慢病毒介导的Aurora A沉默对耐阿霉素人膀胱癌细胞凋亡的影响及机制

Silencing of Aurora A induces apoptosis and enhances chemosensitivity of adriamycin-resistance in human bladder cancer cells through down-regulation of MRP-1 and Bcl-2

目的探讨Aurora A在人膀胱癌细胞耐阿霉素(ADM)形成机制中的作用及影响。方法采用ADM浓度梯度递增诱导法建立ADM人膀胱癌T24细胞株(T24/ADM),MTT法检测不同浓度ADM(1μg/mL和2μg/mL)对T24和T24/ADM细胞的毒性作用,分别构建转染Aurora A RNAi慢病毒和空载体的T24/ADM细胞(T24/ADM/KD和T24/ADM/NC),2μg/mL阿霉素分别处理T24/ADM、T24/ADM/NC和T24/ADM/KD细胞24 h,Annexin V-FITC/PI和Western blot分别检测各组细胞凋亡率和MRP-1、Bcl-2蛋白表达水平。结果随着ADM浓度增加(2μg/mL ADM处理),T24/ADM细胞耐ADM的细胞毒性作用(22.8±2.0%)较T24细胞(52.5±11.6%)更加明显(P=0.035)。2μg/mL ADM作用于T24/ADM、T24/ADM/NC和T24/ADM/KD细胞24 h后,Annexin V-PE检测各组细胞的凋亡率分别为(6.61±0.44)%、(6.76±0.39)%和(24.43±1.77)%,T24/ADM和T24/ADM/NC细胞间的凋亡率比较,差异无统计学意义(P=0.88);T24/ADM/KD细胞的凋亡率较T24/ADM和T24/ADM/NC细胞显著增加(P<0.01)。2μg/mL ADM作用于T24/ADM、T24/ADM/NC和T24/ADM/KD细胞24 h后,Western blot检测显示T24/ADM/KD细胞的MRP-1和Bcl-2蛋白表达水平均低于T24/ADM和T24/ADM/NC细胞(P<0.05);T24/ADM与T24/ADM/NC细胞的MRP-1(P=0.92)和Bcl-2(P=0.31)蛋白表达水平比较,差异无统计学意义(P=0.31)。结论Aurora A可能通过调控MRP-1和Bcl-2的表达,影响T24/ADM细胞的凋亡和对阿霉素的耐药性,其在膀胱癌多药耐药的形成中可能发挥着重要作用。

Objective This study was designed to explore the role of Aurora A in the molecular mechanisms of multidrug resistance(MDR)of human bladder cancer cells.Methods Adriamycin(ADM)-resistance T24 cells(T24/ADM)was generated from T24 cells cultured within gradual increasing concentration of ADM.MTT assays was underwent to detect cells viability of T24 and T24/ADM cells treated with 1μg/mL and 2μg/mL ADM for 24 hours.The apoptosis and protein expression of T24/ADM,T24/ADM/NC and T24/ADM/KD was evaluated respectively by Annexin V-FITC/PI assay and Western blot.Results With the increase of ADM concentration(2μg/mL ADM treatment),the ADM-resistant cytotoxicity of T24/ADM cells(22.8±2.0%)was more obvious than that of T24 cells(52.5±11.6%)(P=0.035).Annexin V-PE was treated with μg/mL ADM on T24/ADM,T24/ADM/NC and T24/ADM/KD cells for 24 h.There was no significant difference in the apoptosis rates between T24/ADM and T24/ADM/NC cells(P=0.88).The apoptosis rate of T24/ADM/KD cells was significantly higher than that of T24/ADM and T24/ADM/NC cells(P<0.01).The 2μg/mL ADM was applied to T24/ADM,T24/ADM/NC and T24/ADM/KD cells for 24 h.The protein expression levels of MRP-1 and Bcl-2 in T24/ADM/KD cells were lower than those in T24/ADM and T24/ADM/NC cells(P<0.05).There was no significant difference in MRP-1(P=0.92)and Bcl-2(P=0.31)protein expression levels between T24/ADM and T24/ADM/NC cells(P=0.31).Conclusions Aurora A may affect apoptosis and adriamycin resistance of 124/ADM cells by regulating MRP-1 and Bcl-2 expression,and may play an important role in the formation of multidrug resistance in bladder cancer.