BAG-1蛋白在衣霉素诱导人肺癌A549细胞内质网应激及提高顺铂敏感性中的作用  

The role of BAG-1 in endoplasmic reticulum stress and the enhancement of cisplatin sensitivity in A549 lung cancer cells induced by tunicamycin

作　　者：刘京松[1] 王亚帝[2] 李岩欣[1] 哈敏文[3] 刘志良[1] 

机构地区：[1]辽宁医学院附属第一医院胸外科,锦州121001 [2]辽宁医学院附属第三医院肿瘤科,锦州121001 [3]辽宁医学院附属第一医院肿瘤科,锦州121001

出　　处：《肿瘤》2012年第2期99-104,共6页Tumor

基　　金：辽宁省教育厅科研项目计划(编号:L2010286)

摘　　要：目的:体外观察低剂量衣霉素对人肺腺癌A549细胞内质网应激(endoplasmi creticulum stress,ERS)的诱导作用,以及此过程中Bcl-2结合抗凋亡基因1(Bcl-2associated athanogene 1,BAG-1)表达的变化;同时,观察衣霉素作用后A549细胞对顺铂敏感性的变化以及此过程中BAG-1蛋白表达的变化。方法:采用蛋白质印迹法检测低剂量衣霉素作用A549细胞后ERS标志性蛋白GRP78及抗凋亡蛋白BAG-1的表达变化;MTT法测定衣霉素作用后顺铂对A549细胞的半数抑制浓度(halfinhibitory concentration,IC50)变化;FCM法检测低剂量衣霉素作用后A549细胞对顺铂的敏感性变化;蛋白质印迹法检测衣霉素作用前后顺铂对A549细胞中BAG-1和procaspase-12蛋白表达的影响。结果:1.25μg/mL衣霉素作用A549细胞8h后,能诱导细胞发生ERS,即ERS标志性蛋白GRP78表达上调,同时BAG-1蛋白表达也明显上调(P均<0.05)。衣霉素诱导A549细胞ERS能增加细胞对顺铂的敏感性(P<0.05)。细胞发生ERS前,1.25、2.5和5μg/mL3个质量浓度的顺铂均上调BAG-1蛋白的表达(P均<0.05),但2.5和5μg/mL顺铂诱导BAG-1蛋白上调量均小于1.25μg/mL组(P<0.05);细胞发生ERS后,与单纯ERS未给予顺铂干预的细胞组比,1.25、2.5和5μg/mL3个质量浓度的顺铂均下调BAG-1蛋白的表达(P均<0.05),且下调量与顺铂浓度呈正比。2.5和5μg/mL顺铂能通过ERS途径诱导细胞发生凋亡,在此过程中BAG-1和procaspase-12蛋白表达均下调(P均<0.05)。结论:BAG-1蛋白可能是ERS和顺铂诱导肺癌细胞凋亡的一个重要调控因子之一,且ERS凋亡途径可能是顺铂诱导肺癌细胞凋亡的重要途径之一。Objective：To observe the induced effect of low dose of tunicamycin on endoplasmic reticulum stress（ERS） of A549 human lung adenocarcinoma cells in vitro and the change of Bcl-2 associated athanogene 1（BAG-1） protein expression,as well as the changes of cisplatin（DDP） sensitivity and the BAG-1 protein expression.Methods：The expressions of GRP78（a marker protein in ERS） and BAG-1 proteins in A549 cells treated with low dose of tunicamycin were detected by Western blotting.The change of half inhibitory concentration（IC50） of DDP for A549 cells after pretreatment with tunicamycin was measured by MTT method,and the DDP sensitivity was determined by flow cytometry（FCM）.The Western blotting was carried out to detect the expressions of BAG-1 and procaspase-12 proteins in A549 cells induced by DDP after pretreatment with tunicamycin.Results：The ERS in A549 cells could be induced by pretreatment with 1.25 μg/mL tunicamycin for 8 h,which displayed that the expression levels of GRP78 and BAG-1 proteins were both up-regulated（P0.05）.The ERS could increase the DDP sensitivity in the A549 cells（P0.05）.Before ERS occurred,all of three doses of DDP（1.25,2.5 and 5 μg/mL） could up-regulate the expression level of BAG-1 protein（P0.05）,and this effect was more obvious in 1.25 μg/mL DDP-treated A549 cells.When ERS occurred,the expression levels of BAG-1 protein in all of three doses of DDP（1.25,2.5 and 5 μg/mL）-treated A549 cells were down-regulated in a dose-dependent manner as compared with that in the A549 cells without DDP treatment（P0.05）.The DDP dose of 2.5 and 5 μg/mL could induce apoptosis by ERS pathway,and the expression levels of BAG-1 and procaspase-12 proteins were both down-regulated during this process（P0.05）.Conclusion：BAG-1 may be one of the important regulatory factors in both pathways of ERS-and cisplatin-induced apoptosis of lung cancer cells,and ERS-related apoptotic pathway may be one of the important pathways of cisplatin-induced apoptosis of lung

关 键 词：肺肿瘤 衣霉素 顺铂 细胞凋亡 Bcl-2相关凋亡素 内质网应激 BAG-1蛋白 

分 类 号：R734.2[医药卫生—肿瘤]