中文摘要：

目的：探讨EBV-LMP1对鼻咽癌细胞CNE2迁移表型的影响及作用机制。方法：用RV-LNSX，RV-LMP1和RV-LMP1^TRADD。逆转录病毒分别感染CNE2细胞，G418筛选后，观察和检测转基因细胞的形态学特点，在基质中的运动迁移能力以及R-钙黏蛋白（E-Cadherin）表达的变化；用pLNSX，pLNSX-LMP1和pLNSX—LMPI^TRADD质粒分别与E-Cadherin报告基因共转染293细胞，检测LMP1对E-Cadherin启动子活性的影响。结果：与CNE2和CNE2-LNSX细胞相比，CNE2-LMP1在培养过程中由扁平、鹅卵状上皮细胞形态逐渐演变为细胞间接触消失的长梭状纤维细胞形态，相对迁移明显增大（n=3，P〈0.05）。且E-Cadherin表达明显下调或缺失；随着共转染野生型LMP1（pLNSX-LMP1）剂量的增加（0．2，0、6，1．0μg），对E／-Cadherin启动子转录活化的抑制率增加，呈明显浓度依赖性；LMPI^TRADD不改变CNE2细胞形态学及迁移表型，对E-Cadherin启动子的转录活性及蛋白表达亦无明显影响。结论：抑制E-Cadherin启动子活化可能是EBV-LMP1下调E-Cadherin蛋白表达、促CNE2细胞迁移的机制之一，位于LMP1羧基端的TRADD可能是其促迁移的主要活性部位。

英文摘要：

Objective To investigate the mechanism of migration phenotype change induced by EBV-LMP1 in nasopharyngeal carcinoma （NPC） cell line CNE2. Methods Retroviruses RV-LNSX, RV-LMP1 , and RV-LMP1TRADD prepared previously were used to infect CNE2 cells. After selection with G418, the morphology, the ability of motion and migration in extracellular matrix, expression of LMP1 and E-Cadherin in transgenic cells were observed or detected. Meanwhile, pEcad-luc was respectively co-transfected with pLNSX, pLNSX-LMP1 , and pLNSX-LMP1TRADD, to examine the effect of LMP1 on the transcriptional activity of E-Cadherin promoter in 293 cells. Results Compared with CNE2 and CNE2-LNSX cells, CNE2-LMP1 cells morphologically changed from typical ep- ithelial appearance to long-spindle fibroblastic morphology with the concomitant loss of cell-to-cell contact, and relative migration of CNE2-LMP1 cells obviously increased （n =3, P 〈0.05）, while the expression of E-Cadherin was negative in CNE2-LMP1 cells. The transcriptional activity of E- Cadherin promoter and the expression of E-Cadherin was suppressed by LMP1 , and the level of suppression was correlated with the concentration of pLNSX-LMP1 （0.2,0.6 and 1.0 μg）. LMP1TRADD didn＇t induce the changes of morphology and migration phenotype, nor suppress the transcriptional activity of E-Cadherin promoter and the expression of E-Cadherin in CNE2 cells. Conclusion EBV-LMP1 promotes the migration and down-regulates the expression of E-Cadherin in CNE2 cells.The mechanism is TRADD of carboxyl NPC cells. that EBV-LMP1 suppresses terminus of LMP1 may be the transcriptional activity the main active domain to of E-Cadherin promoter. promote the migration in