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为了探讨EB病毒潜伏膜蛋白 1(LMP1)的致瘤机制 ,对鼻咽癌中LMP1激活重要的核转录因子NF κB机制进行了研究 .首先 ,采用免疫共沉淀 蛋白质印迹在稳定表达LMP1的鼻咽癌细胞系HNE2 LMP1中证实LMP1与TRAF1,2 ,3结合形成免疫共沉淀复合物 ,进一步以野生型LMP1及其三种突变体的鼻咽癌细胞系LMP1(野生型 ,wt)、HNE2 LMP1del187～ 35 1(CTAR1缺失型 )、HNE2 LMP1(1～ 2 31) (CTAR2缺失型 )、HNE2 LMP1(1～ 187) (羧基端胞浆区缺失型 )、HNE2 pSG5 (空白载体型 )为材料 ,结合NF κB报道基因质粒(pGL2 NF κB luc)的荧光素酶活性表达分析NF κB的活性 ,证实 :较之母细胞 ,野生型LMP1活化NF κB达13 8倍 ,LMP1(1～ 187)几乎不活化NF κB ,LMP1(1～ 2 31)活化NF κB达 4 9倍 ,LMP1(del187～ 35 1)活化NF κB达 9 1倍 ;TRAF1过表达升高LMP1(wt)及LMP1(1～ 2 31)介导的NF κB活性 ,而对LMP1(del187～ 35 1)活化NF κB无影响 ;TRAF3过表达或TRAF3负显性突变体抑制LMP1(wt)及LMP1(1～ 2 31)介导的NF κB活性 ,而不影响LMP1(del 187～ 35 1)活化NF κB ;TRAF2过表达升高LMP1(wt)、LMP1(1～2 31)及LMP1(del 187～ 35 1)介导的NF κB活性 .这些结果表明 :鼻咽癌中LMP1通过TRAF1、TRAF2或TRAF3调控NF κB ,TRAF1和TR
To investigate the tumorigenic mechanism of Epstein-Barr virus latent membrane protein 1 (LMP1), an important nuclear transcription factor NF κB mechanism of LMP1 activation in nasopharyngeal carcinoma was studied. First, immunoco-precipitation western blot was used to stably express LMP1 in the nasopharyngeal In the cancer cell line HNE2 LMP1, it was confirmed that LMP1 binds to TRAF1, 2, 3 to form an immunoprecipitated complex, and further to wild-type LMP1 and its three mutant nasopharyngeal carcinoma cell lines LMP1 (wild-type, wt), HNE2 LMP1del187- 35 1 (CTAR1 deletion type), HNE2 LMP1 (1 to 2 31) (CTAR2 deletion type), HNE2 LMP1 (1 to 187) (carboxyl-terminal cytoplasmic deletion type), and HNE2 pSG5 (blank vector type) as materials, binding The activity of NF-κB was analyzed by luciferase activity expression of NF κB reporter plasmid (pGL2 NF κB luc). It was confirmed that wild-type LMP1 activated NF κB up to 13 8 times compared to blast cells, and LMP1 (1 to 187) was almost inactivated. NF κB and LMP1 (1～2 31) activated NFκB 4 9-fold, LMP 1 (del187～ 35 1) activated NF κB 9 1 times; TRAF 1 overexpression increased LMP 1 (wt) and LMP 1 (1-231) Mediated NF κB activity but no effect on LMP1 (del187～ 35 1) activation of NF κB; TRAF3 overexpression or TRAF3 negative overexpression Inhibits LMP1 (wt) and LMP1 (1 to 2 31)-mediated NF κB activity without affecting LMP1 (del 187-35 1) activation of NF κB; TRAF2 overexpression increases LMP1 (wt), LMP1 (1～ 2 31) and LMP1 (del 187-351) mediated NF κB activity. These results indicate that LMP1 regulates NFκB, TRAF1, and TR through TRAF1, TRAF2, or TRAF3 in nasopharyngeal carcinoma.