白血病耐药细胞中葡萄糖神经酰胺合成酶经ERK信号转导通路对P-gp表达的影响  

Effect of glucosylceramide synthase on P-gp expression by ERK signal transduction pathway in leukemia multidrug resistance cell line

作　　者：李玉玲[1] 谢可鸣[1] 张杨杨[1] 穆会君[2] 张滨[2] 邹健[2] 谢平[2] 

机构地区：[1]江苏省苏州大学医学部病理生理学教研室,215123 [2]无锡市人民医院中心实验室

出　　处：《中华医学遗传学杂志》2012年第3期270-274,共5页Chinese Journal of Medical Genetics

摘　　要：目的探讨葡萄糖神经酰胺合成酶（glucosylceramidesynthase，GCS）在白血病细胞耐药形成过程中是否经过细胞外信号调节激酶（extracellularsignal—regulatedkinase，ERK）通路影响P糖蛋白（P—glycoprotein，P—gP）的表达。方法应用RNA干扰技术和实时荧光定量PCR技术观察针对GCS的siRNA（GCSsiRNA）及ERK特异性化学抑制剂U0126分别作用于白血病耐药细胞株K562／A02细胞后，MDRlmRNA在不同情况下的表达情况；同时应用Western印迹法检测转染GCSsiRNA后细胞中ERK1／2（extracellarsignal—regulatedkinase1／2）蛋白的磷酸化及非磷酸化的变化，以及各组中P—gP的表达情况。结果与空白对照组比较，当ERK抑制剂U0126的浓度为10tLmol／L时，对磷酸化一ERK1／2（phosphorylated—ERK1／2，P—ERK1／2）无明显抑制，P—gP表达亦无明显差别；而随着U0126浓度的逐渐升高，达到20μmol／L、40μmol／L、60μmol／L时，对P—ERK1／2的抑制则呈浓度依赖性增强，同时P—gP的表达水平亦明显下调。RNA干扰实验显示：GCSsiRNA组的GCSmRNA表达被明显抑制，抑制率为70．50％（58．00％～76．00％）；与阴性干扰对照组比较，GCSsiRNA组在siRNA转染72h后P-ERK1／2的表达水平显著下调（P〈O．01），同时P-gp的表达亦明显下调（P〈O．05）。结论GCS可通过ERK1／2信号通路调控多药耐药蛋白P—gP的表达。Objective To investigate the effect of glucosylceramide synthase （GCS） on P-glycoprotein （P-gp） expression via extracellular signal-regulated kinase （ERK） pathways in leukemia K562/A02 cell line. Methods K562/A02 multidrug resistance cells were treated with GCSsiRNA and U0126, respectively. Expression of multidrug resistance protein 1 （MDR1） mRNA was analyzed with qRT-PCR. Phosphorylated ERK1/2, total ERK1/2 protein and P-gp in different groups were measured with Western blotting. Results After treated with U0126, P-ERK1/2 was decreased along with the increased U0126 concentration. P- ERK1/2 and P-gp were apparently down-regulated by U0126 at the concentrations of 20 μmol/L, 40 9mol/ L and 60 μmol/L. After being transfected with GCSsiRNA, GCSmRNA was inhibited by 70.50% （58.00% -76. 00%） in K562/A02 cells. Compared with the negative control, both P-ERK1/2 and P-gp were inhibited significantly after RNAi for 72 hours （P〈0.01 and P〈0.05, respectively）. Conclusion GCS may affect the expression of P-gp by ERK signal transduction pathway in leukemia cells.

关 键 词：葡萄糖神经酰胺合成酶 P-糖蛋白 ERK信号转导通路 白血病细胞 多药耐药 

分 类 号：R733.7[医药卫生—肿瘤]