miRNA-21 inhibition suppresses the human epithelial ovarian cancer by targeting PTEN signal pathway

OBJECT: To explore the role of microRNA-21 in human epithelial ovarian cancer (EOC). METHODS: We used RT-PCR to test the expressions of miRNA-21 in EOC cells and normal ovarian epithelial cells, as well as the tumor samples and the tumor-adjacent normal tissues. The vector of LV3 pGLV-H1-GFP-miR-21 was used to decrease the level expression of endogenous miR-21 in cells. Further, we investigated how miR-21 affected the biological events of EOC through determining the changes in proliferation, cycle and invasion of EOC cells, and measured the tumorigenesis in xenograft models. The association between phosphatase and tensin homolog deleted on chromosome ten (PTEN) and miR-21 were tested by RT-PCR. Next, siRNA was used to knockdown PTEN gene which help us to assess the functional association between miR-21 and PTEN in vivo and in vitro. RESULTS: In EOC cell lines and human epithelial ovarian tumor cells, we found that miR-21 altered the biological features of EOC cells, including suppression of proliferation and invasion and arrest of cell cycle, and also resulted in a decrease in tumorigenesis in the in vitro xenograft models. The association between PTEN and miR-21 was confirmed in previous research. From our results, the down-regulation of PTEN gave rise to the miR-21 decrease, regardless of the cells or tissues. CONCLUSION: The suppression of microRNA-21 inhibits the progression of EOC profoundly. In EOC, miR-21 is negatively correlated with the expression of PTEN gene.