Expression of Epsteinª²Barr virus RPMS1 gene in nasopharyngealcarcinoma and its subcellular location in vitro

    LI Ang, ZHANG Xiaoª²Shi, WANG Jiaª²Xiang, ZHAO Song, ZHAO Gaoª²Feng, HU Wei, QIN Jianª²Jun, YIN Deª²Tao

    1Department of Thoracic Surgery, 3Department of Surgery, First Hospital, Zhengzhou University, Zhengzhou 450052, China, 2Institute of Cancer Center, Sun Yatª²sen University, Guangzhou 510060, China

    ¡¾Abstract¡¿ AIM: To investigate the expression of RPMS1 mRNA in biopsies of nasopharyngeal carcinoma (NPC) in the area with high incidence and to observe the subcellular fraction of its encoding protein. METHODS: DNA and total RNA were isolated from tissues and cells. Nested PCR was designed to amplify the W sequence of EBV DNA and RTª²PCR was used to analyze the transcription of RPMS1 in all samples. RPMS1 coding sequence (CDS) amplified from NPC tissues was cloned into pEGFPª²C2. After transfected with this recombinant plasmid by lipofectin mediation, HEK293 cells were analyzed by RTª²PCR and laser confocal microscope to observe the expression of RPMS1 and its subcellular fraction. RESULTS: Except for BJAB cells, EBV W sequence was observed in all the samples. RPMS1 expressed in 83.3%(45/54) NPC biopsies and 4%(1/25)noncarcinoma nasopharynx biopsies with significant difference between them but no RPMS1 mRNA was detected in peripheral lymphocytes of NPC. RPMS1 expressed at lower level in Raji than in SUNE1 and was not expressed in B95.8 cells. The recombinant plasmid was constructed and expressed stably in HEK293 cells, in which the fusion protein was found to be nuclear. CONCLUSION: EBVª²RPMS1 gene is expressed in NPC tissues in the area with high incidence and its encoding protein can stably express in cytoplasm of epithelial cell in vitro, suggesting that RPMS1 may function as a nuclear transcriptional factor by regulating the signal conduction related with cellular proliferation. ......