MiR-9 accelerates epithelial-mesenchymal transition of ovarian cancer cells via inhibiting e-cadherin.

Objective: To investigate the influence of micro-ribonucleic acid (miR)-9 on epithelial-mesenchymal transition (EMT) of ovarian cancer cells by targeted inhibition on E-cadherin (CDH1).

Methods: The human ovarian cancer cells were cultured and miR-9 was repressed by inhibitors and overexpressed by miRNA mimics. The expression of EMT-related proteins was measured via Western blotting (WB). The action target of miR-9 was determined through the dual-luciferase reporter gene assay. The changes in protein levels were detected using WB.

Results: The expression of miR-9 was markedly up-regulated in ovarian cancer tissues, that is, the expression level of serum miR-9 in ovarian cancer patients was higher than that in control group. After the inhibition of miR-9, the expression level of epithelial indicator CDH1 was increased, while that of interstitial indicator Vimentin was decreased. MiR-9 contained a complementary site in the 3'-untranslated region (UTR) of CDH1 messenger RNA (mRNA) and the mRNA and protein expressions of CDH1 in the cells were down-regulated obviously by miR-9 overexpression.

Conclusions: MiR-9 promotes the EMT of ovarian cancer cells through the targeted inhibition on CDH1.