Downregulation of miR-485-3p promotes proliferation, migration and invasion in prostate cancer through activation of TGF-β signaling

Abstract

Background. Prostate cancer (PC) is the second leading cause of cancer-related death among men worldwide. Downregulation of miR-485-3p has been revealed to participate in the tumorigenesis and progression of many types of cancer. However, the clinical and biological role of miR-485-3p in PC remains largely unknown. Methods. The expression of miR-485-3p was analyzed in the published databases and detected in our clinical samples and cell lines by RT-qPCR assay. CCK8, transwell invasion and migration, and colony formation assays were performed to investigate the biological function of miR-485-3p. Bioinformatical analysis, RIP, western blotting and luciferase reporter assays were carried out to explore the downstream mechanism of miR-485-3p. Results. The level of miR-485-3p was downregulated in PC tissues, particularly in primary PC tissues with metastasis relative to normal prostate tissues. miR-485-3p downregulation was positively correlated with poor disease-free and overall survival in patients with PC. Functionally, miR-485-3p overexpression dramatically suppressed the proliferation, migration and invasion ability of PC cells in vitro. Mechanistically, miR-485-3p overexpression suppressed the activity of TGF-β signaling by targeting TGFBR2 to play tumor-suppressive roles in PC progression. Conclusion. Our study reports the miR-485- 3p/TGFBR2/ TGF-β signaling axis in tumor development of PC, suggesting miR-485-3p may be a potential target to develop therapeutic strategies against PC.