te
Volume
Final Concentration







1.00E+10 copies/μL
10 μL
990 μL
1000 μL
1.00E+08 copies/μL


1.00E+08 copies/μL
10 μL
990 μL
1000 μL
1.00E+06 copies/μL










B. Preparation of 100× Stock Process Control (12,000 copies/μL Zebrafish RASSF 1 DNA in 200 ng/μL bulk Fish DNA)
    • 1. Thaw reagents
    • 2. Vortex and spin down thawed reagents
    • 3. Add the following reagents into a 50 mL conical tube















Reagent
Initial Concentration
Final Concentration
Volume to add (mL)




















Stock carrier fish DNA
10
μg/μL
200
ng/μL
0.40


Zebrafish (ZF-RASS F1 180mer)
1.00E+06
copies/μL
1.20E+04
copies/μL
0.24










10 mM Tris, pH 8.0, 0.1 mM EDTA
NA
NA
19.36




Total Volume
20.00











    • 4. Aliquot into labeled 0.5 mL tubes and store @−20° C.


      C. Preparation of 1× Stock of Process Control (120 copies/μL Zebrafish RASSF 1 DNA in 2 ng/μL Fish DNA)

    • 1. Thaw reagents

    • 2. Vortex and spin down thawed reagents

    • 3. Add the following reagents into a 50 mL conical tube:


















Reagent
1 mL
5 mL
10 mL







100x Zebrafish Process Control
 10 μL
 50 μL
 100 μL


10 mM Tris, pH 8.0, 0.1 mM EDTA
990 μL
4950 μL
9900 μL











    • 4. Aliquot 0.3 mL into labeled 0.5 mL tubes and store @−20° C.


      III. DNA extraction from plasma

    • 1. Thaw plasma, prepare reagents, label tubes, and clean and setup biosafety cabinet for extraction

    • 2. Add 300 μL Proteinase K (20 mg/mL) to one 50 mL conical tube for each sample.

    • 3. Add 2 - 4 mL of plasma sample to each 50 mL conical tube (do not vortex).

    • 4. Swirl or pipet to mix and let sit at room temp for 5 min.

    • 5. Add 4 - 6 mL of lysis buffer 1 (LB1) solution to bring the volume up to approximately 8 mL.





LB1 Formulation:

    • 0.1 mL of 120 copies/μL of zebrafish RASSF1 DNA process control, as described above;
    • 0.9 -2.9 mL of 10 mM Tris, pH 8.0, 0.1 mM EDTA (e.g., use 2.9 mL for 2 mL plasma samples)
    • 3 mL of 4.3 M guanidine thiocyanate with 10% IGEPAL (from a stock of 5.3 g of IGEPAL CA-630 combined with 45 mL of 4.8 M guanidine thiocyanate)
    • 6. Invert tubes 3 times.
    • 7. Place tubes on bench top shaker (room temperature) at 500 rpm for 30 minutes at room temperature.
    • 8. Add 200 μL of silica binding beads (16 μg of particles/μL) and mix by swirling.
    • 9. Add 7 mL of lysis buffer 2 (LB2) solution and mix by swirling.


LB2 Formulation:

    • 4 mL 4.3 M guanidine thiocyanate mixed with 10% IGEPAL
    • 3 mL 100% Isopropanol


      (Lysis buffer 2 may be added before, after, or concurrently with the silica binding beads)
    • 10. Invert tubes 3 times.
    • 11. Place tubes on bench top shaker at 500 rpm for 30 minutes at room temperature.
    • 12. Place tubes on capture aspirator and run program with magnetic collection of the beads for 10 minutes, then aspiration. This will collect the beads for 10 minutes then remove all liquid from the tubes.
    • 13. Add 0.9 mL of Wash Solution 1 (3 M guanidine hydrochloride or guanidine thiocyanate, 56.8% EtOH) to resuspend binding beads and mix by swirling.
    • 14. Place tubes on bench top shaker at 400 rpm for 2 minute at room temperature.


      (All subsequent steps can be done on a STARlet automated platform.)
    • 15. Mix by repeated pipetting then transfer containing beads to 96 deep well plate.
    • 16. Place plate on magnetic rack for 10 min.
    • 17. Aspirate supernatant to waste.
    • 18. Add 1 mL of Wash Solution 2 (80% Ethanol, 10 mM Tris pH 8.0).
    • 19. Mix for 3 minutes.
    • 20. Place tubes on magnetic rack for 10 min.
    • 21. Aspirate supernatant to waste.
    • 22. Add 0.5 mL of Wash Solution 2.
    • 23. Mix for 3 minutes.
    • 24. Place tubes on magnetic rack for 5 min.
    • 25. Aspirate supernatant to waste.
    • 26. Add 0.25 mL of Wash Solution 2.
    • 27. Mix for 3 minutes.
    • 28. Place tubes on magnetic rack for 5 min.
    • 29. Aspirate supernatant to waste.
    • 30. Add 0.25 mL of Wash Solution 2.
    • 31. Mix for 3 minutes.
    • 32. Place tubes on magnetic rack for 5 min.
    • 33. Aspirate supernatant to waste.
    • 34. Place plate on heat block at 70° C., 15 minutes, with shaking.
  • 35. Add 125 μL of elution buffer (10 mM Tris-HCl, pH 8.0, 0.1 mM EDTA).
    • 36. Incubate 65° C. for 25 minutes with shaking.
    • 37. Place plate on magnet and let the beads collect and cool for 8 minutes.
    • 38. Transfer eluate to 96-well plate and store at −80° C. The recoverable/transferrable volume is about 100 μL.


IV. Pre-Bisulfite DNA Quantification

To measure DNA in samples using ACTB gene and to assess zebrafish process control recovery, the DNA may be measured prior to further treatment. Setup a QuARTS PCR-flap assay using 10 μL of the extracted DNA using the following protocol:

    • 1. Prepare 10× Oligo Mix containing forward and reverse primers each at 2 μM, the probe and FRET cassettes at 5 μM and deoxynucleoside triphosphates (dNTPs) at 250 μM each. (See below for primer, probe, and FRET sequences)

















SEQ ID
Concentration


Oligo
Sequence (5′-3′)
NO:
(μM)


















ZF RASSF1 UT
CGCATGGTGGGCGAG
179
2


forward





primer








ZF RASSF1 UT
ACACGTCAGCCAATCGGG
180
2


reverse





primer








ZF RASSF1 UT
CCACGGACG GCGCGTGCGTTT/3C6/
181
5


Probe (Arm 3)








Arm 5 FAM
/FAM/TCT/BHQ-1/
182
5


FRET
AGCCGGTTTTCCGGCTGAGACGTCCGTGG/3C6/







ACTB forward
CCATGAGGCTGGTGTAAAG
164
2


primer 3








ACTB Reverse
CTACTGTGCACCTACTTAATACAC
165
2


primer 3








ACTB probe
CGCCGAGGGCGGCCTTGGAG/3C6/
166
5


with Arm 1








Arm 1
/Q670/TCT/BHQ-2/
174
5


QUASAR670
AGCCGGTTTTCCGGCTGAGACCTCGGCG/3C6/




FRET








dNTP mix


2500











    • 2. Prepare a master mix as follows:



















Component
Volume per reaction (μL)



















Water
15.50



10X oligo Mix
3.00



20X Quarts Enzyme Mix*
1.50



total volume
20.0







*20X enzyme mix contains 1 unit/μL GoTaq Hot start polymerase (Promega), 292 ng/μL Cleavase 2.0 flap endonuclease(Hologic).








    • 3. Pipette 10 μL of each sample into a well of a 96 well plate.

    • 4. Add 20 μL of master mix to each well of the plate.

    • 5. Seal plate and centrifuge for 1 minutes at 3000 rpm.

    • 6. Run plates with following reaction conditions on an ABI7500 or Light Cycler 480 real time thermal cycler
















QuARTS Assay Reaction Cycle:
Signal













Ramp Rate
Number
Acqui-


Stage
Temp/Time
(° C. per second)
of Cycles
sition














Pre-incubation
95° C./3 min 
4.4
1
No


Amplification 1
95° C./2 sec 
4.4
5
No



63° C./30 sec
2.2

No



70° C./30 sec
4.4

No


Amplification 2
95° C./20 sec
4.4
40
No



53° C./1 min 
2.2

Yes



70° C./30 sec
4.4

No


Cooling
40° C./30 sec
2.2
1
No









V. Bisulfite Conversion and Purification of DNA





    • 1. Thaw all extracted DNA samples from the DNA extraction from plasma step and spin down DNA.

    • 2. Reagent Preparation:

















Component




Abbreviation
Name
Formulation







BIS SLN
Bisulfite Conversion
56.6% Ammonium Bisulfite



Solution


DES SLN
Desulfonation
70% Isopropyl alcohol, 0.1N NaOH



Solution


BND BDS
Binding Beads
Maxwell RNA Beads (16 mg/mL),




(Promega Corp.)


BND SLN
Binding Solution
7M Guanidine HCl


CNV WSH
Conversion Wash
10 mM Tris-HCl, 80% Ethanol


ELU BUF
Elution Buffer
10 mM Tris, 0.1 mM EDTA, pH 8.0











    • 3. Add 5 μL of 100 ng/μL BSA DNA Carrier Solution to each well in a deep well plate (DWP).

    • 4. Add 80 μL of each sample into the DWP.

    • 5. Add 5 μL of freshly prepared 1.6N NaOH to each well in the DWP(s).

    • 6. Carefully mix by pipetting with pipette set to 30-40 μL to avoid bubbles.

    • 7. Incubate at 42° C. for 20 minutes.

    • 8. Add 120 μL of BIS SLN to each well.

    • 9. Incubate at 66° C. for 75 minutes while mixing during the first 3 minutes.



  • 10. Add 750 μL of BND SLN
    • 11. Pre-mix of silica beads (BND BDS) and add of 50 μL of Silica beads (BND BDS) to the wells of DWP.
    • 12. Mix at 30° C. on heater shaker at 1,200 rpm for 30 minutes.
    • 13. Collect the beads on a plate magnet for 5 minutes followed by aspiration of solutions to waste.
    • 14. Add 1 mL of wash buffer (CNV WSH) then move the plate to a heater shaker and mix at 1,200 rpm for 3 minutes.
    • 15. Collect the beads on a plate magnet for 5 minutes followed by aspiration of solutions to waste.
    • 16. Add 0.25 mL of wash buffer (CNV WSH) then move the plate to the heater shaker and mix at 1,200 rpm for 3 minutes.
    • 17. Collect the beads on a plate magnet followed by aspiration of solutions to waste.
    • 18. Add of 0.2 mL of desulfonation buffer (DES SLN) and mix at 1,200 rpm for 7 minutes at 30° C.
    • 19. Collect the beads for 2 minutes on the magnet followed by aspiration of solutions to waste.
    • 20. Add of 0.25 mL of wash buffer (CNV WSH) then move the plate to the heater shaker and mix at 1,200 rpm for 3 minutes.
    • 21. Collect the beads for 2 minutes on the magnet followed by aspiration of solutions to waste.
    • 22. Add of 0.25 mL of wash buffer (CNV WSH) then move the plate to the heater shaker and mix at 1,200 rpm for 3 minutes.
    • 23. Collect the beads for 2 minutes on the magnet followed by aspiration of solutions to waste.
    • 24. Allow the plate to dry by moving to heater shaker and incubating at 70° C. for 15 minutes while mixing at 1,200 rpm.
    • 25. Add 80 μL of elution buffer (ELU BFR) across all samples in DWP.
    • 26. Incubated at 65° C. for 25 minutes while mixing at 1,200 rpm.
    • 27. Manually Transfer eluate to 96well plate and store at −80° C.
    • 28. The recoverable/transferrable volume is about 65 μL.



VI. QuARTS-X Multiplex Flap Assay for Methylated DNA Detection and Quantification

A. Multiplex PCR (mPCR) Setup:

    • 1. Prepare a 10× primer mix containing forward and reverse primers for each methylated marker of interest to a final concentration of 750 nM each. Use 10 mM Tris-HCl, pH 8, 0.1 mM EDTA as diluent, as described in the examples above.
    • 2. Prepare 10X multiplex PCR buffer containing 100 mM MOPS, pH 7.5, 75 mM MgCl2, 0.08% Tween 20, 0.08% IGEPAL CA-630, 2.5 mM dNTPs.
    • 3. Prepare multiplex PCR master mix as follows:
















Component
Volume per reaction (μL)



















Water
9.62



10X Primer Mix (0.75 μM each)
7.5



mPCR Buffer
7.5



Hot Start GoTaq (5 units/μl)
0.38



total volume
25.0












    • 4. Thaw DNA and spin plate down.

    • 5. Add 25 μL of master mix to a 96 well plate.

    • 6. Transfer 50 μL of each sample to each well.

    • 7. Seal plate with aluminum foil seal (do not use strip caps)

    • 8. Place in heated-lid thermal cycler and proceed to cycle using the following profile, for about 5 to 20 cycles, preferably about 10 to 13 cycles:




















Stage
Temp/Time
Number of Cycles




















Pre-incubation
95° C./5 min 
1



Amplification 1
95° C./30 sec
12




64° C./60 sec



Cooling
4° C./hold 
1












    • 9. After completion of the thermal cycling, perform a 1:10 dilution of amplicon as follows:
      • a) Transfer 180 μL of 10 mM Tris-HCl, pH 8, 0.1 mM EDTA to each well of a deep well plate.
      • b) Add 20 μL of amplified sample to each pre-filled well.
      • c) Mix the diluted samples by repeated pipetting using fresh tips and a 200 μL pipettor (be careful not to generate aerosols).
      • d) Seal the diluted plate with a plastic seal.
      • e) Centrifuge the diluted plate at 1000 rpm for 1 min.
      • f) Seal any remaining multiplex PCR product that has not been diluted with a new aluminum foil seal. Place at −80° C.





B. QuARTS Assay on Multiplex-Amplified DNA:





    • 1. Thaw fish DNA diluent (20 ng/μL) and use to dilute plasmid calibrators (see, e.g., U.S. patent application Ser. No. 15/033,803, which is incorporated herein by reference) needed in the assay. Use the following table as a dilution guide:



















Initial Plasmid
Final plasmid
μL of
μL of
total


Concentration,
Concentration,
plasmid
diluent
volume,


copies per μL
copies per μL
to add
to add
μL



















1.00E+05
1.00E+04
5
45
50


1.00E+04
1.00E+03
5
45
50


1.00E+03
1.00E+02
5
45
50


1.00E+02
1.00E+01
5
45
50











    • 2. Prepare 10× triplex QuARTS oligo mix using the following table for markers A, B, and C (e.g., markers of interest, plus run control and internal controls such as β-actin or B3GALT6 (see, e.g., U.S. Pat. Appln. Ser. No. 62/364,082, incorporated herein by reference).





















Concen-




SEQ ID
tration


Oligo
Sequence (5′-3′)
NO:
(μM)


















Marker A Forward
NA

2


primer








Marker A Reverse
NA

2


primer








Marker A probe-
NA

5


Arm 1








Marker B Forward
NA

2


primer








Marker B Reverse
NA

2


primer








Marker B probe-
NA

5


Arm 5








Marker C Forward
NA

2


primer








Marker C Reverse
NA

2


primer








Marker C probe-
NA

5


Arm 3








Arm 1 HEX FRET
/HEX/TCT/BHQ-1/
171
5



AGCCGGTTTTCCGGCTG





AGACCTCGGCG/3C6/







Arm 5 FAM FRET
/FAM/TCT/BHQ-1/
172
5



AGCCGGTTTTCCGGCTG





AGACGTCCGTGG/3C6/







Arm 3 QUASAR-670
/Q670/TCT/BHQ-2/
173
5


FRET
AGCCGGTTTTCCGGCTGA





GACTCCGCGTC/3C6/







dNTP mix


250









For example, the following might be used to detect bisulfate-treated β-actin, B3GALT6, and zebrafish RASSF1 markers:


















Concen-


Oligo

SEQ ID
tration


Description
Sequence (5′-3′)
NO:
(μM)


















ZF RASSF1 BT
TGCGTATGGTGGGCGAG
160
2


Forward primer








ZF RASSF1 BT
CCTAATTTACACGTCAACCAATCGAA
161
2


Reverse primer








ZF RASSF1 BT
CCACGGACGGCGCGTGCGTTT/3C6/
162
5


probe-Arm 5








B3GALT6 Forward
GGTTTATTTTGGTTTTTTGAGTTTTCGG
8
2


primer








B3GALT6 Reverse
TCCAACCTACTATATTTACGCGAA
9
2


primer








B3GALT6 probe-
CGCCGAGGGCGGATTTAGGG/3C6/
10
5


Arm 1








BTACT Forward
GTGTTTGTTTTTTTGATTAGGTGTTTAAGA
168
2


primer








BTACT Reverse
CTTTACACCAACCTCATAACCTTATC
169
2


primer








BTACT probe-
GACGCGGAGATAGTGTTGTGG/3C6/
170
5


Arm 3








Arm 1 HEX FRET
/HEX/TCT/BHQ-1/
171
5



AGCCGGTTTTCCGGCTGAGACCTCGGCG/3C6/







Arm 5 FAM FRET
/FAM/TCT/BHQ-1/
172
5



AGCCGGTTTTCCGGCTGAGACGTCCGTGG/3C6/







Arm 3 QUASAR-
/Q670/TCT/BHQ-2/
173
5


670 FRET
AGCCGGTTTTCCGGCTGAGACTCCGCGTC/3C6/




dNTP mix


2500











    • 3. Prepare a QuARTS flap assay master mix using the following table:



















Component
Volume per reaction (μL)



















Water
15.5



10X Triplex Oligo Mix
3.0



20X QuARTS Enzyme mix
1.5



total volume
20.0







*20X enzyme mix contains 1 unit/μL GoTaq Hot start polymerase (Promega), 292 ng/μL Cleavase 2.0 flap endonuclease(Hologic).








    • 4. Using a 96 well ABI plates, pipette 20 μL of QuARTS master mix into each well.

    • 5. Add 10 μL of appropriate calibrators or diluted mPCR samples.

    • 6. Seal plate with ABI clear plastic seals.

    • 7. Centrifuge the plate using 3000 rpm for 1 minute.

    • 8. Place plate in ABI thermal cycler programmed to run the following thermal protocol then start the instrument.
















QuARTS Reaction Cycle:
Signal













Ramp Rate
Number of
Acqui-


Stage
Temp/Time
(° C. per second)
Cycles
sition














Pre-incubation
95° C./3 min 
4.4
1
none


Amplification 1
95° C./2 sec 
4.4
5
none



63° C./30 sec
2.2

none



70° C./30 sec
4.4

none


Amplification 2
95° C./20 sec
4.4
40
none



53° C./1 min 
2.2

Yes



70° C./30 sec
4.4

none


Cooling
40° C./30 sec
2.2
1
none









Aliquots of the diluted pre-amplified DNA (e.g., 10 μL) are used in a QuARTS PCR-flap assay, e.g., as described above. See also U.S. Patent Appl. Ser. No. 62/249,097, filed Oct. 30, 2015; Ser. No. 15/335,096, filed Oct. 26, 2016, and PCT/US16/58875, filed Oct. 26, 2016, each of which is incorporated herein by reference in its entirety, for all purposes.


Example 2
Selection and Testing of Methylation Markers for Colorectal Cancer Detection in Plasma

Reduced Representation Bisulfite Sequencing (RRBS) data was obtained on tissues from 19 patients with colon cancer, 19 patients with polyps, 19 healthy patients, and 19 healthy patients buffy coat extracted DNA.


After alignment to an in silico bisulfite-converted version of the human genome sequence, average methylation at each CpG island was computed for each sample type (i.e., tissue or buffy coat) and marker regions were selected based on the following criteria:

    • Regions were selected to be 50 base pairs or longer.
    • For QuARTS flap assay designs, regions were selected to have a minimum of 1 methylated CpG under each of: a) the probe region, b) the forward primer binding region, and c) the reverse primer binding region. For the forward and reverse primers, it is preferred that the methylated CpGs are close to the 3′-ends of the primers, but not at the 3′terminal nucleotide. Exemplary flap endonuclease assay oligonucleotides are shown in FIG. 1.
    • Preferably, buffy coat methylation at any CpG in a region of interest is no more than >0.5%.
    • Preferably, cancer tissue methylation in a region of interest is >10%.
    • For assays designed for tissue analysis, normal tissue methylation in a region of interest is preferably <0.5%.


Based on the criteria above, the markers ANKRD13B; CHST2; CNNM1; DOCK2; DTX1; FERMT3; FLI1; GRIN2D; JAM3; LRRC4; OPLAH; PDGFD; PKIA; PPP2R5C; QKI; SEP9; SFMBT2; SLC12A8; TBX15; TSPYL5; VAV3; ZDHHC1; ZNF304; ZNF568;and ZNF671 were selected and QuARTS flap assays were designed for them, as shown in FIG. 1.


The 25 markers selected from the tissue screening results were triplexed with the assay for bisulfite-converted β-actin and used for testing DNA isolated from plasma samples as described above. CEA protein in the plasma was measured using a Luminex Magplex assay, per manufacturer protocol (Luminex Corp.) DNA from 2 mL of plasma samples (89 cancer and 95 normal) was extracted and eluted in 125 μL. 10 μL aliquots of the extracted DNA were used in a QuARTS assay to detect (3-actin and zebrafish synthetic targets. 80 μL aliquots of the DNA were bisulfite-converted as described in Example 1, and eluted in 70 μL.


A multiplex PCR reaction was performed on 50 μL aliquots of the bisulfite-converted DNA samples, using the forward and reverse primers for the targets shown in FIG. 1, and the markers were detected using QuARTS flap assays, as described in Example 1.


Based on individual marker sensitivities, the following 12 methylation markers were selected for further analysis: VAV3, ZNF671, CHST2, FLI1, JAM3, SFMBT2, PDGFD, DTX1, TSPYL5, ZNF568, GRIN2D, and QKI.


All 12 markers were pre-amplified together using primers as shown for these markers in FIG. 1. The pre-amplified material was analyzed in multiplexed QuARTS assays as described in Example 1, using the primers and probes shown in FIG. 1. The multiplexed assays were grouped as follows:

















CHST2



FLI1



BTACT



VAV3



ZNF671



BTACT



TSPYL5



ZNF568



BTACT



JAM3



SFMBT2



BTACT



PDGFD



DTX1



BTACT



GRIN2D



QKI



BTACT



ZFRASSF1



B3GALT6



BTACT










In addition to the above, the CEA protein was measured for the same samples, as described above. The data and results are shown in FIGS. 3 and 4. The individual marker sensitivities at 90% specificity were as follows:
















Marker
Sensitivity @ 90% specificity









ZNF671
49%



TSPYL5
46%



QKI
41%



JAM3
40%



DTX1
40%



GRIN2D
38%



ZNF568
37%



CEA protein
36%



FLI1
36%



SFMBT2
35%



PDGFD
35%



CHST2
33%



VAV3
31%










At 95% individual cutoff of the individual markers, the following final sensitivity was obtained for using the combined data set.
















Cancer Stage
Negative
Positive
Total # of samples
Sensitivity



















I
14
7
21
33%


II
7
18
25
72%


III
7
17
24
71%


IV
1
18
19
95%


Overall

60
89
67%










The combined specificity of the assay was (88/95=92.6%).


Thus, the combination of these 12 markers plus CEA protein resulted in 67% sensitivity (88 of 95 cancers) for all of the cancer tissues tested, with 92.6% specificity. This panel of methylated DNA markers assayed on tissue achieves extremely high discrimination for all types of colon cancer while remaining negative in normal colon tissue. Assays for this panel of markers can be also be applied to blood or bodily fluid-based testing, and finds applications in, e.g., colon cancer screening.


Multiple Target Sequences Reporting to One Dye

The following experiments related to amplification flap cleavage assays that are configured to have multiple target-specific primary cleavage reactions report to a single FRET cassette, thereby producing fluorescence signal in a single dye channel. Different targets to be detected may be, for example, different markers or genes, different mutations, or different regions of a single marker or gene. Example 3 relates to detecting methylation of multiple different markers associated with cancer, e.g., colorectal cancer, using a single FRET cassette and dye channel, and Example 4 relates to detecting multiple regions within a single marker using a single FRET cassette and dye channel.


Reagents used in the following experiments:













Reagents
Sequence (5′-3′)







VAV3_877 Forward Primer
TCGGAGTCGAGTTTAGCGC



(SEQ ID NO: 108)





VAV3_877 Reverse Primer v2
CGAAATCGAAAAAACAAAAACCGC



(SEQ ID NO: 109)





VAV3_877 Probe (arm 5)
CCACGGACGCGGCGTTCGCGA/3C6/



(SEQ ID NO: 146)





VAV3_11878 forward primer
GAGTCGAGTTTTAGGTTATTCGGT



(SEQ ID NO: 150)





VAV3_11878 reverse primer
CGTCGAACATAAAACCGTAAAAACAA



(SEQ ID NO: 151)





VAV3_11878 probe (arm 5)
CCACGGACGATACGCGCAATA/3C6/



(SEQ ID NO: 152)





SFM8T2_897 Forward Primer v5
GTCGTCGTTCGAGAGGGTA



(SEQ ID NO: 88)





SFMBT2_897 Forward Primer v4
GAACAAAAACGAACGAACGAACA



(SEQ ID NO: 89)





SFMBT2_897 Probe (arm 5) v5
CCACGGACGATCGGTTTCGTT/3C6/



(SEQ ID NO: 90)





SFMBT2_897 probe (arm 1)
CGCCGAGGATCGGTTTCGTT/3C6/



(SEQ ID NO: 141)





SFMBT2_895 forward primer
GCGACGTAGTCGTCGTTGT



(SEQ ID NO: 144)





SFMBT2_895 reverse primer
CCAACGCGAAAAAAACGCG



(SEQ ID NO: 145)





SFMBT2_895 probe (arm 1)
CGCCGAGGGAAAACGCGAAA/3C6/



(SEQ ID NO: 146)





CHST2_7890 Forward Primer
GTATAGCGCGATTTCGTAGCG



(SEQ ID NO: 13)





CHST2_7890 Reverse Primer
AATTACCTACGCTATCCGCCC



(SEQ ID NO: 14)





CHST2_7890 Probe (arm 5)
CCACGGACGCGAACATCCTCC/3C6/



(SEQ ID NO: 15)





CHST2_7890 probe (arm 1)
CGCCGAGGCGAACATCCTCC/3C6/



(SEQ ID NO: 175)





CHST2_7889 forward primer
CGAGTTCGGTAGTTGTACGTAGA



(SEQ ID NO: 138)





CHST2_7889 reverse primer
CGAAATACGAACGCGAAATCTAAAACT



(SEQ ID NO: 139)





CHST2_7889 probe (arm 5)
CCACGGACGTCGTCGATACCG/3C6/



(SEQ ID NO: 140)





CHST2_7889 probe (arm 1)
CGCCGAGG-TCGTCGATACCG/3C6/



(SEQ ID NO: 176)





BTACT_FP65 Forward Primer
GTGTTTGTTTTTTTGATTAGGTGTTTAAGA



SEQ ID NO: 139





BTACT_RP65 Reverse Primer
CTTTACACCAACCTCATAACCTTATC



SEQ ID NO: 140





BTACT Probe A3
GACGCGGAGATAGTGTTGTGG/3C6/



SEQ ID NO: 141





Arm 1 FRET cassette HEX
SEQ ID NO: 170





Arm 5 FRET cassette FAM
SEQ ID NO: 171





Arm 1 FRET cassette QUASAR-670
SEQ ID NO: 174





Arm 3 FRET cassette QUASAR-670
SEQ ID NO: 173







ECOR1 digested pUC57 plasmid (Genscript) containing SFMBT2_897 insert


ECOR1 digested pUC57 plasmid (Genscript) containing CHST2_7890 insert


ECOR1 digested pUC57 plasmid (Genscript) containing VAV3 insert


ECOR1 digested pUC57 plasmid (Genscript) containing BTACT insert


VAV3/BTACT Biplexed plasmids, serially diluted from 1e+04 copies/pi


SFMBT2_897/BTACT Biplexed plasmids, serially diluted from 1e+04 copies/μL


CHST2_7890/BTACT Biplexed plasmids, serially diluted from 1e+04 copies/μL


SFMBT2_897/VAV3/BTACT Biplexed plasmids, 1e+04 copies/μL


CHST2_7890/VAV3/BTACT Biplexed plasmids, 1e+04 copies/μL


CHST2_7890/SFMBT2_897/BTACT Biplexed plasmids, 1e+04 copies/μL


VAV3/CHST2_7890/SFMBT2_897/BTACT Triplexed plasmids, 1e+04 copies/μL


CHST2_7889 + 7890 Calibration curve dilution set (1e4−1e0 cp/ul)


SFMBT2_895 + 897 Calibration curve dilution set (1e4−1e0 cp/ul)


VAV3_877 + 11878 Calibration curve dilution set (1e4−1e0 cp/ul)


VAV3/BTACT 10X Oligo Mix


SFMBT2_897/BTACT 10X Oligo Mix


CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897/CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897 (100 nM F. Primer)/CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897 (50 nM F. Primer)/CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897 (200 nM Probe)/CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897 (250 nM Probe)/CHST2_7890/BTACT 10X Oligo Mix


VAV3/SFMBT2_897 (100 nM Probe)/CHST2_7890/BTACT 10X Oligo Mix


VAV3 (400 nM Primers)/SFM8T2_897 (200 nM Probe)/CHST2_7890/BTACT 10X Oligo Mix


VAV3 (750 nM Probe)/SFM8T2_897 (200 nM Probe)/CHST2_7890/BTACT 10X Oligo Mix


20X Enzyme mix, 1 U/μL Go Taq Hot Start polymerase (Promega), 292 ng/μL Cleavase


2.0 (Hologic)


fDNA Diluent, 20 ng/μL fish DNA in 10 mM Tris, 0.1 mM EDTA


fDNA Diluent, 20 ng/μL fish DNA in 10 mM Tris, 0.1 mM EDTA


Mol. Biol. Grade water


dNTPs, 25 mM (each dNTP)









Example 3
Multiple Markers Reporting to One Dye

As discussed above, in some embodiments it is desirable to have a larger number of markers in a single reaction, using a single FRET cassette and single dye channel. In developing a test for detecting multiple markers reporting to a single FRET cassette and single dye, markers having similar reaction efficiencies (i.e. that produce the same amount of detectable signal per target copy) were selected for combining in a multiplexed reaction reporting to a single dye channel. An advantage of combining detection assays that have the same or similar reaction efficiencies is that any individual calibrator for one of the assays may be used as a calibration standard for any and all of the efficiency-matched detection assays.


Three markers were selected for testing in a multiple marker/one dye system (SFMBT2, VAV3, and CHST2). These target DNAs were mixed in an oligonucleotide mix in which the assay oligonucleotides for all three markers were configured to report to the same FRET cassette and therefore to the same dye (FAM). The three disease-associated markers reporting to the FAM dye were combined in the same reaction with reagents to detect bisulfite-converted β-actin DNA (using a QUASAR 670 FRET cassette) as a control.


When testing on plasmid calibrators was performed, the data showed that using the multiple markers reporting to a single dye is an efficient approach that overcomes the need to run markers in separate wells.


Example 3.1

For QuARTS flap endonuclease assays for multiple different markers to be run in a multiplex reaction reporting to a single FRET cassette, the reaction efficiency for each individual marker was first analyzed so that the reactions could be balanced when combined in a multiplex configuration. Assays were run to determine the assay performance of three selected markers (VAV3, SFMBT2_897 and CHST2_7890) reporting to one dye (FAM), biplexed with bisulfite-converted β-actin (BTACT), which was configured to produce signal reporting to the Quasar 670 channel.


The assays were also configured to determine whether each marker would exhibit similar QuARTS assay performance (slopes/intercepts/Cps) when the three markers are reporting to the same channel (FAM).


An oligonucleotide mix comprising reagents to detect all three methylation markers reporting to a FAM FRET cassette was prepared. The oligonucleotide mix comprised reagents for detecting BTACT reporting to Quasar 670 as a control. This oligonucleotide mix was tested against plasmid targets containing individual plasmids comprising the marker target DNAs and BTACT DNA. Calculations were done to see whether a calibrator curve for one marker could be used to quantitate the other markers accurately. All reactions were done in replicates of 4.


Protocol:

Stock Plasmid dilutions comprising one marker plasmid and one BTACT control plasmid each (see Reagent Table, above) were prepared as follows, in a diluent of 20 ng/μL of fish DNA in 10 mM Tris, 0.1 mM EDTA:















SFMBT2_897/BTACT
Copies in stock
Copies final



plasmid mix
solution, /μL
mixture/μL
μL to add


















SFMBT2_897 Plasmid
1.00E+05
1.00E+04
50


BTACT Plasmid
1.00E+05
1.00E+04
50


Fish DNA Diluent
NA
NA
400


total volume
NA
NA
500






















CHST2_7890/BTACT plasmid mix
Ci, cp/μL
Cf, cp/μL
μL to add


















CHST2_7890 Plasmid
1.00E+05
1.00E+04
50


BTACT Plasmid
1.00E+05
1.00E+04
50


fDNA Diluent
NA
NA
400


total volume
NA
NA
500






















VAV3/BTACT plasmid mix
Ci, cp/μL
Cf, cp/μL
μL to add


















VAV3 Plasmid
1.00E+05
1.00E+04
50


BTACT Plasmid
1.00E+05
1.00E+04
50


fDNA Diluent
NA
NA
400


total volume
NA
NA
500










From the 3 plasmid mixtures prepared above, the following dilutions were prepared:

















Cf, cp/μL
Ci, cp/μL
df
μL Ci to add
μL diluent
total volume







1.00E+05
1.00E+04
10
50
450
500


1.00E+04
1.00E+03
10
50
450
500


1.00E+03
1.00E+02
10
50
450
500


1.00E+02
1.00E+01
10
50
450
500


1.00E+01
1.00E+00
10
50
450
500










10× Oligonucleotide mixes comprising assay oligonucleotides (primers, probes, FRET cassettes) and dNTPs were made as follows:

















Final Reaction
10X oligo Mix


Marker
Reagent
Concentration (μM)
Concentration (μM)


















VAV3
VAV3 Forward Primer
0.2
2


VAV3
VAV3 Reverse Primer v2
0.2
2


VAV3
VAV3 Probe A5
0.5
5


SFMBT2_897
SFMBT2_897 Forward Primer v5
0.2
2


SFMBT2_897
SFMBT2_897 Forward Primer v4
0.2
2


SFMBT2_897
SFMBT2_897 Probe A5 v5
0.5
5


CHST2_7890
CHST2_7890 Forward Primer
0.2
2


CHST2_7890
CHST2_7890 Reverse Primer
0.2
2


CHST2_7890
CHST2_7890 Probe A5
0.5
5



Arm 5 FAM FRET Cassette
0.5
5


BTACT
ACTB_BT_FP65 Forward Primer
0.2
2


BTACT
ACTB_BT_RP65 Reverse Primer
0.2
2


BTACT
ACTB BT Probe A3
0.5
5



Arm 3 QUASAR FRET cassette
0.5
5



dNTPs (each dNTP)
250
2500









QuARTS Flap Endonuclease Assay Reaction Set-Up:

Master mixes for the QuARTS amplification reactions are prepared as follows:












Master Mix Formulation: 96 well plate -










μL vol of stock to
μL vol for38


Reagent
add per reaction
reactions












ddH2O
15.50
589


10X oligo Mix
3.00
114


20X Enzyme Mix
1.50
57


total volume master mix
20.0
760







use 20 ul master mix per well and add 10 ul sample for 96 well


plate = 30 ul final rxn vol









Sample*
10
20.0










Reactions were set up as follows:
    • Pipette 20 μl of master mix into a 96-well QuARTS plate, using a multichannel pipette


Add 10 μl of a sample


Seal plate and centrifuge for 1 min. at 3000 rpm.


Run the plates using the following conditions on the LightCycler480, detecting on FAM, HEX and Quasar 670 channels: 465-510, 533-580, and 618-660 nm













QuARTS Assay Reaction Cycle:
Signal













Ramp Rate
Number
Acqui-


Stage
Temp/Time
(° C. per second)
of Cycles
sition














Pre-incubation
95° C./3 min 
4.4
1
No


Amplification 1
95° C./20 sec
4.4
5
No



63° C./30 sec
2.2

No



70° C./30 sec
4.4

No


Amplification 2
95° C./20 sec
4.4
40
No



53° C./1 min 
2.2

Yes



70° C./30 sec
4.4

No


Cooling
40° C./30 sec
2.2
1
No









Results:

Strand counts using VAV3/BTACT Plasmid Calibrator Standard Curve:












VAV3/BTACT Plasmid Calibrator Standard Curve


















Slope
−3.147684



Intercept
32.08568



Efficiency
107.8%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.36
205,254


20000
18.66
18,432


2000
21.58
2,178


200
24.88
194



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
13.87
612,036


20000
17.17
54,780


2000
19.64
9,021


200
22.12
1,470



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.17
235,836


20000
18.05
28,813


2000
20.39
5,200


200
23.03
752










Strand counts using SFMBT2_897/BTACT Plasmid Calibrator Standard Curve:












SFMBT2_897/BTACT Plasmid Calibrator Standard Curve


















Slope
−2.720157



Intercept
28.53753



Efficiency
133.1%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.36
69,636


20000
18.66
4,282


2000
21.58
362


200
24.88
22



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
13.87
246,543


20000
17.17
15,101


2000
19.64
1,873


200
22.12
229



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.17
81,777


20000
18.05
7,180


2000
20.39
990


200
23.03
106










Strand counts using CHST2_7890//BTACT Plasmid Calibrator Standard Curve:












CHST2_7890/BTACT Plasmid Calibrator Standard Curve


















Slope
−2.59121



Intercept
29.01007



Efficiency
143.2%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.36
184,582


20000
18.66
9,878


2000
21.58
738


200
24.88
39



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
13.87
695,942


20000
17.17
37,096


2000
19.64
4,147


200
22.12
458



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Calculated Average Strands












200000
15.17
218,505


20000
18.05
16,997


2000
20.39
2,123


200
23.03
203









These data show:

    • No cross reactivity or background signal was generated when markers and controls were amplified and detected together;
    • Cp values were similar for CHST2_7890 and VAV3;
    • Cp values for SFMBT2_897 come up at an earlier cycle than CHST2_7890 and VAV3, showing that this is a faster QuARTS assay reaction;
    • SFMBT2_897 calibrator and oligonucleotide mix combination underestimates the count of strands present for VAV3 and CHST2_7890 because of the faster SFMBT2_897 reaction;
    • The CHST2_7890 calibrator provides a VAV3 calculation indicating assay performance equal to the CHST2_7890 assay reaction, but overestimates the amount of SFMBT2_897;
    • The VAV3 calibrator provides a CHST2_7890 calculation indicating assay performance equal to the VAV3 assay reaction, but produces an overestimate of the amount of SFMBT2_897; and
    • To balance the reactions, the QuARTS assay performance in detecting SFMBT2_897 needs to be reduced to match that of SFMBT2_897 and CHST2_7890 targets.


Experiment 3.2

The data above showed that the SFMBT2_897 assay reaction produced higher signal, indicating that the reaction is faster. For the purposes of multiplexing these markers, the SFMBT2_897 assay should be refined to match the efficiency of the slower assays, (i.e., to match the signal output of the VAV3 and CHST2_7890 assays). The following experiment tested whether modifying the concentration of forward primer of the SFMBT2_897 would achieve this.


Protocol:

Assays were run as described in Experiment 3.1, above. 10× oligonucleotide mixes were assembled comprising the components listed above, but having the SFMBT2_897 forward primer in amounts reduced to produce final assay concentrations of 200 nM (as in Experiment 3.1), 100 nM, or 50 nM. The concentration of all other assay primers was 200 nM in the final reaction mixtures, and the Light Cycler protocol was as described in Exp. 3.1.


Results showed that reducing the SFMBT2_897 forward primer concentration seemed to have no effect on the slope or intercept of the signal curve reflecting of PCR efficiency (data not shown). In addition, the Cp value did not change, thus the number of strands calculated for SFMBT2_897 did not match the calculated number of strands of the other marker targets.


Experiment 3.3:

The following experiment tested whether modifying the concentration of the SFMBT2_897 probe would reduce the efficiency of the SFMBT2_897 assay, to match the signal output of the CHST2_7890 and VAV3 amplification reactions.


Assays were run as described above in Experiment 3.1. 10× oligonucleotide mixes were assembled comprising the components listed above, but having the SFMBT2_897 probe oligonucleotide in amounts to produce final assay concentrations of 250 nM or 100 nM, with the CHST2_7890 and VAV3 probes present at 500 nM (as described in Experiment 3.1). The Light Cycler protocol was as described for Experiment 3.1.


Results:

Strand counts using VAV3/BTACT Plasmid Calibrator Standard Curve:












VAV3/BTACT Plasmid Calibrator Standard Curve


















Slope
−3.12175



Intercept
31.55241



Efficiency
109.1%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.95
207,537


20000
18.24
18,377


2000
21.17
2,120


200
24.38
198



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.30
161,043


20000
18.50
15,172


2000
21.20
2,065


200
24.01
260



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.83
226,551


20000
18.08
20,670


2000
21.05
2,318


200
24.30
210










Strand counts using SFMBT2 897/BTACT Plasmid Calibrator Standard Curve:












SFMBT2_897/BTACT Plasmid Calibrator Standard Curve


















Slope
−2.885069564



Intercept
30.72006211



Efficiency
122.1%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.95
291,595


20000
18.24
21,164


2000
21.17
2,045


200
24.38
157



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.30
221,611


20000
18.50
17,200


2000
21.20
1,988


200
24.01
211



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.83
320,609


20000
18.08
24,036


2000
21.05
2,252


200
24.30
168










Strand counts using CHST2 7890/BTACT Plasmid Calibrator Standard Curve:












CHST2_7890/BTACT Plasmid Calibrator Standard Curve


















Slope
−3.136297934



Intercept
31.48713495



Efficiency
108.4%




















VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.95
186,901


20000
18.24
16,737


2000
21.17
1,950


200
24.38
184



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.30
145,201


20000
18.50
13,830


2000
21.20
1,900


200
24.01
242



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.83
203,942


20000
18.08
18,815


2000
21.05
2,131


200
24.30
196









Results:

These data show that adjusting the probe concentrations lower caused the intercept to increase slightly and the PCR % efficiency to increase slightly. The Cp values also increased and therefore the calculation of strand counts gave values similar to the results calculated using the other markers as calibration standards.


The 250 nM SFMBT2_897 probe concentration made the three markers produce similar calculated strand counts, with the SFMBT2_897 strand count values being slightly higher than the other markers. The 50 nM concentration of the probe produced calculated results that slightly underestimated strand counts, but gave some improvement. Therefore, a SFMBT2_897 probe concentration of 200 nM probe was selected for further testing.


Experiment 3.4:

This experiment tested the standard conditions described in Experiment 3.1 (all marker probes used at 500 nM) against the 10× oligonucleotide mix that provides 200 nM SFMBT2_897 probe, with the other probes at 500 nM. This experiment will also determine whether there is an additive effect of having multiple targets in single reaction that all report signal using the same FRET cassette and dye. Single, biplex and triplex combinations of the plasmid targets were used, with all target combinations including the BTACT target as a control.


Plasmid Dilutions for One Marker Plus Control:

For reactions with a single marker plasmid plus a BTACT control plasmid, mixtures were made containing 1.00E+04 copies/μL of each plasmid in a diluent of 20 ng/μL fish DNA in 10 mM Tris, 0.1 mM EDTA. The marker plasmids are described the Reagent Table in Experiment 3.1. The targets in the plasmid mixtures were as follows:

    • SFMBT2_897/BTACT
    • CHST2_7890/BTACT
    • VAV3/BTACT


Plasmid Dilutions for Two Markers Plus Control:

For reactions with two marker plasmids plus a BTACT control plasmid, mixtures were made containing 1.00E+04 copies/μL of each plasmid in a diluent of 20 ng/μL fish DNA in 10 mM Tris, 0.1 mM EDTA. The targets in the plasmid mixtures were as follows:

    • SFMBT2_897/VAV3/BTACT
    • CHST2_7890/VAV3/BTACT
    • CHST2_7890/SFMBT2_897/BTACT


Plasmid Dilutions for Three Markers Plus Control:

For reactions with three marker plasmids plus a BTACT control plasmid, a mixture was made containing 1.00E+04 copies/μL of each plasmid in a diluent of 20 ng/μL fish DNA in 10 mM Tris, 0.1 mM EDTA. The plasmid mixture was as follows:

    • VAV3/CHST2_7890/SFMBT2_897/BTACT


Each of the plasmid mixtures was used to prepare solutions having 1.00E+03 copies/μL and 1.00E+02 copies/μL of each of the plasmids, in fish DNA diluent.


A 10× oligonucleotide mix containing the primers and probes for all 3 markers and for the BTACT control plasmid, and having concentrations of probes to produce 500 nM probe in each QuARTS assay reaction except for the SFMBT2_897 probe, which was provided in an amount to produce a concentration of 200 nM SFMBT2_897 probe in each reaction. The QuARTS assay components were mixed and the assay was performed on a Light Cycler as described in Experiment 3.1.


Results:
Strand Counts Using VAV3/BTACT Plasmid Calibrator Standard Curve:












VAV3/BTACT Plasmid Calibrator Standard Curve


















Slope
−3.164



Intercept
31.977



% Efficiency
107%










Strand Counts for Single Markers, Plus Control Plasmids:












VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.23
195,918


20000
18.39
19,763


2000
21.42
2,179


200
24.77
190



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.08
219,449


20000
18.00
26,151


2000
20.51
4,223


200
23.27
564



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.05
224,915


20000
17.89
28,288


2000
20.41
4,532


200
23.02
680









Strand Counts for Two Markers, Plus Control Plasmids:












VAV3/CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.19
417,946


20000
17.33
42,756


2000
20.09
5,716


200
22.89
743



















Additive Expected Strands


















VAV3/CHST2 Strands
420,833




48,051




6,711




870



















VAV3/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.16
429,911


20000
17.27
44,611


2000
20.08
5,744


200
22.75
823
























VAV3/SFMBT2 Strands
415,367




45,914




6,401




754



















CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.99
485,917


20000
17.17
47,863


2000
19.80
7,068


200
22.34
1,113



















Additive Expected Strands


















CHST2/SFMBT2 Strands
444,364




54,439




8,755




1,244









Strand Counts for Three Markers, Plus Control Plasmids:












VAV3/CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.44
722,434


20000
16.54
76,045


2000
19.21
10,847


200
21.85
1,589



















Additive Expected Strands


















VAV3/CHST2/SFMBT2 Strands
640,282




74,202




10,934




1,434









Strand Counts Using SFMBT2 897/BTACT Plasmid Calibrator Standard Curve:












SFMBT2_897/BTACT Plasmid Calibrator Standard Curve


















Slope
−2.705



Intercept
29.369



% Efficiency
134%









Strand Counts for Single Markers, Plus Control Plasmids:












VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.12
185,009


20000
18.26
12,793


2000
21.28
980


200
24.57
60



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.98
209,356


20000
17.84
18,236


2000
20.38
2,097


200
23.15
200



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.89
225,658


20000
17.72
20,240


2000
20.29
2,275


200
22.86
256









Strand Counts for Two Markers, Plus Control Plasmids:












VAV3/CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.09
446,402


20000
17.22
31,148


2000
19.99
2,926


200
22.72
288



















Additive Expected Strands


















VAV3/CHST2 Strands
410,667




33,033




3,255




315




















VAV3/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.05
460,951


20000
17.17
32,470


2000
19.97
2,983


200
22.60
319



















Additive Expected Strands


















VAV3/SFMBT2 Strands
394,365




31,029




3,077




260




















CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.84
552,761


20000
17.08
34,990


2000
19.65
3,908


200
22.22
439



















Additive Expected Strands


















CHST2/SFMBT2 Strands
435,015




38,476




4,372




455










Strand Counts for Three Markers, Plus Control Plasmids:












VAV3/CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.31
863,327


20000
16.40
62,334


2000
19.12
6,171


200
21.69
692



















Additive Expected Strands


















VAV3/CHST2/SFMBT2 Strands
620,024




51,269




5,353




515










Strand Counts Using CHST2 7890/BTACT Plasmid Calibrator Standard Curve:












CHST2_7890/BTACT Plasmid Calibrator Standard Curve


















Slope
−2.644



Intercept
29.02



% Efficiency
139%










Strand Counts for Single Markers, Plus Control Plasmids:












VAV3/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.14
177,035


20000
18.28
11,490


2000
21.30
828


200
24.60
47



















SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
15.01
199,391


20000
17.88
16,382


2000
20.41
1,808


200
23.17
162



















CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.93
213,922


20000
17.75
18,236


2000
20.31
1,966


200
22.89
209









Strand Counts for Two Markers, Plus Control Plasmids:












VAV3/CHST2_7890/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.11
436,308


20000
17.24
28,620


2000
20.02
2,542


200
22.75
235



















Additive Expected Strands


















VAV3/CHST2 Strands
390,956




29,726




2,794




255




















VAV3/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
14.07
448,748


20000
17.18
29,908


2000
19.99
2,596


200
22.62
262



















Additive Expected Strands


















VAV3/SFMBT2 Strands
376,425




27,872




2,637




209




















CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.87
535,611


20000
17.10
32,329


2000
19.68
3,405


200
22.24
365



















Additive Expected Strands


















CHST2/SFMBT2 Strands
413,312




34,618




3,774




371










Strand Counts for Three Markers, Plus Control Plasmids:












VAV3/CHST2_7890/SFMBT2_897/BTACT Plasmid Calibrator









Calibrator Strands/Rxn
Average Cp
Average Strands












200000
13.34
853,557


20000
16.42
57,973


2000
19.13
5,479


200
21.72
578



















Additive Expected Strands


















VAV3/CHST2/SFMBT2 Strands
590,347




46,108




4,602




418










These data confirm the results shown in Experiment 3.2, showing that adjustment of the SFMBT2_897 probe concentration down to 200 nM aligns the efficiency of this assay reaction with the efficiencies of the reactions for detecting VAV3 and CHST2_7890. They also show that when multiple targets in a reaction report signal to the same FRET cassette and dye channel, the result shows an additive effect on the amount of fluorescence signal produced in the reaction. Surprisingly, no increase in background or cross reactivity is observed. The data further show that, when the VAV3 dilution series is used as the calibration standard, the strand counts of SFMBT2_897 and CHST2_7890 DNAs calculated from the data at the low end of the curve are overestimates of the amounts actually added to these reactions. The VAV3 amplification curves are more variable at the lower end of the standard curve, causing overestimates of strand counts for the other markers.


Experiment 3.5:

In this experiment, the probe and primer concentrations of the VAV3 marker were adjusted to reduce overestimation of low-level targets when the VAV3 calibrator curve is used for as the reference curve for calculating DNA concentrations.


For the VAV3 calibration curve, a dilution series having the VAV3 plasmid combined with the BTACT plasmid was as described in Experiment 3.4. Plasmid dilutions having all three markers plus the BTACT control were used.


10× oligonucleotide mixes containing the primers and probes for all 3 markers and for the BTACT control plasmid were made, having primers and probes provided to produce the concentrations shown below:

    • 1. VAV3 (400 nM Primers)/SFMBT2_897 (200 nM Probe)ICHST2_7890/BTACT
    • 2. VAV3 (750 nM Probe)/SFMBT2_897 (200 nM Probe)ICHST2_7890/BTACT
    • 3. VAV3/SFMBT2_897 (200 nM Probe)ICHST2_7890/BTACT


With the exception of the variations in primer and probe concentrations indicated above, the final reaction concentrations of all other primers was 200nM each primer, and of all other probes was 500 nM for each probe. The QuARTS assay reactions were mixed and the assay was performed on a Light Cycler as described in Experiment 3.1.


Both condition modifications improve the slope of the low calibrator in the VAV3 assay, but these conditions do produce signal that is the same as the single marker oligonucleotide mix. The data show that the single marker mix does not have the issue of over-estimation of strand counts at the low end of the standard curve. Based on these data, 400 nM each VAV3 primer with 500 nM probe was selected for investigation of testing the assay on clinical samples.


Experiment 3.6

This experiment tests the multiple marker/1 dye sample configuration on human clinical plasma samples. Plasma samples were previously tested using the standard one marker:one dye method, as described in Example 2. The same samples were re-tested using an oligonucleotide mix that has VAV3, SFMBT2_897 and CHST2_7890 reporting to one fluorescent channel (FAM).


In Example 2, DNA was prepared from a series of plasma samples and the target DNAs were amplified QuARTS assays. Amplicon material produced in Example 2 from the samples 105-120 (see FIG. 3) was diluted 1:10, and tested using the 3-target/1control oligonucleotide mix described above in Experiment 3.5.


The single marker/BTACT plasmid calibrator dilutions were as described in Experiment 3.1. A 10× oligonucleotide mix comprising primers and probes for all three markers and for the BTACT control DNA, and configured to produce reactions having the 400 nM each VAV3 primer and 200 nM SFMBT2_897 probe, and having all other primers at 200 nM and all other probes at 500 nM, as described in Experiment 3.5, was used. The QuARTS assays were mixed and the assay was performed on a Light Cycler as described in Experiment 3.1. Each reaction was run in duplicate.


The counts of target strands for each of the samples were separately calculated using each of the three different marker calibration curves. The resulting strand count values were similar, regardless of which standard curve was used. In addition, the strand counts for each of the samples using the single-dye configuration were close to the combined strand counts for this set of markers measured in Example 2 using separate FRET cassettes and dye channels. Further, samples that had zero strands detected, i.e., that produced no signal in the Example 2 experiment, stayed at zero when using the multiple markers reporting to one dye configuration, showing that background signal is not increased when the multiplexed reactions report to a FRET cassette/single dye channel.


These results show that using multiple different target sites, e.g., multiple different marker genes, reporting to one FRET cassette and the same dye can increase the sensitivity of detection, and also show that multiplex combinations need not be limited by the number of available dye channels for signal detection. In addition, the use of this approach is not limited to having a single dye per reaction well. For example, an assay could be configured having three (or more) markers reporting to a first dye (e.g., FAM) and three (or more) markers reporting to a second dye (e.g., HEX), doubling the number of markers that may be tested in a single reaction, on a single preparation of nucleic acid sample. Additional dye channels may be used for additional sets of markers and/or for one or more internal control targets.


Example 4
Multiple Regions of a Marker Reporting to One Dye

For three methylation markers VAV3 (877), SFMBT2 (897), and CHST2 (7890), that showed low to zero strand counts in normal plasma using the methods described herein above, additional QuARTS assay oligonucleotide sets targeting other regions within each of the markers were designed and tested, to see whether detecting additional regions of the markers in the same reaction and reporting to the same dye channel would increase the signal-to-noise ratio for each marker, thus increasing the sensitivity of the assay, e.g., in detection of cancer.


For each of these markers, two different regions determined by RRBS to have differential methylation between cancer tissue and normal tissue were identified. Those regions are:

    • VAV3 region 877: chr1: 108507618-108507675
    • VAV3 region 11878: chr1: 108507406-108507499
    • SFMBT2 region 895: chr10: 7452337-7452406
    • SFMBT2 region 897: chr10: 7452865-7452922
    • CHST2 region 7890: chr3:142838847-142839000
    • CHST2 region 7889: chr3: 142838300-142838388


Experiment 4.1

The CHST2 regions (7889 and 7890) reporting to the HEX dye were tested both individually and in a combined reaction to evaluate any synergy between the two regions when combined. A calibrator plasmid containing CHST2 insert was diluted as described in Experiment 3.1 to produce a dilution series of 1E4 to 1E0 copies per μL. For individual detection of region 7889, assay reactions contained the forward and reverse primers and the arm 1 probe for CHST2_7889, the Arm 1 HEX FRET cassette, and the primers and the arm 3 probe for the BTACT control, along with the Arm 3 Quasar 670 FRET cassette. For individual detection of region 7890, assay reactions contained the forward and reverse primers and the arm 1 probe for CHST2_7890, the Arm 1 HEX FRET cassette, and the primers and arm 3 probe for the BTACT control, along with the Arm 3 Quasar 670 FRET cassette. The combined reaction contained the complete set of arm 1 probes and primers for both CHST2_7889 and 7890, along with the oligonucleotides for detection of BTACT and the same two FRET cassettes.


10× oligonucleotide mixes contained the primers and probes at concentrations to produce 500 nM of each probe and 200 nM of each primer in each QuARTS assay reaction. The QuARTS assay components were mixed and the assay was performed on a Light Cycler as described in Experiment 3.1.


It was found that in the combined reaction, having these two regions report to the same dye using a single FRET cassette did not result in any increase in signal. The CHST2_7889 amplification was substantially more efficient and appeared to dominate the resulting signal, suggesting that the different reactions should be modified to have more similar efficiencies, as discussed above in Example 3.


Experiment 4.2 Experiments were conducted to determine what probe concentration should be used for each pair of regions in each marker {CHST2 (7889 and 7890), SFMBT2 (895 and 897) and VAV3 (877 and 11878)} to balance the reaction kinetics between the different regions. 10× oligonucleotide mixes were made to provide the following mixtures of assay oligonucleotides at the indicated final concentrations:












CHST2_7890A (1xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















CHST2_7890
CHST2_7890 FP
0.2



CHST2_7890
CHST2_7890 RP
0.2



CHST2_7890
Probe A5 CHST2_7890
0.5




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















CHST2_7889A (1xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















CHST2_7889
F Primer CHST2_7889
0.2



CHST2_7889
R Primer CHST2_7889
0.2



CHST2_7889
Probe A5 CHST2_7889
0.5




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















CHST2_7890A (3xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















CHST2_7890
CHST2_7890 FP
0.2




CHST2_7890 RP
0.2




Probe A5 CHST2_7890
1.5




A5 FAM FRET
0.5



ACTB
ACTB_BT_FP65
0.2




ACTB_BT_RP65
0.2




ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















CHST2_7890A (2xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















CHST2_7890
CHST2_7890 FP
0.2




CHST2_7890 RP
0.2




Probe A5 CHST2_7890
1




A5 FAM FRET
0.5



ACTB
ACTB_BT_FP65
0.2




ACTB_BT_RP65
0.2




ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















CHST2_7889A (0.5xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















CHST2_7889
F Primer CHST2_7889
0.2




R Primer CHST2_7889
0.2




Probe A5 CHST2_7889
0.25




A5 FAM FRET
0.5



ACTB
ACTB_BT_FP65
0.2




ACTB_BT_RP65
0.2




ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















SFMBT2_895A (1xProbe)











Final 1X


Marker
Oligo
Conditions (μM)












SFMBT2_895v2
FP SFMBT2_895_v2
0.2



RP SFMBT2_895_v2
0.2



Prb A1 SFMBT2_895 v2
0.5



A1 HEX FRET
0.5


ACTB
ACTB_BT_FP65
0.2



ACTB_BT_RP65
0.2



ACTB BT Pb A3
0.5



A3 Quasar670 FRET
0.5



dNTPs
250



water
NA



















SFMBT2_897/BTACT


SFMBT2_897A (1xProbe)











Final 1X


Marker
Oligo
Conditions (μM)












SFMBT2_897
F Primer SFMBT2_897v5
0.2



R Primer SFMBT2_897v4
0.2



Probe A1 SFMBT2_897v5
0.5



A1 HEX FRET
0.5


ACTB
ACTB_BT_FP65
0.2



ACTB_BT_RP65
0.2



ACTB BT Pb A3
0.5



A3 Quasar670 FRET
0.5



dNTPs
250



water
NA



















SFMBT2_897A (0.5xProbe)











Final 1X


Marker
Oligo
Conditions (μM)












SFMBT2_897
F Primer SFMBT2_897v5
0.2



R Primer SFMBT2_897v4
0.2



Probe A1 SFMBT2_897v5
0.25



A1 HEX FRET
0.5


ACTB
ACTB_BT_FP65
0.2



ACTB_BT_RP65
0.2



ACTB BT Pb A3
0.5



A3 Quasar670 FRET
0.5



dNTPs
250



water
NA



















SFMBT2_895A (2xProbe)











Final 1X


Marker
Oligo
Conditions (μM)












SFMBT2_895v2
FP SFMBT2_895_v2
0.2



RP SFMBT2_895_v2
0.2



Prb A1 SFMBT2_895 v2
1



A1 HEX FRET
0.5


ACTB
ACTB_BT_FP65
0.2



ACTB_BT_RP65
0.2



ACTB BT Pb A3
0.5



A3 Quasar670 FRET
0.5



dNTPs
250



water
NA



















SFMBT2_897A (0.25xProbe)











Final 1X


Marker
Oligo
Conditions (μM)












SFMBT2_897
F Primer SFMBT2_897v5
0.2



R Primer SFMBT2_897v4
0.2



Probe A1 SFMBT2_897v5
0.125



A1 HEX FRET
0.5


ACTB
ACTB_BT_FP65
0.2



ACTB_BT_RP65
0.2



ACTB BT Pb A3
0.5



A3 Quasar670 FRET
0.5



dNTPs
250



water
NA



















VAV3 877A (1xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_877
F Primer VAV3
0.2



VAV3_877
R Primer VAV3 ver 2
0.2



VAV3_877
Probe A5 VAV3
0.5




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















VAV3_878A (1xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_11878
F Primer VAV3_11878
0.2



VAV3_11878
R Primer VAV3_11878
0.2



VAV3_11878
Probe A5 VAV3_11878
0.5




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















VAV3_877A(1.5xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_877
F Primer VAV3
0.2



VAV3_877
R Primer VAV3 ver 2
0.2



VAV3_877
Probe A5 VAV3
0.75




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















VAV3_877A(2xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_877
F Primer VAV3
0.2



VAV3_877
R Primer VAV3 ver 2
0.2



VAV3_877
Probe A5 VAV3
1




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















VAV3_878(0.75xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_11878
F Primer VAV3_11878
0.2



VAV3_11878
R Primer VAV3_11878
0.2



VAV3_11878
Probe A5 VAV3_11878
0.375




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA




















VAV3_878(0.5xProbe)













Final 1X



Marker
Oligo
Conditions (μM)















VAV3_11878
F Primer VAV3_11878
0.2



VAV3_11878
R Primer VAV3_11878
0.2



VAV3_11878
Probe A5 VAV3_11878
0.25




A5 FAM FRET
0.5



BTACT
ACTB_BT_FP65
0.2



BTACT
ACTB_BT_RP65
0.2



BTACT
ACTB BT Pb A3
0.5




A3 Quasar670 FRET
0.5




dNTPs
250




water
NA










The QuARTS assay components were mixed and the assays were performed on a Light Cycler as described in Experiment 3.1 The average Cp values achieved under the different reaction conditions are as follows:















Average Cp Values












Plasmid
CHST2_7890
CHST2_7890
CHST2_7890
CHST2_7889
CHST2_7889


Calibrator
1XProbe
2XProbe
3XProbe
1XProbe
0.5XProbe


Concentration
Conc.
Conc.
Conc.
Conc.
Conc.















200,000
15.4
14.8
14.2
13.9
14.7


20,000
18.6
18.0
17.4
17.1
18.1


2,000
22.1
21.4
21.0
20.6
21.2


200
25.2
24.9
24.2
24.0
24.7


20
28.7
27.8
27.0
27.2
28.1






















Average Cp Values












Plasmid
SFMBT2_895
SFMBT2_895
SFMBT2_897
SFMBT2_897
SFMBT2_897


Calibrator
1XProbe
2XProbe
1XProbe
0.25XProbe
0.5XProbe


Concentration
Conc.
Conc.
Conc.
Conc.
Conc.















200,000
16.5
15.2
14.5
16.7
16.0


20,000
20.1
19.1
18.0
20.1
19.3


2,000
23.4
22.6
21.3
23.3
22.5


200
27.1
26.1
24.4
26.5
25.8


20
30.2
29.4
27.4
30.6
29.3






















Average CP Values













Plasmid
VAV3_877
VAV3_877
VAV3_877
VAV3_11878
VAV3_11878
VAV3_11878


Calibrator
1XProbe
1.5XProbe
2XProbe
1XProbe
0.75XProbe
0.5XProbe


Concentration
Conc.
Conc.
Conc.
Conc.
Conc.
Conc.
















200,000
15.0
14.5
14.2
13.4
13.8
14.3


20,000
18.2
17.9
17.6
16.9
17.0
17.8


2,000
21.6
21.3
21.0
20.3
20.3
21.1


200
25.2
24.4
24.2
23.4
23.8
24.2


20
27.9
28.1
27.3
26.7
27.5
27.5









These data show that by varying the probe concentrations, it is possible to adjust the Cp values for the individual assays to the point where each of the five points of the calibration curve are within <1 Cp for each of the two regions for each marker. For the markers tested, use of the following probe concentrations in the QuARTS assay reactions produced balanced reaction efficiencies for the sets of target regions:


















Marker

[Probe]-A5-FAM
[Probe]-A1-HEX




















SFMBT2_895

 0.5 uM



SFMBT2_897

0.125 uM












CHST2_889
0.25
uM




CHST2_7890
1
uM




VAV3_877
1
uM




VAV3_11878
0.25
uM











Experiment 4.3

New triplex reactions (see Example 2 for original triplex reaction configurations) were designed to use the multiple region/one dye assay configurations in multiplexed reactions. “Pool 17” below lists a set of 6 markers co-amplified with a β-actin control, then analyzed in triplex QuARTS assays in the groupings shown below. Pool 17+MR-OD is adapted to include the multiple regions/one dye assay configurations for the SFMBT2, VAV3, and CHST2 markers. The JAM3, ZNF671, and ZNF568 assay designs were as shown in FIG. 1 and FIG. 2. The 3- or 4-letter abbreviations for each grouping in the pools are the first letter of each gene name, with A indicating the β-actin control.


















Pool 17

Pool 17 + MR-OD





















JSA
JAM3
JSSA
JAM3




SFMBT2_897

SFMBT2_897




BTACT

SFMBT2_895



VZA
VAV3_877

BTACT




ZNF671
VVZA
VAV3_877




BTACT

VAV3_11878



CZA1
CHST2_7890

ZNF671




ZNF568

BTACT




BTACT
CCZA1
CHST2_7890






CHST2_7889






ZNF568






BTACT










The new triplex formulations were tested on a plasmid calibration dilution series comprising the Pool 17 multiplex, comprising all target regions in the groups listed above, in a series of dilutions providing 2e5 to 2e1 strands of each target per assay reaction. The final concentrations of the probes for the SFMBT2, VAV3, and CHST2 MR-OD were as described in the results of Experiment 4.2. The probes for JAM3, ZNF671, and ZNF568 markers and for the BTACT control were 1 μM. All FRET cassettes were at 500 nM in the final reactions mixtures. The QuARTS assay components were mixed and the assays were performed on a Light Cycler as described in Experiment 3.1 The triplex containing VAV3-877 plus VAV3-11878 performed as expected, giving approximately 2 to 3-fold increase in strand count over the count of target added to the reaction, while the targets having only one region targeted . However, the triplexes containing CHST2-7889_CHST2-7890 and SFMBT2-895_SFMBT2-897 did not show the expected additive signal. Further experiments were conducted using different concentrations of the probes for CHST2-7889_CHST2-7890 and SFMBT2-895_SFMBT2-897, to test them in the multiplex QuARTS assays grouped as shown above. Within the triplex format, it was possible to modify the probe concentration of CHST2_7889 and CHST2_7890 to achieve the expected MR_OD results (i.e., results having the expected additive values of the individual reactions) based on a plasmid calibration curve. However, SFMBT2_895 and SFMBT2_897 assay, while improved using the modified probe concentrations, when used in the triplex format the assay still produced signal below the expected 200% level expected for detection of two regions. Nonetheless, the following modified probe concentrations were selected for testing the triplex assays on plasma samples.












Revised Final Probe Concentrations for MR-OD Reactions











Marker_region
[Probe]-Arm5-FAM
[Probe]-Arm 1-HEX







SFMBT2_895

  1 uM



SFMBT2_897

0.25 uM



CHST2_7889
0.5 uM




CHST2_7890
1.5 uM




VAV3_877
  1 uM




VAV3_11878
0.25 uM 











Experiment 4.4

This experiment examined the effect of combining multiplex pre-amplification and triplex QuARTS assay detection using the multiple regions-one dye assay designs to test human plasma samples from both normal and cancer patients. The experiment compared detection of 13 methylation markers (plus Process Control, ZF_RASSF1) of Pool 17 to detection using the Pool 17+MR_OD configuration on 63 normal plasma samples and 12 colon cancer plasma samples. The markers of Pool 17 were co-amplified together in a pre-amplification, then the pre-amplified DNA was detected in the list of grouped reactions listed below, and as described in detail in Example 1.


















Pool 17

Pool 17 + MR-OD





















JSA
JAM3
JSSA
JAM3




SFMBT2

SFMBT2_897




BTACT

SFMBT2_895



PDA
PDGFD

BTACT




DTX1
PDA
PDGFD




BTACT

DTX1



GQA
GRIN2D

BTACT




QKI
GQA
GRIN2D




BTACT

QKI



VZA
VAV3

BTACT




ZNF671
VVZA
VAV3_877




BTACT

VAV3_11878



CZA1
CHST2

ZNF671




ZNF568

BTACT




BTACT
CCZA1
CHST2_7890



AFA
ANKRD13B

CHST2_7889




FER1L4

ZNF568




BTACT

BTACT



CZA2
CNNM1
AFA
ANKRD13B




ZFRASSF1

FER1L4




BTACT

BTACT





CZA2
CNNM1






ZFRASSF1






BTACT










The triplex names comprise the first letter of each included marker, plus ‘A’ for the β-actin control. Double letters in the triplex names (e.g., “JSSA”) in the right-hand column indicate single markers tested at two different regions.


DNA was isolated from plasma samples as described in Example 1. Bisulfite conversion, multiplex pre-amplification, and QuARTS assay on multiplex-amplified DNA were conducted as described in Example 1. Prior to bisulfite conversion, aliquots of the isolated DNA were saved for testing KRAS 38A and 35C mutations on unconverted DNA. The amplification primers and detection probes used for each marker were as shown in FIGS. 1 and 2.


A logistic linear regression fit using strands-per-reaction for VAV3, SFMBT2, CHST2, and ZNF671 showed a considerable advantage when QuARTS is used in combination with MR_OD (multiple regions_one dye) as compared to the standard QuARTS assay configuration, as shown below. In these analysis, the marker ZNF671 was a major contributor to the detection results, and was included in the logistic fit for both QuARTS only and QuARTS+MR_OD. As noted above, KRAS 38A and 35C mutations the unconverted DNA were also tested.


The following sensitivity and specificity was obtained for using the multiplex pre-amplification with the standard triplex assays:












Multiplex with standard QuARTS assay




















Prediction














Stage
N Tested
Cancer
Normal
Sensitivity







I
4
2
2
50%



II
3
2
1
67%



III
3
2
1
67%



IV
2
2
0
100% 
















Prediction
% Sensitivity/











Pathology
N Tested
Cancer
Normal
Specificity





Cancer
12
8
4
 67%


Normal
62
0
62
100%









When the multiple region/one dye configuration was used, the sensitivity and specificity were as follows:












Multiplex with QuARTS assay using Multiple


Regions_one Dye (MR_OD)












Prediction














Stage
N Tested
Cancer
Normal
Sensitivity

















I
4
4
0
100%



II
3
3
0
100%



III
3
2
1
 67%



IV
2
2
0
100%


























Prediction
% Sensitivity/











Pathology
N Tested
Cancer
Normal
Specificity














Cancer
12
11
1
92%


Normal
62
6
56
90%









Although the sample size is small, the use of this multiple region-to-one dye (FRET cassette) configuration shows substantial improvement in sensitivity, but may result in some loss of specificity.


It should be noted that, while this example detected DNA isolated from plasma samples, this panel of markers and use of the multiplex QuARTS assay modified as described above can be applied to stool or other blood or bodily fluid-based testing, and find application in, e.g., colon cancer and other cancer screening.


not limited to, patents, patent applications, articles, books, treatises, and internet web pages are expressly incorporated by reference in their entirety for any purpose. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which the various embodiments described herein belongs. When definitions of terms in incorporated references appear to differ from the definitions provided in the present teachings, the definition provided in the present teachings shall control.


Various modifications and variations of the described compositions, methods, and uses of the technology will be apparent to those skilled in the art without departing from the scope and spirit of the technology as described. Although the technology has been described in connection with specific exemplary embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in pharmacology, biochemistry, medical science, or related fields are intended to be within the scope of the following claims.

Claims
  • 1. An ingestible cell sampling device comprising: i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule.;ii) a molded cap comprising a cap interior surface and a cap exterior surface; andiii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge.
  • 2. The ingestible cell sampling device of claim 1, further comprising an unswallowable handle attached to the string.
  • 3. The ingestible cell sampling device of claim 2, wherein the string has a second end, wherein the unswallowable handle is attached to the string at the second end.
  • 4. The ingestible cell sampling device of claim 1, wherein the dissolvable capsule comprises one or more openings, wherein a portion of the abrasive sponge is exposed to the external environment at the one or more openings.
  • 5. The ingestible cell sampling device of claim 1, wherein the dissolvable capsule comprises a first end and a second end, wherein: a) the first end is closed and the second end is closed; orb) the first end is closed and the second end is open.
  • 6. The ingestible cell sampling device of claim 5, wherein the cap interior surface is in contact with the exterior surface of the capsule at the first closed end, and the cap exterior surface is in contact with the external environment.
  • 7. The ingestible cell sampling device of claim1, wherein the cap interior surface is in contact with the abrasive sponge.
  • 8. The ingestible cell sampling device of claim 7, wherein the cap exterior surface is in contact with an internal surface of the capsule at the first closed end and/or with the external environment.
  • 9. The ingestible cell sampling device of claim 7, wherein the cap interior surface is attached to the abrasive sponge by an adhesive.
  • 10. The ingestible cell sampling device of claim 1, wherein the cap interior surface is attached to the abrasive sponge.
  • 11. The ingestible cell sampling device of claim 1, wherein the string is attached to the molded cap by a knot and/or an adhesive.
  • 12. A system or kit for obtaining a cell sample from a subject, comprising an ingestible cell sampling device of claim 1; and further comprising one or more of: i) a container to receive an abrasive sponge comprising collected cells;ii) a cell preservative reagent, preferably a buffer reagent;iii) a microscope slide;iv) an assay plate;v) a local anesthetic treatment, preferably a local anaesthetic spray;vi) a component of a drinkable solution; preferably a pre-mixed drinkable solution; andvii) a lubricant, preferably a lubricant gel or liquid.
  • 13. A method of obtaining a cell sample from a subject, comprising: a) orally administering an abrasive sponge housed within a dissolvable capsule of a ingestible cell sampling device of to the subject, wherein the ingestible cell sampling device comprises: i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule.;ii) a molded cap comprising a cap interior surface and a cap exterior surface; andiii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge, andb) withdrawing from the subject the abrasive sponge, wherein the abrasive sponge collects a cell sample from the subject during the withdrawing.
  • 14. A method of characterizing an esophageal cell sample from a subject, comprising: a) preparing DNA from the esophageal cell sample from the subject;b) treating the DNA with bisulfite to produce bisulfite-treated DNA; andc) amplifying the bisulfite-treated DNA to determine an amount of at least one methylated biomarker gene selected from the group of methylation biomarker genes consisting of ANKRD13B, BMP3, CD1D, CDKN2A , CHST2, CNNM1, DIO3, DOCK2, DTX1, ELMO1, FER1L4, FERMT3, FLI1, GRIN2D, HUNK, JAM3, LRRC4, NDRG4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, ZNF671, and ZNF682;d) assaying the bisulfite-treated DNA from the esophageal cell sample for an amount of a reference DNA; ande) comparing the amount of the at least one methylated biomarker gene to the amount of the reference DNA to determine a methylation state for the at least one methylation biomarker gene in the esophageal cell sample.
  • 15. The method of claim 14, comprising obtaining the esophageal cell sample from the subject by a method comprising: a) orally administering an abrasive sponge housed within a dissolvable capsule of a ingestible cell sampling device of to the subject, wherein the ingestible cell sampling device comprises: i) an abrasive sponge housed within a dissolvable capsule, the dissolvable capsule comprising an exterior surface exposed to an external environment, wherein the abrasive sponge is retained in a compressed state by the dissolvable capsule.;ii) a molded cap comprising a cap interior surface and a cap exterior surface; andiii) a string having a first end attached to the molded cap, wherein the string passes through a portion of the abrasive sponge andb) withdrawing from the subject the abrasive sponge, wherein the abrasive sponge collects an esophageal cell sample from the subject during the withdrawing.
  • 16. The method of claim 14, wherein determining the methylation state for the at least one methylation biomarker gene in the esophageal cell sample comprises determining the methylation state of no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, or 33 methylation biomarker genes selected from the group consisting of ANKRD13B, BMP3, CD1D, CDKN2A , CHST2, CNNM1, DIO3, DOCK2, DTX1, ELMO1, FER1L4, FERMT3, FLI1, GRIN2D, HUNK, JAM3, LRRC4, NDRG4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, ZNF671, and ZNF682.
  • 17. The method of claim 16, wherein the at least one methylated biomarker gene is selected from the group of methylation biomarker genes consisting of: ANKRD13B, CHST2, CNNM1, DOCK2, DTX1, FER1L4, FERMT3, FLI1, GRIN2D, JAM3, LRRC4, OPLAH, PDGFD, PKIA, PPP2R5C, QKI, SEP9, SFMBT2, SLC12A8, TBX15, TSPYL5, VAV3, ZNF304, ZNF568, and ZNF671.
  • 18. The method of claim 16, wherein the at least one methylated biomarker gene is selected from the group of methylation biomarker genes consisting of: BMP3, NDRG4, VAV3, SFMBT2, DIO3, HUNK, ELMO1, CD1D, CDKN2A, and OPLAH.
  • 19. The method of claim 14, wherein the reference DNA is methylated.
  • 20. The method of claim 14, wherein determining the amount of the at least one methylated biomarker gene comprises using one or more methods selected from the group consisting of methylation-specific PCR, quantitative methylation-specific PCR, methylation-sensitive DNA restriction enzyme analysis, quantitative bisulfite pyrosequencing, flap endonuclease assay, PCR-flap assay, and bisulfite genomic sequencing PCR.
Parent Case Info

The present application claims priority to U.S. Provisional Application Ser. No. 63/011,684, filed Apr. 17, 2020, which is incorporated herein by reference.

Provisional Applications (1)
Number Date Country
63011684 Apr 2020 US