鼻咽癌中EB病毒LMP1激活TRAFs的初步研究

在EB病毒潜伏膜蛋白LMP1介导的信号传导通路中，TRAFs作为LMP1活化的第一位信号分子，可能扮演着重要的分子开关角色。令人关注的是，在上皮性肿瘤NPC的发生中，EB病毒LMP1能否激活重要的TRAFs信号分子?究竟激活何种TRAFs信号分子，激活的机制何在?将LMP1cDNA导入LMP1表达阴性的HNE2中，建立稳定表达LMP1的鼻咽癌细胞系HNE2-LMP1。以此为材料，应用差异RT-PCR和Western blotting法证实，无论在RNA水平，还是蛋白水平上，TRAF1在HNE2-LMP1中表达较HNE2强，而TRAF2及TRAF3在HNE2-LMP1与HNE2细胞中表达无明显差异；进一步用免疫共沉淀-Western blotting证实LMP1可使TRAF1、TRAF2、TRAF3磷酸化而被活化。这些结果提示在鼻咽癌中，LMP1可能诱导TRAF1表达，而对TRAF2及TRAF3并不影响，但LMP1可磷酸化TRAF1、TRAF2、TRAF3而使其功能性活化。q

Preliminary Study on the Activation of TRAFs Mediated by Epstein-Barr Virus Encoded LMP1 in Nasopharyngeal Carcinoma

The present is aimed at identifying the activation of TRAFs in n asopharyngeal carcinoma (NPC) in vitro. The differential expression of TRAF2\,TRAF3 was not detected in RN A and protein level, whereas the expression of TRAF1 in HNE2-LMP1 cell lines wa s much more abundant than that in HNE2 cell lines, suggesting that TRAF1 may be an inducible molecule; More importantly, TRAF1, TRAF2 or TRAF3 were activated in the HNE2-LMP1 cells, whereas TRAF1, TRAF2 or TRAF3 were not activated in HNE2 cells as detected by the immunoprecipitation-Western blotting assay. These data provide an experimental basis for our study beginning from the signal transduca tion pathway for the eluccidation of the mechanism of LMP1 carcinogenesis in NP C.