The Effect Of O-GlcNAc Glycosylation Hydrolase Inhibitor Combined With Oxaliplatin On Proliferation And Apoptosis Of Bladder Cancer EJ Cell Line

Objective:Chemotherapy has become a common auxiliary treatment of bladder cancer at present.However, the postoperative recurrence and progression rate still didn't get a lot of change. Therefore, it is of great significance to explore more effective chemotherapy drugs at the same time of surgical treatment for bladder cancer. The aim of this study is to investigate the effect of Thiamet-G(O-Glc NAc glycosylation hydrolase inhibitor)combined with oxaliplatin on proliferation and apoptosis of bladder cancer EJ cell lines in vitro. And try to explore the possible mechanism, which will provide basic research for improvement of bladder cancer chemotherapy.Methods:Culture EJ cells in vitro and divided into four groups: blank control,Thiamet-G-treated, oxaliplatin-treated and combination group. Chosing the logarithmic phase of cells for experiment. First of all, observe the cell proliferation condition after treated with different drugs(MTT method, CCK-8 method,monoclonal method); Second, using the flow cytometry to observe the cell cycle and cell apoptosis; Finally, using Western Blot Technology to observe the expression of Caspase-3, Caspase-9 and the pro-apoptotic protein Bax and anti-apoptotic protein Bcl-2.Results:1. There is little significance on proliferation when treated EJ cells with Thiamet-G alone. But cell proliferation was significantly inhibited when using oxaliplatin alone or combined with Thiamet-G, the difference was statistically significant(p< 0.05)when compared with blank control. They showed time-effect and concentration-effect relationships within a certain range. And the proliferation inhibition rate was obviously different(p < 0.05) compared as combination group v.s. oxaliplatin- treated group.2. Flow cytometry results showed that, 48 h after treated with different drugs, the combination application of the two drugs increased the apoptosis rate of EJ cells significantly than using oxaliplatin alone(31.45±1.18% v.s. 13.02±0.96%, p< 0.05), and cell proliferation is blocked in S phase.4. Western Blot technology revealed that Thiamet-G has no effect on various proteins expression. The expression of Caspase-3, Caspase-9 increased significantly after treated with oxaliplatin. In combination of the two drugs, the effect is more obvious.And the expression of Bax increased significantly when compared combination group with oxaliplatin group, while the expression of anti-apoptotic protein Bcl-2 showed no significant change.Conclusion:1. As the OGA inhibitor, Thiamet-G alone has no obvious effect on EJ cells.2. Oxaliplatin can inhibit proliferation and promote apoptosis of bladder cancer EJ cells. The effects showed time-effect and concentration-effect relationships within a certain range.3. Thiamet-G can enhance the killing effect of oxaliplatin to EJ cells significantly. It sensitizes EJ cells to oxaliplatin.4. The effect of apoptosis on EJ cells caused by oxaliplatin may be related to the activation of caspase-3, caspase-9 cascade reactions, and may be associated with the enhanced Bax expression. The specific mechanism still needs further research to clarify.