MiR-592 represses FOXO3 expression and promotes the proliferation of prostate cancer cells.

Prostate cancer (PC) is a serious health problem all over the world. Cell proliferation plays a major role in the tumorigenesis of PC. It is reported that microRNAs (miRNAs) played crucial roles in the regulation of cell proliferation. However, the underlying mechanism of miRNAs in PC has not been intensively investigated. In the present study, the effect of miR-592 on the cell proliferation of PC was investigated. The results showed that miR-592 was significantly upregulated in PC cell and PC tissues. To investigate the biological roles of miR-592, we induced either the up- or downregulation of miR-592 expression by transfecting DU145 PC cells with miR-592 mimics or miR-592 inhibitor. Our results demonstrated that the upregulation of miR-592promoted cell growth, while miR-592 inhibitor showed the opposite effect. Further experiment revealed that miR-592 repressed the expression of FOXO3 by directly targeting the 3'UTR of the FOXO3 transcript, which resulted in upregulating of the expression of cyclin D1 and downregulating of the expression of p21. In sum, our data indicated a novel aspect of the miR-592 in the molecular etiology of PC.