Abstract: Objective To investigate the role of RNA-binding motif protein X- linked (RBMX) in regulating the proliferation, migration, invasion and glycolysis in human bladder cancer cells. Methods A lentivirus vectors system and RNA interference technique were used to construct bladder cancer 1376 and UC-3 cell models with RBMX overexpression and knockdown, respectively, and successful cell modeling was verified using RT-qPCR and Western blotting. Proliferation and colony forming ability of the cells were evaluated using EdU assay and colony- forming assay, and cell migration and invasion abilities were determined using Transwell experiment. The expressions of glycolysis- related proteins M1 pyruvate kinase (PKM1) and M2 pyruvate kinase (PKM2) were detected using Western blotting. The effects of RBMX overexpression and knockdown on glycolysis in the bladder cancer cells were assessed using glucose and lactic acid detection kits. Results RT-qPCR and Western blotting confirmed successful construction of 1376 and UC-3 cell models with RBMX overexpression and knockdown. RBMX overexpression significantly inhibited the proliferation, clone formation, migration and invasion of bladder cancer cells, while RBMX knockdown produced the opposite effects. Western blotting results showed that RBMX overexpression increased the expression of PKM1 and decreased the expression of PKM2, while RBMX knockdown produced the opposite effects. Glucose consumption and lactate production levels were significantly lowered in the cells with RBMX overexpression (P<0.05) but increased significantly following RBMX knockdown (P<0.05). Conclusion RBMX overexpression inhibits bladder cancer progression and lowers glycolysis level in bladder cancer cells by downregulating PKM2 expression, suggesting the potential of RBMX as a molecular target for diagnosis and treatment of bladder cancer.

Key words: RNA-binding motif protein X-linked; M2 pyruvate kinase; bladder cancer; PKM2; glycolysis