1. ¹Cancer Research Institute, Xiangya School of Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan 410078, China
2. ²Molecular Medical Center, Tongji Hospital, Tongji Medical University, Wuhan 430030, China

Correspondence: Ya CAO, Tel: +86-731-4805448; Fax: +86-731-4470589; E-mail: ycao98@public.cs.hn.cn

Received 12 September 2005; Revised 26 September 2005; Accepted 15 October 2005.

Abstract

Latent membrane protein 1 (LMP1), an important protein encoded by Epstein Barr virus (EBV), has been implied to link with the pathogenesis of nasopharyngeal carcinoma (NPC). Its dual effects of increasing cell proliferation and inhibiting cell apoptosis have been confirmed. In this study, we showed that the expression of Survivin and CDK4 protein in CNE-LMP1, a LMP1 positive NPC epithelial cell line, is higher than in LMP1 negative NPC epithelial cell line-CNE1, and the expression is LMP1 dosage-dependent. Although it was reported that Survivin specifically expressed in cell cycle G₂/M phase, our studies suggested that LMP1 could promote the expression of Survivin in G₀/G₁, S and G₂/M phase. It also showed that Survivin and CDK4 could be accumulated more in the nuclei triggered by LMP1. More interestingly, Survivin and CDK4 could form a protein complex in the nuclei of CNE-LMP1 rather than in that of CNE1, which demonstrated that the interaction between these two proteins could be promoted by LMP1. These results strongly suggested that the role of LMP1 in the regulation of Survivin and CDK4 may also shed some light on the mechanism research of LMP1 in NPC.