MicroRNA-588 is upregulated in human prostate cancer with prognostic and functional implications.

Background: Epigenetic factors of microRNAs (miRNAs) are important biomarkers and modulators in human prostate cancer (PCa). In this work, we characterized the expression, biomarker-potential and functional regulation of miR-588 in PCa. Methods: Endogenous miR-588 levels were quantified by qRT-PCR in both prostate-specific antigen (PSA)-negative and PSA-positive PCa cell lines, as well as human PCa tumors. The associations between endogenous miR-588 and PCa patients' clinical outcomes and postoperative overall survival were statistically examined. Moreover, in both PSA-negative DU145 and PSA-positive LNCaP, downregulation of miR-588 was achived by transduction of miR-588 inhibitor lentivirus. The subsequent effects of miR-588 downregulation on PCa cell developments were investigated both in vitro and in vivo. Results: MiR-588 was profoundly upregulated in both PSA-negative and PSA-positive PCa cells, as well as in PCa tumors. Significant miR-588 upregulation was found to be closely associated with PCa patients' poor clinical outcomes and shorter postoperative overall survivals. In DU145 and LNCaP cell lines, lentiviral transduction markedly downregulated endogenous miR-588 levels. MiR-588 downregulation was shown to profoundly inhibit PCa proliferation in vitro and xenograft in vivo. Conclusion: Aberrant upregulation of endogenous miR-588 in PCa patients may be a prognostic biomarker, indicative of their poor clinical outcomes. Inhibiting endogenous miR-588 may also serve as a therapeutic target for PCa treatment. This article is protected by copyright. All rights reserved