Sitagliptin Inhibits Proliferation Of Bladder Cancer Cells Via Activating Hippo Pathway And Regulating The Expression Of Cathepsin B

Objective:Sitagliptin is a dipeptidyl peptidase 4(DPP4)inhibitor that improved glycemic control by inhibiting the degradation of glucagon-like peptide-1(GLP-1)in patients with type 2 diabetes.It has been reported that sitagliptin can inhibit the occurrence and epithelial cell transformation of breast cancer,and also has an inhibitory effect on colon cancer.However,there is no report on the effect of sitagliptin on bladder cancer.In this study,human bladder cancer cells T24 and 5637 were treated with different concentrations of sitagliptin,and then the viability of the cells was detected.In addition to,we have identified the role of the Hippo pathway in the progression of sitagliptin affecting bladder cancer proliferation.Finally,we explained the changes in cathepsin B(CTSB)during the inhibition of the proliferation of bladder cancer cells by sitagliptin and the effect of cathepsin B expression on cell proliferation.Method:1.T24 and 5637 cells were cultured in vitro,T24 cells treated with 0,0.3 m M,0.6 m M,1.2 m M sitagliptin,5637 cell treated with 0,0.5 m M,1.0 m M,1.5 m M sitagliptin for 24 h,48h,72 h,MTS and plate Cloning detects cell viability.2.Western blot was used to detect the changes of key proteins in the Hippo pathway and cathepsin B after sitagliptin treatment,including p-LATS909,p-YAP127 and CTSB.3.Immunofluorescence was used to detect the nuclear localization of YAP after sitagliptin treatment.4.RT-PCR was used to detect changes in YAP downstream target genes and CTSB m RNA changes after sitagliptin treatment.5.After the YAP inhibitor veterpofin or si RNA was used to reduce the activity of bladder cancer cell YAP,the m RNA and protein levels of CTSB were measured.6.After knocking down the expression of CTSB,cell proliferation was detected by CCK8,and apoptosis was detected by flow cytometry.Result:1.After treatment with different concentrations of sitagliptin for T24 and 5637,compared with the control group,the treatment group reduced cell viability,and the difference between the control group and the control group was statistically significant(P<0.05).2.After treatment of T24 and 5637 with sitagliptin,cells were collected at different time points.Western blot showed that p-LATS909 increased transiently and p-YAP127 continued to increase.After treatment with different concentrations of sitagliptin,p-YAP127 protein also increased,while cathepsin B protein expression decreased.3.After treatment with T24 and 5637 with sitagliptin,immunofluorescence results showed that the YAP nuclear localization was reduced in the treatment group compared with the control group.4.After treatment of T24 and 5637 with sitagliptin,RT-PCR results showed that the expression of target genes downstream of YAP was decreased,and the m RNA expression of CTSB was also decreased.5.After inhibiting YAP activity or knocking down YAP,the m RNA and protein levels of CTSB decreased.6.After knocking down the expression of CTSB,the proliferation of T24 and 5637 cells was significantly decreased,and the results of flow cytometry showed a significant increase in apoptosis.Conclusion:1.Sitagliptin inhibits the proliferation of bladder cancer cells.2.The Hippo pathway is activated during the inhibition of bladder cancer cell proliferation by sitagliptin.3.Sitagliptin reduced the expression of cathepsin B during the inhibition of bladder cancer cell proliferation.4.YAP regulates the m RNA and protein expression of cathepsin B.5.Decreased expression of cathepsin B increases apoptosis.