Up-regulation of miR-582-5p regulates cellular proliferation of prostate cancer cells under androgen-deprived conditions.

MicroRNAs are noncoding small RNA that negatively regulate target gene expression by binding to the 3'-UTR of mRNA. Previous studies have shown that several microRNAs play a pivotal role in prostate cancer by acting as oncogenes or tumor suppressors. This study was aimed at identifying microRNAs that contribute to the progression to castration resistant prostate cancer. MicroRNAs expression profiles of a xenograft model and cell lines were examined by microarray analysis and real-time PCR. Functional analysis of miR-582-5p in cellular proliferation was examined by cell counting. Furthermore, in order to investigate a candidate target of miR-582-5p, microarray analysis and analysis in silico were utilized. MiR-582-5p was identified to be up-regulated at the castration resistant stage of a xenograft model, KUCaP2 and in castration resistant cell line, AILNCaP#1. Overexpression of miR-582-5p increased the number and the percentage of S phase of LNCaP cells under androgen deprived condition. Moreover, suppression of miR-582-5p decreased the number and the percentage of S phase of AILNCaP#1 cells. Furthermore, we identified that miR-582-5p down-regulates EFNB2 expression, which is down-regulated at the castration resistant stage of a xenograft model, KUCaP2 and in castration resistant cell line, AILNCaP#1. Our results suggest that up-regulation of miR-582-5p contributes to an increase in the proliferation of prostate cancer cells under androgen deprived conditions.