miR-126-5p Restoration Promotes Cell Apoptosis in Cervical Cancer by Targeting Bcl2l2

Abstract

Cervical cancer is one of the most common cancers in females, with a high incidence and mortality around the world. However, the pathogenesis in cervical cancer is not completely known. In the present study, we investigated the role of miR-126-5p and Bcl2l2 in cervical cancer cells. First, miR-126-5p expression was aberrantly downregulated in human cervical cancer tumor tissues in comparison with normal tissues, as evaluated by RT-PCR. Consistently, the levels of miR-126-5p were also significantly reduced in cervical cancer cell lines when compared to normal cervical epithelial cells. Flow cytometric analysis showed that the rate of apoptosis of cervical cancer cells was significantly increased by miR-126-5p overexpression but inhibited by miR-126-5p inhibitor. A similar change pattern was observed in the expression of apoptosis-regulated protein caspase 3 in cervical cancer cells transfected with miR-126-5p mimic or inhibitor. By bioinformatic prediction with online databases and verification using luciferase reporter assay, we then identified that Bcl2l2 is a direct target of miR-126-5p in cervical cancer cells. The expression of Bcl2l2 was strongly downregulated by the miR-126-5p mimic but upregulated by the miR-126-5p inhibitor in cervical cancer cells, and Bcl2l2 expression was significantly increased in human cervical cancer tumor tissues, which was negatively correlated with miR-126-5p levels. Furthermore, we confirmed that the rate of apoptosis was significantly increased by Bcl2l2 silencing in cervical cancer cells, which was not affected by the miR-126-5p inhibitor. In addition, the increased apoptosis of cells by the miR-126-5p mimic was inhibited by Bcl2l2 overexpression. In summary, miR-126-5p plays an inhibitory role in human cervical cancer progression, regulating the apoptosis of cancer cells via directly targeting Bcl2l2. This might provide a potential therapeutic target for cervical cancer.