ABSTRACT
@#[Abstract] Objective: To explore the effect of circ_0001429 on proliferation and apoptosis of bladder cancer cells by regulating miR-139-5p/TGF-interacting factor 1（TGIF1）axis. Methods: The expression of circ_0001429 in bladder cancer cell lines SW780, T24, 5637 and human bladder epithelial SV-HUC-1 cells were detected by RT-qPCR. Targeted regulatory relationship between circ_0001429 and miR-139-5p as well as miR-139-5p and TGIF1 was measured by Dual luciferase reporter gene assay. T24 cells were divided into NC group, sh-circ_0001429 group, miR-139-5p mimics group, sh-TGIF1 group, pcDNA-circ_0001429+sh-TGIF1 group, miR-139-5p mimics+pcDNA-TGIF1 group and sh-circ_0001429+miR-139-5p inhibitor group. Western blotting was used to detect the expression level of TGIF1 in each group. CCK-8 method, Transwell experiment and Flow cytometry were used to detect the effects of circ_ 0001429, miR-139-5p and TGIF1 on proliferation, invasion, migration and apoptosis of T24 cells, respectively. Results: Circ_0001429 was highly expressed in three bladder cancer cell lines (P<0.01). Knockdown of circ_0001429 significantly inhibited proliferation, invasion and migration of T24 cells while promoted the level of cell apoptosis (P<0.05 or P<0.01). The results of Dual luciferase reporter gene assayconfirmedthatthereisatargetingrelationshipbetweencirc_0001429andmiR-139-5p as well as between miR-139-5p and TGIF1. Overexpression of miR-139-5p significantly inhibited the proliferation, invasion and migration of T24 cells while promoted the level of cell apoptosis (all P<0.01). Recovery experiments further confirmed that the competitive binding of circ_0001429 and TGIF1 to miR-139-5p promoted the proliferation, invasion and migration of T24 cells while inhibited the level of cell apoptosis (all P<0.01). Conclusion: Circ_0001429 promotes proliferation, invasion and migration and inhibits apoptosis of bladder cancer T24 cells by competing with TGIF1 to bind to miR-139-5p.