Abstract 4093: miR-193b is an epigenetically regulated putative tumor suppressor in prostate cancer

Abstract

Abstract miRNAs have proven to be key regulators of gene expression and are differentially expressed in various diseases, including cancer. Our aim was to identify epigenetically dysregulated genes in prostate cancer. We performed miRNA expression profiling after relieving epigenetic modifications in six prostate cancer cell lines and non-malignant prostate epithelial cells. 38 miRNAs showed increased expression in any prostate cancer cell line after 5-aza-2′-deoxycytidine (5azadC) and trichostatin A (TSA) treatments. Six of these also had decreased expression in clinical prostate cancer samples compared to benign prostatic hyperplasia. Among these, miR-193b was methylated in 22Rv1 cell line at a CpG island ∼1kb upstream of the miRNA locus. Expressing miR-193b in 22Rv1 cells using pre-miR-193b oligonucleotides caused a significant growth reduction (p<0.001) resulting from a decrease of cells in S-phase of the cell cycle (p<0.01). In addition, the anchorage independent growth was partially inhibited in transiently miR-193b -expressing 22Rv1 cells (p<0.01). Altogether, our data suggest that miR-193b is an epigenetically silenced putative tumor suppressor in prostate cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4093.