[Effect of Epstein-Barr virus latent membrane protein 1 (LMP1) on apoptosis of nasopharyngeal carcinoma cell line CNE1].

BACKGROUND & OBJECTIVE: It was proved that Epstein-Brarr virus (EBV) latent membrane protein 1 (EBV-LMP1) has transformation function which plays an important role in the genesis and development of nasopharyngeal carcinoma (NPC) and this function may be associated with apoptosis. This study was designed to investigate the effect of EBV-LMP1 on apoptosis of NPC CNE1 cell line and to explore the possible mechanism of the function of EBV-LMP1 in the genesis and development of NPC.

METHODS

The authors transfected LMP1 eukaryotic expression plasmid carried with the green fluorescent protein (GFP) reporter gene into CNE1 cell line by electroporation. The expression of GFP was detected by fluorescent microscope; the expression of aimed gene LMP1 was detected by immunohistochemistry and Western blot; the effect of LMP1 on apoptosis of CNE1 cells which were treated either with dexamethasone sodium phosphate or serum starvation was investigated by flow cytometry analysis, fluorescence staining, and DNA fragmentation analysis.

RESULTS

The green fluorescence could be detected in CNE1G cells transfected by control plasmid PAT-GFP and in CNE1GL cells transfected by plasmid PAT-GFP-LMP1, while there was no GFP expression in CNE1 cells untransfected by any plasmid. LMP1 could be detected in CNE1CL cells, but not in CNE1 and CNE1C cells. Apoptosis could be observed in three groups cells which were treated either with dexamethasone sodium phosphate or serum starvation, and the apoptosis index (AI) of CNE1CL cells was higher than that in CNE1 and CNE1G cells (P < 0.05). There were no apoptosis occurring in three group cells when cultured in regular medium.

CONCLUSIONS

The LMP1 gene was transfected successfully into CNE1 cells which were stably expressing LMP1. LMP1 could increase apoptosis occurring of CNE1 cells in the process of inducing apoptosis.