Wang Chengxing, Ai Midan, Ren Wei, Xiao Hui, Li Xiaoyan, Tang Faqing, Gu Huanhua, Yi Wei, Weng Xinxian, Deng Xiyun, Cao Ya
Department of Oral and Maxillofacial Surgery, Xiang Ya Hospital, Central Southern University, Changsha 410078, China.
Chin Med J (Engl). 2003 Jul;116(7):1022-8.
To identify whether Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) can induce tumor necrosis factor receptor-associated factor 1 (TRAF1) expression and promote its anti-apoptosis activity via the NF-kappaB signaling pathway, and assess that LMP1 suppresses apoptosis in nasopharyngeal carcinoma (NPC).
A stable transfected cell line HNE2-LMP1 was established by introducing LMP1 cDNA into HNE2 cells. Transactivation of TRAF1 was determined by luciferase reporter assay, while expression of TRAF1 mRNA was detected by RT-PCR and expression of TRAF1 protein and caspase 3 by Western blot analysis. Apoptosis activity was observed through fluorescence staining.
LMP1 induced TRAF1 expression in NPC cells and caused a decrease in apoptosis. This induction could be blocked by antisense LMP1. Moreover, LMP1-mediated induction of a TRAF1 promoter-driven reporter gene was significantly impaired when the kappaB site kappaB1 or kappaB5 was disrupted, whereas mutation of kappaB3 had only a minor effect on LMP1 dependent up-regulation of the reporter gene.
LMP1 induces TRAF1 expression and promotes its anti-apoptosis activity via the NF-kappaB signaling pathway, which may be one of the mechanisms that LMP1 uses to suppress apoptosis in NPC cells.
确定爱泼斯坦-巴尔病毒（EBV）编码的潜伏膜蛋白1（LMP1）是否能通过核因子κB（NF-κB）信号通路诱导肿瘤坏死因子受体相关因子1（TRAF1）表达并促进其抗凋亡活性，并评估LMP1对鼻咽癌（NPC）细胞凋亡的抑制作用。
将LMP1 cDNA导入HNE2细胞，建立稳定转染细胞系HNE2-LMP1。通过荧光素酶报告基因检测确定TRAF1的反式激活，通过逆转录-聚合酶链反应（RT-PCR）检测TRAF1 mRNA的表达，通过蛋白质免疫印迹分析检测TRAF1蛋白和半胱天冬酶3的表达。通过荧光染色观察细胞凋亡活性。
LMP1诱导NPC细胞中TRAF1表达并导致细胞凋亡减少。反义LMP1可阻断这种诱导作用。此外，当κB位点κB1或κB5被破坏时，LMP1介导的TRAF1启动子驱动的报告基因诱导明显受损，而κB3突变对LMP1依赖的报告基因上调只有轻微影响。
LMP1通过NF-κB信号通路诱导TRAF1表达并促进其抗凋亡活性，这可能是LMP1抑制NPC细胞凋亡的机制之一。
