Abstract 398: Epigenetic changes in testis specific Y-like 5 gene in human prostate carcinoma: Gene expression analysis and its potential as a biomarker

Abstract

Abstract INTRODUCTION Testis specific Y-like protein (TSPYL-5) is a member of TSPY-L family of gene, whose functions are currently unknown. TSPYL-5 was reported to possess tumor suppressor function and a target for epigenetic silencing in human glioblastoma and colon carcinoma. The exact nature of TSPYL-5 gene expression and its epigenetic modification is not known in prostate carcinoma. We hypothesize that this gene could be expressed in prostate carcinoma cells and tissues and its methylation status could function as an epigenetic biomarker for aggressive prostate cancer phenotype. MATERIALS AND METHODS Human prostate carcinoma cells (PC3, DU145, LnCAP) was grown in DMEM-F12 media with 10% FBS at 37oC. Normal prostate epithelial cells (RWPE1-) were maintained in keratinocyte serum free media. Total RNA was extracted from the cells and converted to cDNA which served as a template for PCR amplification in the presence of TSPYL-5 gene primers. The amplified PCR products were analyzed by 2% agarose gel electrophoresis. Methylation-specific PCR (MSP) was performed with primers designed for the CpG island in the gene promoter to detect the methylation changes in the carcinoma cells. RESULTS Quantitative RT-PCR analysis of TSPYL-5 gene expression in different human prostate carcinoma cells lines identified 2-3 fold higher expression (P ≤ 0.005) in lines with metastatic propensity (PC3) compared to less aggressive ones. MSP analysis indicated differential promoter methylation of TSPYL-5 gene in carcinoma and normal prostate epithelial cells (RWPE1). Consistent methylation in LnCAP and DU145 cells was observed in our experiments and was associated with reduced expression of the gene. CONCLUSIONS Expression of TSPYL-5 is higher in human prostate carcinoma cells derived from more metastatic phenotype. This expression could be influenced by DNA methylation. It is not clear whether TSPYL-5 expression in prostate carcinoma cells could play a part in tumor suppressor function. Alternately, the presence of this gene may play alternate roles including treatment resistance and cell growth. Further, DNA methylation of the CpG island of TSPYL-5 could serve as a robust biomarker of aggressive phenotype in human prostate carcinoma. Citation Format: Senthil R. Kumar, Jeffrey Bryan, Magda Esebua. Epigenetic changes in testis specific Y-like 5 gene in human prostate carcinoma: Gene expression analysis and its potential as a biomarker. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 398. doi:10.1158/1538-7445.AM2014-398