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

Abstract

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.