硼替佐米对K562/DNR细胞株MAPK信号途径的影响

本研究旨在检测硼替佐米对柔红霉素（daunorubicin,DNR）诱导的K562耐药细胞株K562/DNRMAPK信号途径中ERK、JNK及P38的影响,探讨硼替佐米逆转白血病细胞耐药的分子机制。应用四甲基偶氮唑盐微量酶反应比色法（MTT法）进行耐药细胞株和硼替佐米细胞毒性的判定。选用4μg/L硼替佐米作为实验用药,以100μg/mlDNR单用或联合应用硼替佐米作用于K562/DNR细胞株12、24和36小时,应用Western blot检测不同时间点各组ERK、JNK、p38及P-gp的表达水平,同时应用流式细胞术检测各组细胞凋亡率。结果表明,与DNR组相比,在总ERK1/2、p38及JNK无明显变化的情况下,硼替佐米联合DNR可抑制P-ERK、P-P38的表达,增加P-JNK的表达（p〈0.05）,同时减少P-gp表达,其作用随作用时间延长而增强,同时加用硼替佐米可增加细胞凋亡率。结论：硼替佐米可通过MAPK信号通路逆转白血病细胞耐药性,增加细胞凋亡率,该作用呈时间依赖性。

Effect of Bortezomib on MAPK Signaling Pathway of K562/DNR Cells

The study was aimed to investigate the effects of bortezomib（BTZ） on the expression of ERK,JNK and P38 in daunorubicin（DNR）-resistant K562 cells （K562/DNR） and to clarify the molecular mechanism of BTZ in rever-sing the drug-resistance in leukemic cells. The K562/DNR cells and the cellular toxicity of BTZ was determined by MTT,then 4 μg/L of BTZ was chosen to do the experiment. The expression of ERK,JNK,p38 and P-gp of K562/DNR cells treated with DNR only or DNR combined with BTZ for 12,24 and 36 hours was detected by Western blot. The apoptosis rate in each group was assayed by flow cytometry. The results showed that as compared with DNR group,the expression of P-ERK,P-P38 and P-gp was significantly suppressed（p0.05） and the expression of P-JNK was significantly enhanced（p0.05） in the cells treated with DNR combined with BTZ. There was no change in the expression of total ERK,P38 and JNK. The effect increased with the prolonging of time. Meanwile,the apoptosis rate in cells treated with DNR combined with BTZ increased compared with DNR only. It is concluded that the BTZ can reverse the drug resistance in K562/DNR cells by MAPK signaling pathway and increase the apoptosis of leukemic cells. The effect shows the characteristics of time-dependent manner.