None.
The present invention relates to systems and methods for treating cancer with cold atmospheric plasma.
Among women worldwide, breast cancer is the most frequently diagnosed cancer and the most common cause of cancer death. Bray, F., et al., Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin, 2018. 68(6): p. 394-424. The major breast cancer molecular subtypes are based on estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) expression. Howlader, N., et al., Differences in Breast Cancer Survival by Molecular Subtypes in the United States. Cancer Epidemiology, Biomarkers & Prevention, 2018. 27(6): p. 619-626. With a total of eight combinations of ER, PR and HER2 expression (see Bauer, K., C. Parise, and V. Caggiano, Use of ER/PR/HER2 subtypes in conjunction with the 2007 St Gallen Consensus Statement for early breast cancer. BMC Cancer, 2010. 10), breast cancer is acknowledged as a highly complex disease. Molecular profiling, however, can provide information on disease prognosis and therapeutic approach. Kittaneh, M., A. J. Montero, and S. Gluck, Molecular profiling for breast cancer: a comprehensive review. Biomark Cancer, 2013. 5: p. 61-70; Duffy, M. J., et al., Clinical use of biomarkers in breast cancer: Updated guidelines from the European Group on Tumor Markers (EGTM). Eur J Cancer, 2017. 75: p. 284-298 N Approximately 75% of breast cancers are ER-positive (ER+) while 55-65% are PR-positive (PR+). See Anderson, W. F., et al., Estrogen receptor breast cancer phenotypes in the Surveillance, Epidemiology, and End Results database. Breast Cancer Research and Treatment, 2002. 76(1): p. 27-36; Colditz, G. A., et al., Risk factors for breast cancer according to estrogen and progesterone receptor status. J Natl Cancer Inst, 2004. 96(3): p. 218-28; and Nadji, M., et al., Immunohistochemistry of estrogen and progesterone receptors reconsidered: experience with 5,993 breast cancers. Am J Clin Pathol, 2005. 123(1): p. 21-7.
Survival rates of patients are highest with ER+/PR+ tumors, intermediate with either ER+/PR− or ER−/PR+ tumors, and lowest with ER−/PR− tumors. Alanko, A., et al., Significance of Estrogen and Progesterone Receptors, Disease-Free Interval, and Site of First Metastasis on Survival of Breast Cancer Patients. Cancer, 1985. 56(7): p. 1696-700
Several studies have reported changes in hormone receptor status between primary and metastatic breast cancer with discordance rates estimated to be 20% for ER and 40% for PR (both of which are higher than HER2 discordance rate). See, Curtit, E., et al., Discordances in estrogen receptor status, progesterone receptor status, and HER2 status between primary breast cancer and metastasis. Oncologist, 2013. 18(6): p. 667-74; RJ, B., et al., Changes in Estrogen Receptor, Progesterone Receptor and Her-2/neu Status with Time: Discordance Rates Between Primary and Metastatic Breast Cancer. Anticancer Research, 2009. 29(5): p. 1557-62; Sighoko, D., et al., Discordance in hormone receptor status among primary, metastatic, and second primary breast cancers: biological difference or misclassification? Oncologist, 2014. 19(6): p. 592-601; and Liedtke, C., et al., Prognostic impact of discordance between triple-receptor measurements in primary and recurrent breast cancer. Ann Oncol, 2009. 20(12): p. 1953-8. Patients with discordant receptor status have lower rates of survival than patients with consistent receptor status possibly due ineffective therapeutic interventions compared to patients with consistent receptor status. Tamoxifen, a selective estrogen-receptor modulator, reduces risk of disease recurrence by 47% after 5 years and mortality by 26% after 10 years in ER+ patients (Riggs, B. L. and L. C. Hartmann, Selective estrogen-receptor modulators—mechanisms of action and application to clinical practice. N Engl J Med, 2003. 348(7): p. 618-29) but increases the risk for thromboembolic events significantly (Pritchard, K. I., et al., Increased Thromboembolic Complications with Concurrent Tamoxifen and Chemotherapy in a Randomized Trial of Adjuvant Therapy for Women with Breast Cancer. Journal of Clinical Oncology, 1996. 14(10): p. 2731-7) and absence of ER expression is associated with de novo resistance to tamoxifen (Johnston, S. R. D., et al., Changes in Estrogen Receptor, Progesterone Receptor, and pS2 Expression in Tamoxifen-resistant Human Breast Cancer. Cancer Research, 1995. 55(15): p. 3331-8). In comparison, patients treated with letrozole, an aromatase inhibitor, had a lower chance of relapse over a 5-year period but reported increased incidences of adverse events. Coates, A. S., et al., Five years of letrozole compared with tamoxifen as initial adjuvant therapy for postmenopausal women with endocrine-responsive early breast cancer: update of study BIG 1-98. J Clin Oncol, 2007. 25(5): p. 486-92.
HER2 amplification (HER2+) occurs in approximately 25-30% of primary human breast cancers and is the most significant prognostic factor compared to other factors such as ER, PR, tumor size, and age. See, Slamon, D. J., et al., Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. Science, 1987. 235(4785): p. 177-82; and Slamon, D. J., et al., Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer. Science, 1989. 244(4905): p. 707-12. HER2, in addition to other human epidermal growth factor (hEGF) receptors, is involved in a complex network of pathways that are responsible for signaling normal cellular processes such as cell growth, migration, differentiation, and death. Yarden, Y. and M. X. Sliwkowski, Untangling the ErbB signaling network. Nature Reviews Molecular Cell Biology, 2001. 2(2): p. pages 127-137. An overexpression of HER2, therefore, promotes aggressive tumor behavior which is characterized by significantly decreased rates of disease-free and overall survival. Trastuzumab (Herceptin), a humanized monoclonal antibody developed to target and inhibit the function of HER2 (Molina, M. A., et al., Trastuzumab (Herceptin), a Humanized Anti-HER2 Receptor Monoclonal Antibody, Inhibits Basal and Activated HER2 Ectodomain Cleavage in Breast Cancer Cells. Cancer Research, 2001. 61(12): p. 4744-9), is a generally well-tolerated monotherapy for metastatic HER2-positive breast cancers. See, Vogel, C. L., et al., Efficacy and Safety of Trastuzumab as a Single Agent in First-Line Treatment of HER2-Overexpressing Metastatic Breast Cancer. Journal of Clinical Oncology, 2002. 20(3): p. 719-726; and Baselga, J., et al., Phase II study of efficacy, safety, and pharmacokinetics of trastuzumab monotherapy administered on a 3-weekly schedule. J Clin Oncol, 2005. 23(10): p. 2162-71. Randomized trials have reported adjuvant and neoadjuvant trastuzumab improved chance of overall survival in HER2+ breast cancer patients than those who received only chemotherapy. See, Smith, I., et al., 2-year follow-up of trastuzumab after adjuvant chemotherapy in HER2 positive breast cancer: a randomised controlled trial. The Lancet, 2007. 369(9555): p. 29-36; Gianni, L., et al., Neoadjuvant and adjuvant trastuzumab in patients with HER2-positive locally advanced breast cancer (NOAH): follow-up of a randomised controlled superiority trial with a parallel HER2-negative cohort. The Lancet Oncology, 2014. 15(6): p. 640-647; and Slamon, D. J., et al., Use of Chemotherapy plus a Monoclonal Antibody against HER2 for Metastatic Breast Cancer That Overexpresses HER2. New England Journal of Medicine, 2001. 344(11): p. 783-792. However, risk of cardiac dysfunction was significantly raised in combination with anthracycline and cyclophosphamide according to Slamon et. al. Moreover, a 25-35% chance of central nervous system metastasis 6-12 months after the start of trastuzumab-based therapies due to the inability of trastuzumab to cross the blood-brain barrier have been reported. See, Clayton, A., et al., Incidence of cerebral metastases in patients treated with trastuzumab for metastatic breast cancer. British Journal of Cancer, 2004. 91: p. 639-643; Bendell, J. C., et al., Central nervous system metastases in women who receive trastuzumab-based therapy for metastatic breast carcinoma. Cancer, 2003. 97(12): p. 2972-7; and Gori, S., et al., Central nervous system metastases in HER-2 positive metastatic breast cancer patients treated with trastuzumab: incidence, survival, and risk factors. Oncologist, 2007. 12(7): p. 766-73. FDA-approved dual anti-HER2 regimen, pertuzumab in combination with trastuzumab and docetaxel, significantly improved progression-free survival but with >30% of patients exhibiting side effects such as diarrhea, neutropenia, nausea, fatigue, and peripheral neuropathy. Blumenthal, G. M., et al., First FDA approval of dual anti-HER2 regimen: pertuzumab in combination with trastuzumab and docetaxel for HER2 positive metastatic breast cancer. Clin Cancer Res, 2013. 19(18): p. 4911-6.
The overexpression of ER, PR, and HER2 is classified as triple positive breast cancer (TPBC). Vici, P., et al., Triple positive breast cancer: a distinct subtype? Cancer Treat Rev, 2015. 41(2): p. 69-76 It is estimated that 10% of all breast cancer tumors are ER+/PR+/HER2+. Howlader, N., et al., US incidence of breast cancer subtypes defined by joint hormone receptor and HER2 status. J Natl Cancer Inst, 2014. 106(5).; Onitilo, A. A., et al., Breast cancer subtypes based on ER/PR and Her2 expression: comparison of clinicopathologic features and survival. Clin Med Res, 2009. 7(1-2): p. 4-13. Since HR and HER2 receptors are expressed, TPBCs can be treated with hormonal and HER2− targeted therapies. Overall and disease-free survival in ER+/PR+/HER2+ patients significantly improves in response to a combination of endocrine therapy, trastuzumab, and chemotherapy. Hayashi, N., et al., Adding hormonal therapy to chemotherapy and trastuzumab improves prognosis in patients with hormone receptor-positive and human epidermal growth factor receptor 2-positive primary breast cancer. Breast Cancer Res Treat, 2013. 137(2): p. 523-31. However, endocrine therapy resistance has been linked to crosstalk between ER and HER2 signaling pathways. See, AlFakeeh, A. and C. Brezden-Masley, Overcoming endocrine resistance in hormone receptor-positive breast cancer. Curr Oncol, 2018. 25(Suppl 1): p. S18-S27; Osborne, C. K. and R. Schiff, Mechanisms of endocrine resistance in breast cancer. Annu Rev Med, 2011. 62: p. 233-47; and Giuliano, M., M. V. Trivedi, and R. Schiff, Bidirectional Crosstalk between the Estrogen Receptor and Human Epidermal Growth Factor Receptor 2 Signaling Pathways in Breast Cancer: Molecular Basis and Clinical Implications. Breast Care (Basel), 2013. 8(4): p. 256-62.
Triple negative breast cancer (TNBC) characterized by the lack of expression of ER, PR, and HER2 accounts for approximately 10 to 20% of all breast cancers. Trivers, K. F., et al., The epidemiology of triple-negative breast cancer, including race. Cancer Causes Control, 2009. 20(7): p. 1071-82; Rakha, E. A., et al., Prognostic markers in triple-negative breast cancer. Cancer, 2007. 109(1): p. 25-32; Qiu, J., et al., Comparison of Clinicopathological Features and Prognosis in Triple-Negative and Non-Triple Negative Breast Cancer. J Cancer, 2016. 7(2): p. 167-73; Dent, R., et al., Triple-negative breast cancer: clinical features and patterns of recurrence. Clin Cancer Res, 2007. 13(15 Pt 1): p. 4429-34. Compared to all other breast cancer phenotypes, despite adjuvant chemotherapy TNBC has a significantly higher the rate of recurrence and risk of metastatic spread to the lungs, liver, and brain. Dent, R., et al., Triple-negative breast cancer: clinical features and patterns of recurrence. Clin Cancer Res, 2007. 13(15 Pt 1): p. 4429-34. While neoadjuvant chemotherapy has achieved a higher rate of pathologic complete response in TNBC patients than in non-TNBC patients, TNBC patients with residual disease have higher recurrence and death rates in the first 3 years than non-TNBC patients with residual disease. Liedtke, C., et al., Response to Neoadjuvant Therapy and Long-Term Survival in Patients with Triple-Negative Breast Cancer. Journal of Clinical Oncology, 2008. 26(8): p. 1275-1281. TNBC patients do not respond to endocrine therapy or HER2-targeted therapies, such as trastuzumab. Liedtke, C., et al., Response to neoadjuvant therapy and long-term survival in patients with triple-negative breast cancer. Journal of Clinical Oncology, 2008. 26(8): p. 1275-81; Wahba, H. A. and H. A. El-Hadaad, Current approaches in treatment of triple-negative breast cancer. Cancer Biol Med, 2015. 12(2): p. 106-16. Recently there has been a growing interest in TRAIL (TNF (tumor necrosis factor)-related apoptosis-inducing ligand) which activates Death Receptors (DR) 4 and 5 to induce apoptosis. Oakman, C., G. Viale, and A. Di Leo, Management of triple negative breast cancer. Breast, 2010. 19(5): p. 312-21. Potential TRAIL-targeting therapies have demonstrated the ability to induce apoptosis in TNBC cell lines with a mesenchymal phenotype (Rahman, M., et al., TRAIL induces apoptosis in triple-negative breast cancer cells with a mesenchymal phenotype. Breast Cancer Res Treat, 2009. 113(2): p. 217-30) and suppresses tumor growth and metastasis in mice models. Jyotsana, N., et al., Minimal dosing of leukocyte targeting TRAIL decreases triple-negative breast cancer metastasis following tumor resection. Science Advances, 2019. 5(7); Greer, Y. E., et al., MEDI3039, a novel highly potent tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptor 2 agonist, causes regression of orthotopic tumors and inhibits outgrowth of metastatic triple-negative breast cancer. Breast Cancer Res, 2019. 21(1): p. 27. Another target of interest for TNBC are cyclin dependent kinases (CDK) or cell cycle regulators. Lynce, F., A. N. Shajahan-Haq, and S. M. Swain, CDK4/6 inhibitors in breast cancer therapy: Current practice and future opportunities. Pharmacol Ther, 2018. 191: p. 65-73. Several FDA-approved CDK4/6 inhibitors (palbociclib, ribociclib and abemaciclib) have been shown to improve survivability, although accompanied by neutropenia, fatigue, nausea and diarrhea. Up until recently, TNBC treatment options were limited to surgery, chemotherapy, and radiotherapy, however, the development of therapies non-dependent on receptor status is promising for TNBC patients.
Cold atmospheric plasma (CAP) technology utilizes ionized gas for various applications such as wound healing, HIV treatment, and cancer treatment. Keidar, M., et al., Cold atmospheric plasma in cancer therapy. Physics of Plasmas, 2013. 20(5); Arpitha, P., Cold Atmospheric Plasma as an Alternative Therapy for Cancer Treatment. Cell & Developmental Biology, 2015. 04(02). A Cold Plasma Conversion System, composed of the Cold Plasma Scalpel with a Cold Plasma Conversion Unit, is an electrosurgical system that produces CAP for the treatment of surgical margins upon tumor resection (U.S. Pat. No. 9,999,462). One of the advantages of cold atmospheric plasma systems is that the CAP temperature remains between 26-30° C. during the duration of the treatment (Cheng, X., et al., Treatment of Triple-Negative Breast Cancer Cells with the Canady Cold Plasma Conversion System: Preliminary Results. Plasma, 2018. 1(1): p. 218-228) and does not cause any thermal or physical damage to normal tissue (Ly, L., et al., A New Cold Plasma Jet: Performance Evaluation of Cold Plasma, Hybrid Plasma and Argon Plasma Coagulation. Plasma, 2018. 1(1): p. 189-200). Our previous studies have demonstrated the ability of the system to significantly reduce the viability of various malignant solid tumor cell lines (including pancreatic adenocarcinoma, renal adenocarcinoma, esophageal adenocarcinoma, colorectal carcinoma, and ovarian adenocarcinoma) by 80-99% 48 hours post-CAP treatment. Rowe, W., et al., The Canady Helios Cold Plasma Scalpel Significantly Decreases Viability in Malignant Solid Tumor Cells in a Dose Dependent Manner. Plasma, 2018. 1(1): p. 177-188. For breast adenocarcinoma, TNBC in particular, an 80% reduction of cell viability was achieved 48 hours after treatment with the CCPCS.
Several different systems and methods for performing Cold Atmospheric Plasma (CAP) treatment have been disclosed. For example, U.S. Pat. No. 10,213,614 discloses a two-electrode system for CAP treatment. U.S. Pat. Nos. 9,999,462 and 10,023,858 each disclose a converter unit for using a traditional electrosurgical system with a single electrode CAP accessory to perform CAP treatment. WO 2018191265A1 disclosed an integrated electrosurgical generator and gas control module for performing CAP.
In a preferred embodiment, the present invention is a novel treatment approach for cancer using Cold Atmospheric Plasma. More specifically, the present invention is a for reduction of cell viability by cold plasma conversion system treatment on breast cancers based on molecular profiling.
In a preferred embodiment, the present invention is a method for treatment of breast cancer. The method comprises performing a molecular analysis of target breast cancer cells, identifying markers associated with the target breast cancer cells based on the performed molecular analysis, selecting on a graphical user interface of a cold atmospheric plasma generator the identified markers associated with the target breast cancer cells, selecting with a processor in the cold atmospheric plasma generator preferred cold atmospheric plasma settings associated with the identified markers in a database stored in a storage in the cold atmospheric plasma generator, and applying cold atmospheric plasma with the cold atmospheric plasma generator at the selected cold atmospheric pressure settings to the target breast cancer cells. The selected CAP settings may include time and power. The method may further comprise treating the target breast cancer cells with one of chemotherapy and radiation therapy to reduce resistance of the target cancer cells' resistance to cold atmospheric plasma treatment.
Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a preferable embodiments and implementations. The present invention is also capable of other and different embodiments and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description or may be learned by practice of the invention.
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description and the accompanying drawings, in which:
Breast cancer is a heterogenous disease which can be classified into subtypes by the presence or absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 receptor (HER2). Cold atmospheric plasma (CAP) has been shown to be a potential treatment for cancer. With the present invention, a 92-99% reduction of viability by CAP treatment was achieved across all tested breast cancer cell lines (p 0.05). Increasing treatment duration and power significantly reduced breast cancer cell viability (** f(2,2)≤0.0176, *** f(5,14)≤0.0033). The present invention utilizes the discovery that CAP sensitivity in breast cancer cells is based on receptor status. Cells with identical receptor status show the least difference in CAP sensitivity (p≤0.05), the difference being 33% between the two ER+/PR+/HER2− cell lines (p≤0.05) and 22-44% between the three TNBC cell lines (p≤0.05). HER2-negative status, irrespective of ER/PR status, also showed ≤50% difference in CAP sensitivity (p≤0.05). Moreover, demonstration of ER−/PR−/HER2+ CAP susceptibility and ER+/PR+/HER2+ CAP resistance suggests that ER/PR status is a significant factor in determining CAP sensitivity in HER2-positive cells. These findings on CAP sensitivity provide the present invention with the ability to optimize CAP treatment to better overcome CAP resistance and thus prevent tumor recurrence.
A method for treating breast cancer in accordance with a preferred embodiment of the present invention is shown in
A preferred embodiment of a CAP enabled generator is described with reference to the drawings. A gas-enhanced electrosurgical generator 200 in accordance with a preferred embodiment of the present invention is shown in
A generator housing front panel 210 is connected to the housing 202. On the face front panel 210 there is a touchscreen display 212 and there may be one or a plurality of connectors 214 for connecting various accessories to the generator 200. For a cold atmospheric plasma generator such as is shown in
As shown in
As shown in
Another embodiment, shown in
In the above-disclosed embodiment, a cold atmospheric plasma below 35° C. is produced. When applied to the tissue surrounding the surgical area, the cold atmospheric plasma induces metabolic suppression in only the tumor cells and enhances the response to the drugs that are injected into the patient.
The cold plasma applicator 500 may be in a form such as is disclosed in U.S. Pat. No. 10,405,913 and shown in
Through experiments such as are described below, most-effective CAP setting can be determined with respect to various genetic markers in cancer cells. Using results of such experiments, a database of most-effective settings and corresponding molecular makers can be generated and stored in the memory 232 of the CAP generator 200 or may be stored elsewhere and accessed by the CPU 230 in the generator. The graphical user interface on the touchscreen display 212 then may be used to select or enter particular genetic markers to cause the CAP generator to automatically select the preferred settings for performing CAP on a particular line of target cancer cells. The database, of course, may include more complicated sets of data such as a type of chemotherapy or radiation therapy to be performed in conjunction with the application of CAP, for example, such that the CAP generator may select the appropriate CAP setting based upon the specific markers found in the molecular analysis of the cancer cells in combination with a type of other therapy being performed.
The present inventors evaluated the efficacy of the cold atmospheric plasma on various breast cancer cell lines based on ER, PR, and HER2 status. The human breast cancer cell lines that were studied include MCF-7, T-47D, SK-BR-3, BT-474, MDA-MB-231, Hs578T, and HCC1806. Receptor status of these cell lines are shown in Error! Reference source not found.
All experiments were performed at Jerome Canady Research Institute for Advanced Biological and Technological Sciences, Takoma Park, Md., USA, using a Cold Plasma Conversion System. The electrosurgical device consisted of the USMI SS-601 MCa high-frequency electrosurgical generator (USMI, Takoma Park, Md., USA) integrated with a USMI Canady Cold Plasma Conversion Unit and connected to a Canady Helios Cold Plasma™ Scalpel. The conversion unit has three connectors: a gas connector (to a helium tank), and electrical connector (to the generator), and an electro-gas connector (to the scalpel). The conversion unit also features a high voltage transformer that up-converts voltage up to 4 kV, down-converts frequency to less than 300 kHz, and down-converts power less than 40 W. Additional details and schematics on plasma generation are described in Cheng, X., et al., Treatment of Triple-Negative Breast Cancer Cells with the Canady Cold Plasma Conversion System: Preliminary Results. Plasma, 2018. 1(1): p. 218-228.
The helium flow rate was set to a constant 3 L/min and the power was set to 80, 100 and 120 P. The plasma scalpel tip was placed 1.5 cm above the surface of the cell media and remained unmoved for the duration of the treatment. The CAP treatment was performed in a laminar flow tissue culture hood, Purifier Logic+ Class II, Type A2 Biosafety Cabinet (Labconco, Kansas City, Mo., USA) at room temperature.
Human breast cancer cell lines T-47D, SK-BR-3, and BT-474, were purchased from ATCC (Manassas, Va., USA). MCF-7, MDA-MB-231, Hs578T, and HCC1806 were generously donated by Professor Kanaan's laboratory at Howard University. All cell lines except SK-BR-3 were cultured in Roswell Park Memorial Institute (RPMI) 1640 Medium supplemented with 10% fetal bovine serum (Sigma-Aldrich, St. Louis, Mo., USA) and 1% Pen Strep (Thermo Fisher Scientific, Waltham, Mass., USA) in a 37° C. and 5% CO2 humidified incubator (Thermo Fisher Scientific, Waltham, Mass., USA). The exceptions for culture conditions include T-47D, which was additionally supplemented with 0.5 mg/mL insulin. SK-BR-3 was cultured in McCoy's 5A Medium. When cells reached approximately 80% confluence, cells were seeded at a concentration of 105 cells/well into 12-well plates (USA Scientific, Ocala, Fla., USA) with a 1 mL media volume per well for cell viability assays.
Thiazolyl blue tetrazolium bromide (MTT) assay was performed on the cells 48 h after plasma treatment following the manufacturer's protocol with all MTT assay reagents purchased from Sigma-Aldrich (St. Louis, Mo., USA). The absorbance of the dissolved compound was measured by BioTek Synergy HTX (Winooski, Vt., USA) microplate reader at 570 nm.
All viability assays were repeated 3 times with 2 replicates each. Data was plotted by Microsoft Excel 2016 as the mean±standard error of the mean. A student t-test or a one-way analysis of variance (ANOVA) was used to check statistical significance where applicable. The differences were considered statistically significant for * p≤0.05. A one-way multivariate analysis of variance (MANOVA) followed by a Post-Hoc test was used to check statistical significance where applicable. The differences were considered statistically significant for **f≤0.0176 and for *** f≤0.0033.
Various operational parameters of the cold atmospheric plasma system were tested to determine the CAP dosage necessary to significantly reduce viability of each breast cancer cell line. A flow rate of 3 L/min was selected for all experimental conditions with power settings of 80, 100, and 120 P. Treatment duration ranged from 1-6 min to reduce viability by at least 90%. MTT assays were performed to assess viability 48 hours post-CAP treatment.
The viabilities of both the ER+/PR+/HER2− cell lines, MCF-7 and T-47D were reduced to approximately 1% (p≤0.0001) and 5% (p≤0.0001), respectively, after given the highest CAP dose of 120 P for 6 min (
To evaluate whether receptor status was also significant factor in the reduction of viability by CAP treatment, the statistical significance of viability data was considered between cell lines across all treatment condition, displayed in
The purpose of these experiments was to determine the sensitivity of breast cancer cell lines to CAP treatment based on the receptor status. Identical receptor status showed the least difference in CAP sensitivity within the two ER+/PR+/HER2− cell lines (33%) and the three TNBC cell lines (22-44%) (p≤0.05) (
This data suggests that ER/PR status is most important determining factor in CAP susceptibility for HER2+ breast cancer cells. Testing additional TPBC and ER−/PR−/HER2+ cell lines in future studies could further supplement our findings on CAP sensitivity. Nonetheless, the present data suggests molecular profile should be considered when determining the optimal CAP dosage for the treatment of breast cancer, especially in HER2+ breast cancer. Potentially, adjuvant and neoadjuvant trastuzumab or hormonal therapy alongside CAP treatment could improve the chance of overall survival in HER2+ breast cancer patients. The molecular pathway that determines the susceptibility of HER2+ cells to CAP treatment warrants further investigation. An insight on CAP mechanism will give us a better understanding on how to optimize CAP treatment to better overcome CAP resistance.
The data indicates that differential regulation of apoptotic genes is a major contributor to CAP selectivity. The importance of apoptotic malfunction in the TNBC prognosis is well documented in several studies. Nedeljkovic, M. and A. Damjanovic, Mechanisms of Chemotherapy Resistance in Triple-Negative Breast Cancer-How We Can Rise to the Challenge. Cells, 2019. 8(9). Poor prognosis in TNBC is attributed to pro-survival factors, such as B-cell lymphoma 2 (Bcl-2) (Inao, T., et al., Bcl-2 inhibition sensitizes triple-negative human breast cancer cells to doxorubicin. Oncotarget, 2018. 9(39): p. 25545-25556) and myeloid cell leukemia 1 (Mcl-1). Additionally, TRAIL receptors also contribute to apoptosis dysregulation, however targeted therapies against TRAIL and several DRs have failed to improve patient outcomes. Lemke, J., et al., Getting TRAIL back on track for cancer therapy. Cell Death Differ, 2014. 21(9): p. 1350-64. By identifying and targeting molecular markers responsible for CAP resistance, a greater reduction of viability by smaller CAP dosages can be achieved.
Different cell media may influence CAP sensitivity. In this experiment, SK-BR-3 was the only cell line to be cultured in McCoy 5A media as opposed to RPMI 1640 (all of which was in accordance with ATCC recommendations). A study done jointly with The George Washington University, investigated the interaction between CAP-generated effective species and amino acids present in the media. It was concluded that cysteine and tryptophan consumed the most CAP-generated effective species, thus weakening the anti-tumor ability of CAP on cells. See, Yan, D., et al., Principles of using Cold Atmospheric Plasma Stimulated Media for Cancer Treatment. Sci Rep, 2015. 5: p. 18339. However, when glioblastoma and breast cancer cells were cultured in the same type of media, glioblastoma cells consumed CAP-generated effective species at a faster rate than breast cancer cells, suggesting distinct expression of extracellular proteins dependent on cell line. Gene profiling reveals that oxidative stress-related genes cause preferential uptake of reactive oxygen and nitrogen species by CAP susceptible cells.
Promising cancer therapeutic potential of the cold atmospheric plasma system has been demonstrated. Additionally, CAP treatment alongside chemotherapy can further improve breast cancer management. Furthermore, the present findings on CAP sensitivity will be the foundation in the development of customized CAP-based therapy regiments for various breast cancer subtypes.
There is a present demand for a therapy that effectively treats all breast cancer subtypes regardless of receptor status since effectiveness of current endocrine and HER2-targeted therapies are dependent on receptor status. Liedtke, C., et al., Response to neoadjuvant therapy and long-term survival in patients with triple-negative breast cancer. Journal of Clinical Oncology, 2008. 26(8): p. 1275-81; Wahba, H. A. and H. A. El-Hadaad, Current approaches in treatment of triple-negative breast cancer. Cancer Biol Med, 2015. 12(2): p. 106-16. To this end, the cold atmospheric plasma system can be offered as a solution after demonstrating its ability to reduce breast cancer viability by 92-99% (p≤0.05) regardless of receptor status. The present experiments revealed that molecular profiling when selecting appropriate CAP dosages is beneficial especially in HER2-positive breast cancers in which ER/PR status is a significant factor in determining CAP sensitivity.
The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.
The present application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 62/953,767 filed by the present inventors on Dec. 26, 2019. The aforementioned provisional patent application is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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62953767 | Dec 2019 | US |