MicroRNA-506-3p inhibits proliferation and promotes apoptosis in ovarian cancer cell via targeting SIRT1/AKT/FOXO3a signaling pathway

Xiao-Yan Xia, You-Jun Yu, Feng Ye, Gui-Yuan Peng, Yao-Jun Li,  Xiao-Ming Zhou

Abstract:

Ovarian cancer (OC) is one of the most common tumors in females. Growing evidence shows that microRNA-506-3p (miR-506-3p) is downregulated in OC tissues. The purpose of this study was to investigate the mechanism of miR-506-3p in modulating OC. Quantitative reverse transcriptase PCR (qRT-PCR) was employed to investigate the expression of miR-506-3p and its target in OC tissues or cell lines. CCK-8 or colony formation assay was used to examine cell viability or proliferation, respectively. Flow cytometry was demonstrated to detect cell apoptosis. Western blot was then applied to analyze underlying mechanisms. The potential target of miR-506-3p was examined via luciferase reporter assay. MiR-506-3p was significantly downregulated in both human OC tissues and cell lines. Overexpression of miR-506-3p not only decreased cell viability of OC cell lines but also promoted cell apoptosis, thus inhibiting OC progression. Moreover, SIRT1 (Sirtuin 1) was found to be a direct target of miR-506-3p, and SIRT1 expression was negatively regulated by miR-506-3p in OC cell lines. Further investigation revealed that overexpression of SIRT1 could promote cell viability as well as inhibit cell apoptosis, showing the reversed effect on OC progression compared to miR-506-3p. Lastly, AKT (Protein kinase B) /FOXO3a (Forkhead box O3) signaling pathway was inactivated by miR-506-3p while activated by SIRT1, relating to regulation of miR-506-3p on OC progression. Our results revealed a novel mechanism by which miR-506-3p inhibited proliferation while promoted apoptosis of OC via inactivation of SIRT1/AKT/FOXO3a signaling pathway, suggesting that miR-506-3p might be a potential target for OC.