Regulation of E3 ubiquitin ligase-1 (WWP1) by microRNA-452 inhibits cancer cell migration and invasion in prostate cancer

Background: MicroRNA-224 (miR-224) and microRNA-452 (miR-452) are closely located on the human chromosome Xq28 region. miR-224 functions as a tumour suppressor by targeting tumour protein D52 (TPD52) in prostate cancer (PCa). Here, we aimed to investigate the functional significance of miR-452 in PCa cells. Methods: Functional studies of PCa cells were performed using transfection with mature miRNAs or siRNAs. Genome-wide gene expression analysis, in silico analysis, and dual-luciferase reporter assays were applied to identify miRNA targets. The association between miR-452 levels and overall patient survival was estimated by the Kaplan–Meier method. Results: Expression of miR-452 was significantly downregulated in PCa tissues. Transfection with mature miR-452 inhibited the migration and invasion of PCa cells. Kaplan–Meier survival curves showed that low expression of miR-452 predicted a short duration of progression to castration-resistant PCa. WW domain-containing E3 ubiquitin protein ligase-1 (WWP1) was a direct target of miR-452, and knockdown of WWP1 inhibited the migration and invasion of PCa cells. WWP1 was upregulated in PCa clinical specimens. Conclusions: Regulation of the miR-452–WWP1 axis contributed to PCa cell migration and invasion, and elucidation of downstream signalling of this axis will provide new insights into the mechanisms of PCa oncogenesis and metastasis.