硼替佐米作用不同时间对K562耐药细胞株核因子-κ B途径的影响

目的 观察硼替佐米(商品名:万珂,PS-341)对柔红霉素(DNR)诱导的K562耐药细胞株(K562/DNR)核因子-κ B(NF-κ B)、抑制蛋白κ B(I κ B)及P-糖蛋白(P-gp)表达的影响,探讨PS-341逆转耐药的分子机制.方法 以100μg/ml DNR单用或联合应用4μg/L PS-341分别作用于K562/DNR 12、24及36 h,检测不同时间点各组NF-κ B、Iκ B及P-gp表达情况,同时测定NF-κ B p65活性,检测各组细胞凋亡率.结果 Western blot结果显示:与阴性对照组相比,DNR可诱导NF-κ B表达上调及活性增强、I κ B表达下调、P-gp表达上凋;加用PS-341可显著抑制DNR诱导的NF-κ B及P-gp表达,使I κ B表达增加.加用PS-341后,NF-κ B活性12 h为(15.3±1.87)%DNR组为(23.8±2.27)%],24 h为(10.2±1.69)%DNR组为(25.4±1.98)%],36 h为(6.08±2.53)%DNR组为(26.9±2.58)%],与相应单用DNR组相比均有明显下降,差异有统计学意义(P值均＜0.05).DNR与PS-341联用后,细胞凋亡率12 h为(35.23±5.15)%DNR组为(15.56±4.12)%],24 h为(40.26±6.89)%DNR组为(17.25±2.89)%],36 h为(43.58±7.69)%DNR组为(22.47±4.58)%],与DNR组相比,细胞凋亡率均明显增加,差异具有统计学意义(P值均＜0.05).上述作用呈时间依赖性.结论 PS-341可减少K562/DNR细胞NF-κ B的活化,降低P-gp表达,逆转细胞耐药,促进细胞凋亡.

Effects of different time points of bortezomib on the pathway of NF-κB in drug-resistant K562 cells

Objective To study the effects of bortezomib on the expression of NF-κB, IκB and P-gp of drug-resistant K562 cells induced by daunorubicin (K562/DNR), to explore the molecular mechanism of drug-resistant reverse. Methods The expression of NF-κB, IκB and P-gp in K562/DNR cells were detected when the cells had been treated with 100 μg/ml DNR only or together with 4 μg/L bortezomib for 12 h, 24 h and 36 h. The apoptosis rates were detected in each group respectively and the activity of NF-κB was detected by ELISA method. Results Compared with the control group, the expressions of NF-κB and P-gp in K562/DNR could be increased and IκB was decreased after being treated with DNR. When K562/DNR were cultured with bortezomib, the expressions of NF-κB and P-gp induced by DNR were significantly suppressed and IκB was increased. The activity of NF-κB were detected in different time points: (15.3±1.87) %(23.8± 2.27) % in DNR group] at 12 h, (10.2±1.69) % (25.4±1.98) % in DNR group] at 24 h, (6.08±2.53) % (26.9±2.58) % in DNR group] at 36 h. There were a significant differences between DNR group and DNR+PS-341group. The apoptosis rates were increased in DNR+PS-341 group at different time points than those in DNRgroup, (35.23±5.15) % (15.56±4.12) % in DNR group] at 12 h, (40.26±6.89) % (17.25±2.89) % in DNR group] at 24 h, (43.58±7.69) % (22.47±4.58) % in DNR group] at 36 h. The effccts showed the character of time-dependent pattern. Conclusion Bortezomib could downregulate the expressions of NF-κB and P-gp in K562/DNR, reverse the drug resistance and up-regulate the apoptotic rates in K562/DNR cells.