MicroRNA-491-5p (miR-491-5p) has been implicated in several cancers; however, its role in human prostate cancer (PCa) remains unknown. In this study, we observed downregulation of miR-491-5p expression in PCa tissues and cell lines. CCK-8 and EdU assays showed that forced expression of miR-491-5p suppressed PCa cell proliferation, which was further confirmed in a cell cycle assay. Overexpression of miR-491-5p also reduced PCa cell migration and invasion abilities as indicated by Transwell assays. Additionally, miR-491-5p overexpression significantly inhibited PCa growth in a mouse xenograft model. Mechanistically, platelet-derived growth factor receptor α (PDGFRA) was found to be a novel target of miR-491-5p. Re-introduction of PDGFRA antagonized the inhibitory effects of miR-491-5p on the proliferation and motility abilities of PCa cells. In clinical samples of PCa, miR-491-5p was negatively correlated with PDGFRA expression, which was upregulated in PCa. Collectively, these results demonstrate that miR-491-5p acts as a tumor suppressor in PCa by directly targeting PDGFRA and may serve as a therapeutic biomarker for patients with PCa.
Keywords: miR-491-5p; motility; platelet-derived growth factor receptor α; proliferation; prostate cancer.