lncRNA MGP-AS2 Inhibits the Progression of Bladder Cancer Through the miR-18a/Wnt/β-catenin Axis
Objective To explore the relationship between the expression of lncRNA MGP-AS2 in bladder cancer tissues and the survival of bladder cancer patients,and to study the impact of MGP-AS2 on the biological function of bladder cancer cells and possible mechanism.Methods The TANRIC database was used to analyze MGP-AS2 expression level in bladder cancer tissues and its relation-ship with patient survival.Real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect the expression level of MGP-AS2 in bladder cancer cell lines.The MGP-AS2 overexpression plasmid and negative control(NC)plasmid were transfected into bladder cancer 5637 cells,respectively,as the MGP-AS2group and NC group.Plate cloning experiment,cell scratch experiment and Tr-answell experiment were used to analyze the effects of MGP-AS2 overexpression on the proliferation,migration and invasion of bladder cancer 5637 cells.Dual-luciferase reporter gene experiment was used to verify the targeted binding between MGP-AS2 and miR-18a.The TANRIC database was used to analyze the correlation between MGP-AS2 and miR-18a expression.RT-qPCR method was used to analyze the effect of MGP-AS2 overexpression on the expression of miR-18a in bladder cancer 5637 cells.Western blot method was used to detect the effect of MGP-AS2 overexpression on the expression of Wnt/β-catenin signaling pathway proteins in bladder cancer 5637 cells.Results The expression level of MGP-AS2 in bladder cancer tissue was significantly lower than that in normal bladder tis-sues(P<0.01).The overall survival and disease-free survival of patients with high expression of MGP-AS2 were significantly longer than those of patients with low expression of MGP-AS2(P<0.01).The expression level of MGP-AS2 in bladder cancer cell lines were lower than those in SV-HUC-1 cells(P<0.05).The bladder cancer cells with the lowest MGP-AS2 expression was 5637 cells(P<0.01).Compared with the NC group,overexpression of MGP-AS2 could significantly inhibit the proliferation,migration and invasion a-bility of 5637 cells(P<0.01).Dual-luciferase reporter gene experiment confirmed that MGP-AS2 could target and bind to miR-18a(P<0.01).Compared with the NC group,overexpression of MGP-AS2 could downregulate the expression of miR-18a(P<0.01).After overexpression of MGP-AS2,Wnt/β-catenin signaling pathway proteins were all down-regulated in bladder cancer 5637 cells(P<0.01).Conclusion MGP-AS2 is low-expressed in bladder cancer,and the expression level of MGP-AS2 is correlated with the prognosis of bladder cancer patients.MGP-AS2 may inhibit the transduction of the Wnt/β-catenin signaling pathway by adsorbing miR-18a,thereby inhibiting the progression of bladder cancer.