Effect of miRNA-186-3p on the function of cervical cancer CaSki cells and its relationship with transforming growth factor β-Smad signaling pathway / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the effect of miRNA-186-3p (miR-186-3p) on the apoptosis, immigration and invasion of cervical cancer CaSki cells and its relationship with transforming growth factor-β (TGF-β)-Smad signaling pathway.Methods:Plasmids containing miR-186-3p suppressor gene and miR-186-3p mimics were transfected into cervical cancer CaSki cells, namely miR-186-3p-I group and miR-186-3p-M group, respectively. In addition, CaSki cells transfected with empty plasmids were used as control (miR-186-3p-group C). Flow cytometry was used to detect the apoptosis rate of each group, and Transwell method was used to detect the migration and invasion ability of each group. Western blotting was used to detect the expression level of TGF-β-Smad signaling pathway related proteins. The target genes of miR-186-3p were predicted by using Starbase software and verified by using dual luciferase reporter gene assay.Results:The apoptosis rate of miR-186-3p-M group was lower than that of miR-186-3p-I group and miR-186-3p-C group [(7.5±3.2)% vs.(13.9±0.7)%, (12.7±0.6)%, all P < 0.05]. The number of migrating cells in miR-186-3p-M group [(218±25) vs. (168±13), (175±13), both P < 0.001] and the number of invasive cells in miR-186-3p-I group and miR-186-3p-C group were higher than those in miR-186-3p-I group and miR-186-3p-C group [(165±21) vs. (130±11), (142±12), all P < 0.001]. The relative expression levels of TGF-β, Smad2, Smad3, phosphorylated Smad2 (p-Smad2) and phosphorylated Smad3 (p-Smad3) in miR-186-3p-M group were the lowest, and the differences were statistically significant compared with the other two groups (all P < 0.001). Starbase software was used to predict the complementary binding of miR-186-3p to XIST RNA. Dual luciferase reporter assay showed that the relative luciferase activity of cells co-transfected with XIST wild-type vector and miR-186-3p mimic plasmid was lower than that of cells co-transfected with XIST wild-type vector and miR-186-3p empty plasmid ( P < 0.001). Conclusion:miR-186-3p may directly bind to XIST RNA and down-regulate the activity of TGF-β-Smad signaling pathway, thereby enhancing the immigration, apoptosis and invasion activities of cervical cancer CaSki cells.