[MicroRNA-133b suppresses cell proliferation and invasion of esophageal squamous cell carcinoma via downregulating TAGLN2 expression].

Objective: To investigate the expression of microRNA-133b (miR-133b) in esophageal squamous cell carcinoma (ESCC), and explore its effect and the underlying molecular mechanisms on cell proliferation and invasion. Methods: Real-time quantitative PCR (qPCR) was used to examine miR-133b expression in 63 ESCC tissues and paired adjacent non-cancerous tissues, several ESCC cells (Eca109, EC9706, EC1, TE1, KYSE70) and normal esophageal epithelial cell Het-1A. MiR-133b mimic, inhibitor and negative control (NC) were transfected into TE1 cells. The effect of miR-133b on cell proliferation and invasion were determined by CCK-8 and Transwell assays, respectively. Subsequently, the target gene of miR-133b was predicted by online tools TargetScan and miRDB, which was verified by dual luciferase reporter assays. Finally, Western blot was utilized to detect the effects of miR-133b overexpression on expression of target gene TAGLN2 as well as EMT-related proteins E-cadherin, N-cadherin, Snail, Slug and Vimentin. Results: Relative levels of miR-133b in ESCC tissues (0.295±0.040) were significantly lower than those in adjacent non-cancerous tissues (1.002±0.011, P 0.05). Furthermore, miR-133b overexpression markedly downregulated TAGLN2, N-cadherin, Snail, Slug and Vimentin levels, and increased E-cadherin expression. Conclusion: MiR-133b plays an important role in the proliferation and invasion of ESCC cells by regulating TAGLN2 expression, and it may be a potential therapeutic target for ESCC patients.