EB病毒LMP1在鼻咽癌细胞系中通过TRAF2活化NF-kB  

Epstein-barr virus-encoded latent membrane protein 1 activates NF-ｋB via a mechanism involving TRAF2 in nasopharyngeal carcinoma

作　　者：王承兴[1] 李晓艳[1] 肖绘[1] 邓锡云[1] 曹亚[1] 

机构地区：[1]湖南医科大学肿瘤研究所,湖南长沙410078

出　　处：《癌症》2000年第6期517-520,共4页Chinese Journal of Cancer

基　　金：国家自然科学基金杰出青年基金!(39525022);美国中华医学基金!(CMB96655);国家自然科学基金!(3983041

摘　　要：目的：为了探讨ＥＢ病毒（ＥＢＶ）中ＬＭＰ１的致瘤机制，对鼻咽癌ＬＭＰ１激活重要的核转录因子ＮＦ－_ＫＢ的机制进行了研究。方法：①以ＬＭＰ１阴性的鼻咽癌细胞系ＨＮＥ２及表达载体（ｐＳＧ５）的鼻咽癌细胞系ＨＮＥ２－ｐＳＧＳ为对照，采用免疫共沉淀－Ｗｅｓｔｅｒｎ－ｂｌｏｔｔｉｎｇ方法在稳定表达ＬＭＰ１的鼻咽癌细胞系ＨＮＥ２－ＬＭＰ１中证实ＬＭＰ１与ＴＲＡＦ２是否直接结合形成免疫共沉淀复合物；②在ＨＮＥ２－ＬＭＰ１细胞系导入ＴＲＡＦ２表达质粒或不同剂量ＴＲＡＦ２显性负性突变体（ＴＲＡＦ２Ａ６－ ８６）表达质粒，以 ＮＦ－ｋＢ报道基因方法确定 ＬＭＰ1是否通过 ＴＲＡＦ2活化 ＮＦ－ｋＢ ；③将ＬＭＰ１（１－２３１）（ＣＴＡＲ２缺失区）或ＬＭＰ１△１８７－３５１（ＣＴＡＲＩ缺失区）及不同剂量ＴＲＡＦ２Ａ６－８６瞬时导入ＨＮＥ２中以证实ＬＭＰ１ ＣＴＡＲ１或ＣＴＡＲ２是否介导了这种效应；④以转染或未转染ＴＲＡＦ２６－８６的ＨＮＥ２－ＬＭＰ１细胞系为材料，应用免疫共沉淀－Ｗｅｓｔｅｒｎ－ｂｌｏｔｔｉｎｇ方法，确定ＴＲＡＦ２△６－８６是否竞争性抑制ＴＲＡＦ２与ＬＭＰ１结合。结果：①在ＨＮＥ２－ＬＭＰ１中ＬＭＰ１与ＴＲＡＦ２形成复合物?Objective: Our recent studies show the strong relationship between NF-ｋB activation mediated by LMP1 and nasopharyngeal carcinoma (NPC) neoplastic phenotype. We are trying to identify the mechanism involved. Methods: A stable transfectant cell line established by introducing LMP1 cDNA into HNE2 cells, HNE2-LMP1, was used as cell model. The association of LMP1 with TRAF2 was detected with immunoprecipitation-Western-blotting in the HNE2-LMP1; the role of TRAF2 in LMP1, LMP1 (1-231) or LMP1 A187-351-mediated NF-ｋB activation was evaluated using TRAF2 dominant negative mutant TRAF2△6-86 with reporter gene analysis; blocking of the association of TRAF2 with LMP1 by TRAF2△6~86 was investigated by immunoprecipitation-western blotting. Results: TRAF2 was bound and coprecipitated to LMP1 in an HNE2-LMP1 cell line. A dominant negative TRAF2 inhibits NF-ｋB activation from LMP1 and competes with TRAF2 for LMP1 binding. TRAF2△6-86 inhibits NF-ｋB activation mediated by LMPI (1-231) by more than 75% but inhibits NF-ｋB activation through LMP1△187-351 by less than 40%. Conclusion: These data implicate TRAF2 aggregation in NF-ｋB activation by LMP1 and provide an experimental basis for our study beginning from the signal transduction pathway for elucidation of the mechanism of LMP1 carcinogenesis.

关 键 词：鼻咽肿瘤 LMP1 TRAF2 NF-KB EB病毒 

分 类 号：R739.6[医药卫生—肿瘤]