N-myc downstream regulated gene 2 promotes apoptosis of bladder cancer cells through signal transducer and activator of transcription 3 signaling pathway / 中华泌尿外科杂志

ABSTRACT

Objective To investigate the effect of N-myc downstream regulated gene 2 (NDRG2) on the apoptosis of bladder cancer cells by regulating the signal transducer and activator of transcription 3(STAT3) signaling pathway.Methods The expression level of NDRG2 in human bladder cancer cell BIU-87 and immortalized cell SV-HUC-1 was detected by Western blot.NDRG2 over expression vector and empty vector control (pcDNA3.1),siRNA-NDRG2,siRNA control were transfected into BIU-87 cells.After transfected 48 h,the expression level of NDRG2,Cleaved caspase 3,STAT3,p-STAT3,JAK2,p-JAK2 were detected by Western blot,the cell proliferation and apoptosis were measured by MTT and flow cytometry.After adding inhibitor AG490 of 45 μmol/L in cultured BIU-87 cells,MTT assay was used to detect cell proliferation and flow cytometry was used to detect the cell apoptosis,Western blot to detect the expression level of Cleaved caspase 3,STAT3,p-STAT3,JAK2,p-JAK2.Results The expression level of NDRG2 in bladder cancer cells was higher than that in bladder epithelial cells.The cell survival rate of pcDNA3.1/NDRG2 group was lower than that of pcDNA3.1 group,the difference was statistically significant (P ＜ 0.01).The cell survival rate of siRNA-NDRG2 group was higher than that of siRNA control group (P＜ 0.01).The apoptosis rate of pcDNA3.1/NDRG2 group was higher than that of pcDNA3.1 group (P ＜ 0.01).The apoptosis rate of NDRG2 siRNA group was lower than that of siRNA control group (P ＜ 0.01).The level of p-STAT3 and p-JAK2 in pcDNA3.1/NDRG2 group was lower than that in pcDNA3.1 group (P＜ 0.01).The survival rate and apoptosis rate of BIU-87 cells cultured with AG490 were in agreement with the trend of pcDNA3.1/NDRG2 after transfection.Conclusions NDRG2 could promote the apoptosis of bladder cancer cells,and its mechanism may be related to STAT3 signaling pathway.