热休克蛋白90通过抑制Bid裂解抑制NIH3T3成纤维细胞凋亡  

Heat shock protein90 suppressing apoptosis by preventing the cleavage of Bid in NIH3T3 fibroblasts

作　　者：齐凤杰[1] 王妍[1] 张秀伟[1] 徐洪涛[1] 戴顺东[1] 王恩华[1] 

机构地区：[1]中国医科大学基础医学院病理教研室,辽宁沈阳110001

出　　处：《中华肿瘤防治杂志》2006年第11期804-808,共5页Chinese Journal of Cancer Prevention and Treatment

基　　金：国家自然基金资助项目(30470764)

摘　　要：目的探讨热休克蛋白90(heatshockproteins90,HSP90)抑制肿瘤坏死因子α(tumornecrosisfactorα,TNFα)和放线菌酮(cycloheximide,CHX)诱导的细胞凋亡作用机制。方法采用电穿孔技术建立稳定过表达HSP90的细胞克隆;应用激光共聚焦显微镜和流式细胞仪,观察TNFα/CHX诱导的细胞凋亡及HSP90对细胞凋亡的拮抗作用;应用Westernblotting及免疫沉淀方法,检测HSP90是否直接作用于Bid(BH3interactingdeathag-onist)及HSP90抑制剂格尔德霉素的功能。结果在稳定过表达HSP90的NIH3T3细胞中,HSP90能够抑制TNF-α/CHX诱导的细胞凋亡;HSP90通过直接与Bid结合阻止Bid的裂解来抑制TNF-α/CHX诱导的细胞凋亡;HSP90的特异性抑制剂格尔德霉素可以拮抗HSP90,阻止Bid裂解。结论HSP90的大量存在(即使在生理条件下)不仅通过促进蛋白质的折叠,而且通过阻止Bid的裂解而保持前凋亡因子的惰性状态,使细胞免于凋亡,对细胞稳态的维持发挥重要作用;HSP90抑制剂作为抗肿瘤药物的一个作用机制,可能通过促进Bid从HSP90复合物中释放,进而促进肿瘤细胞凋亡。OBJECTIVE： To investigate the underlying mechanism of HSP90 suppressing tumor necrosis factor α （TNFα） and cycloheximide（CHX）-induced apoptosis. METHODS： We used electroporation to establish stable HSP90 overexpression clones; using laser confocal microscopy and flowcytometry to observe apoptosis induced by TNF-α/CHX; using Western blotting and immunoprecipitation to show whether HSP90 binds directly with Bid（BH3 interacting death agonist） and monitor the changes of Bid and the function of HSP90＇s inhibitor geldanamycin in this event. RESULTS： HSP90 suppressed TNFα/ CHX-induced apoptosis in stable HSP90-overexpressing NIH3T3 cells; The mechanism by which HSP90 suppressed TNFα-induced apoptosis was that HSP90 prevented the cleavage of Bid through direct binding with Bid; disrupting the function of HSP90 by the addition of its specific inhibitor, geldanamycin, blocked HSP90＇s protection of Bid cleavage. CONCLUSION： The abundant existence of HSP90, even in physiological conditions, plays an important role in preventing cell apoptosis and maintaining cellular homeostasis, not only by promoting protein folding, but also by preventing Bid cleavag and keeping proapoptotic factors in an inert state; one mechanism by which HSP90＇s inhibitor acts as an anti-cancer drug could be to promote the release of Bid from the HSP90 complex, and this event promotes cancer cell apoptosis.

关 键 词：热休克蛋白质90 肿瘤坏死因子 放线菌酮 

分 类 号：R73-3[医药卫生—肿瘤]