RESUMO
BACKGROUND & OBJECTIVE: Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) plays an important role in the metastasis of nasopharyngeal carcinoma (NPC). This study was to investigate the effects of EBV LMP1 on the metastasis of NPC cell lines, and explore potential mechanism. METHODS: The expression of LMP1, E-cadherin and intercellular adhesion molecule-1 (ICAM-1) in human NPC cell lines CNE1 (well differentiated) and CNE1-GL (CNE1 cells transfected with LMP1) were detected by SP immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The cell-cell adhesion assay, the cell-matrix adhesion assay, the wound-induced migration assay and the migration assay were used to investigate the effects of LMP1 on adhesive and metastatic abilities of NPC cells. RESULTS: The positive rates of LMP1 and ICAM-1 were significantly lower in CNE1 cells than in CNE1-GL cells [0% vs. (96.60+/-3.03)%, P<0.01; (5.27+/-1.45)% vs. (93.33+/-4.23)%, P<0.01]; the positive rate of E-cadherin was significantly higher in CNE1 cells than in CNE1-GL cells [(37.47+/-1.50)% vs. (19.53+/-1.92)%, P<0.01]. The expression of E-cadherin was significantly inhibited (P<0.01), while the expression of ICAM-1 was significantly increased (P<0.01) in CNE1-GL cells as compared with those in CNE1 cells. The cell-cell adhesive ability of CNE1-GL cells was lower than that of CNE1 cells (P<0.05). The cell-matrix adhesive ability of CNE1-GL cells was significantly higher than that of CNE1 cells (0.60+/-0.03 vs. 0.46+/-0.01, P<0.01). The number of migrated CNE1-GL cells was higher than that of migrated CNE1 cells (119.3+/-6.0 vs. 46.3+/-7.0, P<0.05). CONCLUSION: By inhibiting E-cadherin expression and enhancing ICAM-1 expression, LMP1 may reduce the cell-cell adhesive ability and improve the cell-matrix adhesive ability and migratory ability of NPC cells, which may play roles in the invasion and metastasis of NPC.
