Expressions of GFP in Tumor Cells under the Direction of HBV Promoters

Objective: To investigate the expression of GFP reporter gene under the direction of HBV promoters in tumor cells. Methods: GFP s65T and EⅡmCMV promoter(enhancer) of HBV were subcloned to mammalian expression vector pcDNA 3 by recombinant DNA technology. Three recombinant plasmids(pcDNA 3-GFP,pcDNA 3-GFP-EⅡ and pcDNA 3-GFP-EⅡ-w)were constructed. They were transfected into Hela and Bel7402 cells by Lipofectin and selected by G418 respectively, after amplification of the positive cell clones, they were used for fluorescence and Western blotting detection, GFP was quantitatively analysed by GEL Doc2000 digital image systems. Results: The correction of the recombinant plasmids was confirmed by restriction analysis and electrophorosis and positive cell clones were obtained through stable selection and GFP was within the value of background in parent and pcDNA 3 transfected Hela and Bel7402 cells and GFP protein of 27 kD existed in all GFP transfected cells. The expression of GFP was lower in Hela-GFP-EⅡ and Hela-GFP-EⅡ-w than that of Hela-GFP, but the expression of GFP in Bel-GFP-EⅡ-w was much higher than that of Hela-GFP-EⅡ-w. Conclusion: GFP reporter gene under the direction of HBV promoter(enhancer) could be expressed in tumor cells and be expressed definitely and specifically in HCC Bel7402 cell.