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为了探讨在鼻咽癌细胞中EB病毒编码的潜伏膜蛋白 1(LMP1)激活c Jun氨基端激酶 (JNK)信号途径的分子机制 ,利用可调控表达LMP1的鼻咽癌细胞系L7,蛋白质印迹检测 ,发现LMP1能够促进JNK的活化 ;利用稳定表达LMP1的鼻咽癌细胞系HNE2 LMP1及其三种突变体HNE2 LMP1ΔCTAR 1、HNE2 LMP1ΔCTAR2、HNE2 LMP1ΔCTAR 1,2及LMP1阴性的HNE2 为材料 ,采用蛋白质印迹和报告基因法分析JNK和活化蛋白 1(AP1)活化情况 ,结果显示HNE2 LMP1和HNE2 LMP1ΔCTAR1中磷酸化JNK蛋白表达量和AP1活性都无显著差异 ,而与HNE2 LMP1ΔCTAR2、HNE2 LMP1ΔCTAR1,2、阴性对照HNE2及空白载体转染细胞的JNK蛋白表达和AP1活性具有显著差异 ;进一步比较转染TRAF、TRADD显性负性突变体鼻咽癌细胞系HNE2 LMP1中磷酸化的JNK量和AP1活性 ,结果显示 :TRAF DN和TRADD DN的导入使活化的JNK蛋白和AP 1活性显著降低 ,二者间无显著差异 ,提示TRAF和TRADD可能参与了LMP1对JNK和AP 1的活化 .以上结果提示在鼻咽癌细胞系中LMP1功能结构域CTAR2通过结合TRAF/TRADD激活JNK从而活化重要的转录因子AP1.
In order to explore the molecular mechanism of Epstein-Barr virus encoded latent membrane protein 1 (LMP1) activating c-Jun N-terminal kinase (JNK) signaling pathway in nasopharyngeal carcinoma cells, nasopharyngeal carcinoma cell line L7, which can regulate the expression of LMP1, , And found that LMP1 can promote the activation of JNK; HNE2 LMP1 cell line stably expressing LMP1 and its three mutants HNE2 LMP1ΔCTAR 1, HNE2 LMP1ΔCTAR2, HNE2 LMP1ΔCTAR 1,2 and LMP1 negative HNE2 as material, using Western blot And reporter gene analysis of activation of JNK and AP1, the results showed no significant difference in the expression of phosphorylated JNK protein and AP1 activity between HNE2 LMP1 and HNE2 LMP1ΔCTAR1, but not with HNE2 LMP1ΔCTAR2, HNE2 LMP1ΔCTAR1,2, negative control HNE2 and blank vector transfected JNK protein expression and AP1 activity was significantly different; further TRAF, TRADD dominant negative mutant nasopharyngeal carcinoma cell line HNE2 LMP1 phosphorylation of JNK amount and activity of AP1, the results showed : The introduction of TRAF DN and TRADD DN significantly reduced the activity of activated JNK protein and AP 1, with no significant difference between them, suggesting that TRAF and TRADD may be involved LMP1 activates JNK and AP 1. The above results suggest that the LMP1 functional domain CTAR2 activates the important transcription factor AP1 by activating JNK in combination with TRAF / TRADD in nasopharyngeal carcinoma cell lines.