Objective: To study the promoter activity in HepG2 cells of the DNA sequence corresponding to the HCV 5'UTR.
Methods: Plasmids, 5'UTR-Luc(+) and 5'UTR-Luc(-) carrying the forward and reverse DNA sequences corresponding to the HCV 5'UTR respectively were constructed, and subsequently transfected into HepaG2 cells. The luciferase activity and the mRNA of the luciferase gene were then detected. The 5'UTR sequence was cloned into a GFP vector to make 5'UTR-EGFP, and then the GFP expression was confirmed by fluorescence microscopy.
Results: 5'UTR-Luc(+) had an obvious luciferase activity whereas 5'UTR-Luc(-) had nearly no luciferase activity. The former had a high level of luciferase mRNA while the latter could not be detected. An intense green fluorescence expression was observed in the cells transfected with the plasmid of 5'UTR-EGFP.
Conclusion: The forward DNA sequence corresponding to HCV 5'-UTR had an obvious promoter activity in hepG2 cells. It may play an important role in the replication of HCV.