目的：探究circ_0001429 通过调控miR-139-5p/ 转录生长因子影响因子1（TGF-interacting factor 1，TGIF1）分子轴对膀胱癌T24 细胞恶性生物学行为的影响。方法：采用qPCR实验检测circ_0001429 在膀胱癌细胞系SW780、T24、5637 和人膀胱上皮永生化细胞SV-HUC-1 中的表达水平，双荧光素酶报告基因实验验证miR-139-5p、circ_0001429 与TGIF1 之间的靶向调控关系；将T24 细胞分为NC组、sh-circ_0001429 组、miR-139-5p mimics 组、sh-TGIF1 组、pcDNA-circ_0001429+sh-TGIF1 组、miR-139-5p mimics+pcDNA-TGIF1 组以及sh-circ_0001429+miR-139-5p inhibitor 组，Western blotting 检测各组细胞中TGIF1 的表达水平，CCK-8 法、Transwell 实验和流式细胞术分别检测circ_0001429、miR-139-5p 和TGIF1 对T24 细胞增殖、侵袭、迁移和凋亡的影响。结果：circ_0001429 在3 珠膀胱癌细胞系中呈高表达（均P<0.01），敲降circ_0001429 可以显著抑制T24 细胞增殖、侵袭、迁移并促进细胞凋亡（P<0.05 或P<0.01）；双荧光素酶报告基因验证结果显示，circ_0001429 与miR-139-5p、miR-139-5p 与TGIF1 存在靶向关系；过表达miR-139-5p 显著抑制T24 细胞增殖、侵袭、迁移并促进细胞凋亡（均P<0.01）。回复实验进一步证实circ_0001429 和TGIF1 竞争性结合miR-139-5p 促进T24 细胞增殖、侵袭、迁移且抑制细胞凋亡（均P<0.01）。结论：circ_0001429 与TGIF1 竞争结合miR-139-5p 促进膀胱癌细胞T24 的增殖、侵袭、迁移且抑制细胞凋亡。

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 assay confirmed that there is a targeting relationship between circ_0001429 and miR-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.

湖北省自然科学基金面上项目资助（No. 2017CFB516；No. 2011CDB014）；湖北省卫生计生委面上项目资助（No. WJ2017M257）；湖北省卫生厅科研指导性项目资助（No. JX6C-62）