Functional roles of miR-625-5p and miR-874-3p in the progression of castration resistant prostate cancer

Aims: Androgen receptor (AR) signaling is important in normal prostate and prostate tumor tissues. Thus, the new therapeutic strategies targeting ARs may also be important for treatment of prostate cancer (PC) and its biology. The studies have shown that miRNAs to be dysregulated in PC progression. Therefore, in the present study, differentially expressed miRNAs that predictively target the ARs were identified and investigated by in silico analysis. Main methods: Cellular proliferation, qPCR, western blot and apoptosis assays were performed to investigate the molecular mechanism of the selected miRNAs in the PC cells. Key findings: In our miRNA qPCR study, several miRNAs were found to be differentially regulated in castration resistant prostate cancer (CRPC) cells (LNCaP-Abl and LNCaP-104R2) compared with androgen dependent (AD) cells (LNCaP). The expression levels of miR-625-5p and miR-874-3p were significantly increased in LNCaP-Abl (2.62-fold, p = 0.0002; 4.00-fold, p = 0.00002, respectively) and LNCaP-104R2 (2.44-fold, p = 0.0455; 3.77 fold, p = 0.0383, respectively) compared with AD cells. The expression levels of AR and prostate specific antigen were increased in PC cells compared with AD cells. Furthermore, transfection of PC cells with anti-miRs suppressed their proliferation and AR protein levels (p < 0.05). Significance: Several differentially regulated miRNAs were identified in CRPC cells, including miR-625-5p and miR-874-3p that are potentially involved in PC progression. These results may provide novel insights into the molecular mechanism underlying CRPC cells and miRNA applications may constitute a new and alternative method to prevent development of CRPC cells in the future.

Automated summary

In this study, differentially expressed miRNAs that target androgen receptors (ARs) were identified and investigated in castration resistant prostate cancer (CRPC) cells. The expression levels of miR-625-5p and miR-874-3p were significantly increased in CRPC cells compared with androgen dependent cells, and transfection of CRPC cells with anti-miRs suppressed their proliferation and AR protein levels.