抑制MEK对内质网应激诱导乳腺癌细胞凋亡的增敏作用  

Inhibition of MEK sensitizes human breast carcinoma cells to endoplasmic reticulum pathway's apoptosis

作　　者：杨芬[1] 刘浩[1] 张旭东[1] 蒋志文[1] 

机构地区：[1]蚌埠医学院药学系药理学教研室,安徽蚌埠233030

出　　处：《中国药理学通报》2009年第6期778-782,共5页Chinese Pharmacological Bulletin

基　　金：安徽省人才开发资金资助项目(No2002Z023)

摘　　要：目的探讨抑制MEK/ERK信号通路对人乳腺癌细胞内质网(endoplasmic reticulum,ER)应激途径细胞凋亡的影响,以期为乳腺癌化疗提供新的靶点。方法不同浓度(0、1.5、3、6、9、12μmol.L-1)衣霉素(tunicamycin,TM)处理乳腺癌细胞SK-BR-3,48h后溴化丙啶(propidium iodide,PI)染色检测细胞凋亡率;TM(3μmol.L-1)处理SK-BR-3细胞不同时间(0、6、12、24、36h),Western blot检测葡萄糖调节蛋白78(glucose-regulated protein78,GRP78)、ERK1/2、pERK1/2的表达;MEK抑制剂U0126(20μmol.L-1)预处理1h后再给予TM(3μmol.L-1)同上处理,检测上述指标,比较U0126作用前后上述指标的变化。结果SK-BR-3细胞对TM诱导的细胞凋亡率<20%,且TM上调GRP78的表达;TM没有诱导ERK1/2的进一步激活;U0126明显增加TM诱导的细胞凋亡率(78%),同时下调GRP78的表达和阻断TM对GRP78的上调作用。结论MEK/ERK信号通路的抑制增强人乳腺癌细胞SK-BR-3对ER应激途径细胞凋亡的敏感性,抑制非折叠蛋白反应(unfolded protein response,UPR)的诱导。Aim To investigate the inhibition of MEK/ ERK pathway affecting the carcinoma cells SK-BR-3 sensitivity of human breast to endoplasmic reticulum （ER） stress-induced apoptosis and wish to find new targets for human breast carcinoma chemotherapy. Methods Different concentrations（0, 1.5, 3, 6, 9 and 12μmol·L^-1） tunicamycin（TM） treated human breast carcinoma cells SK-BR-3 for 48 h, then propidium iodide （PI） staining measured apoptotic cells in Flow Cytometry（FCM）. Different times（0, 6, 12, 24 and 36 h） of TM（3μmol·L^-1） treated SK-BR-3 cells, Western blot measured proteins GRP78, ERK1/ 2 and pERK expression. MEK inhibitor U0126 （20μmol·L^-1） pretreated cells for 1 h before treatment with TM （3μmol·L^-1） in different concentrations and times, measured above identical indexes and compared with their diversities of treatment with U0126 or not. Results TM induced apoptotic cells 〈 20% and TM markedly up-regulated GRP78 expression. Combination of U0126 and TM induced apoptotic cells to 78%. TM did not induce further activation of ERK1/2 in SK-BR-3 cells. U0126 down-regulated GRP78 expression and blocked TM-induced up-regulation of GRP78. Conclusion U0126 sensitizes human breast carcinoma cells SK-BR-3 to ER stress-induced apoptosis. U0126 inhibits TM-induced unfolded protein response （UPR）.

关 键 词：乳腺癌 ER应激 GRP78 细胞凋亡 MEK抑制 

分 类 号：R329.25[医药卫生—人体解剖和组织胚胎学]