Manjili, M. | bioRxiv Science

bioRxiv2020

Combining Two Classes of Epigenetic Modifiers and Their Effect on Prostate Cancer Cells

The main objective of this experiment was to determine and study the effects of combining two epigenetic modifiers, 5-azacyticidine (5-AzaC) and SB939, on a RM-1 murine prostate cancer cell model. The effectiveness of this combination on prostate cancer cells has not been previously studied. The study was implemented on ex vivo cell models to gain a better understanding of the true effects of the combination therapy on prostate cancer cells. Two variations of the combination therapy were tested in this study, each with different concentrations of SB939 (100nm and 200nm). To determine the effectivity of the combination therapy on prostate cancer cells, three factors were measured: cell proliferation, cancer testis antigen (CTA) expression, and apoptosis rate. To measure cell proliferation, a cell proliferation assay was conducted, and absorption rate was measured through a 450 nm wavelength. CTA expression was measured through a quantitative polymerase chain reaction (quant-PCR). For this study, the expression rates of five CTAs were measured (TEX15, CEP55, CCNA1, P1A, SPA17). Apoptosis rate was measured through an Annexin-V assay, in which two markers, Annexin-V and 7-AAD, were used. We found that SB939 combined with 5-AzaC show highest efficacy compare to each drug alone in terms of inhibiting tumor cell proliferation, as well as inducing tumor cells apoptosis and enhancing tumor cell immunogenicity by the induction of the expression of CTAs. This combination proved to be effective in combating murine prostate cancer cells, and can potentially be effective within in vivo models due to its high toxicity to these cancer cells, and its ability to render prostate cancer more immunogenic.

cancer biology↗

bioRxiv2018

Determining the Quantitative Principles of T Cell Response to Antigenic Disparity: The Case of Stem Cell Transplant Donor-Recipient Exome Wide Mismatching and HLA Bound Alloreactive Peptides

Alloreactivity compromising clinical outcomes in stem cell transplantation is observed despite HLA matching of donors and recipients. This has its origin in the variation between the exomes of the two, which provides the basis for minor histocompatibility antigens (mHA). The mHA presented on the HLA class I and II molecules and the ensuing T cell response to these antigens results in graft versus host disease. In this paper, results of a whole exome sequencing study are presented, with resulting alloreactive polymorphic peptides and their HLA class I and HLA class II (DRB1) binding affinity quantified. Large libraries of potentially alloreactive recipient peptides binding both sets of molecules were identified, with HLA-DRB1 presenting an order of magnitude greater number of peptides. These results are used to develop a quantitative framework to understand the immunobiology of transplantation. A tensor-based approach is used to derive the equations needed to determine the alloreactive donor T cell response from the mHA-HLA binding affinity and protein expression data. This approach may be used in future studies to simulate the magnitude of expected donor T cell response and risk for alloreactive complications in HLA matched or mismatched hematopoietic cell and solid organ transplantation.

immunology↗