Cariporide降低K562/DOX细胞株表达P-糖蛋白而逆转耐药的影响

 目的 探讨cariporide对耐药细胞株K562/DOX中P-糖蛋白（P-glycoprotein，P-gp）的影响，为抗白血病多药耐药（multidrug resistance, MDR）提供新方法。方法 应用cariporide对细胞进行酸化，应用激光共聚焦显微镜测定野生型细胞系K562及耐药细胞株K562/DOX细胞内pH值及细胞酸化对K562和K562/DOX细胞内阿霉素累积的影响。采用MTT法观察细胞酸化对细胞活力的影响。应用流式细胞术检测细胞酸化对K562/DOX细胞中P-gp功能的影响。采用实时定量RT-PCR技术检测MDR1基因在mRNA表达水平的变化。结果 Cariporide处理3 h对K562及K562/DOX细胞的活力影响较小。在K562/DOX细胞中，P-gp的外排药物能力随细胞内pH值的降低而减弱，cariporide明显增加了细胞对罗丹明123（rhodaminel 123，Rh123）和阿霉素的累积。细胞酸化还在mRNA水平抑制了K562/DOX细胞中P-gp的表达。结论 Cariporide能够抑制K562/DOX耐药细胞株中MDR1基因表达和P-gp的功能。

Effect of Cariporide on P-glycoprotein to Reverse Multidrug Resistance in K562/DOX Cells

OBJECTIVE To investigate the effect of cariporide on the P-gp in K562/DOX cells.METHODS Confocal laser microscope was used to determine the intracellular pH of the cells, which was also used to detect the accumulation of Rh123 and doxorubicin. MTT assay used for determining the cytotoxicity of cariporide on K562 and K562/DOX cells.Flow cytometry was applied to detect the influence of intracellular acidification on the activity of P-gp.By using Real-time RT-PCR，the influence of cariporide on P-gp expression at mRNA levels were determined.RESULTS The results indicated that cariporide had no obvious cytotoxicity on K562 and K562/DOX cells, and it reduced the MDR1 expression in K562/DOX cells.It was further shown that the decrease of P-gp activity was associated with a significant increased accumulation of Rh123 and doxorubicin in K562/DOX cells.CONCLUSION The data indicated that cariporide could reserve the MDR of K562/DOX cells through down-regulation of P-gp activity and MDR1 expression.