[Mechanism of migration in CNE2 cells promoted by EBV-LMP1].

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-LMP1(TRADD) 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-LMP1(TRADD), 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 epithelial 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 microg). LMP1(TRADD) 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 that EBV-LMP1 suppresses the transcriptional activity of E-Cadherin promoter. TRADD of carboxyl terminus of LMP1 may be the main active domain to promote the migration in NPC cells.