Regulation Of The Effect Of Hepatitis B Virus On DNAJB4 Transcriptional Level Expression In Vitro

ObjectiveTo explore the relationship between HBV and transcriptional level expression of DNAJB4 in vitro, to reveal new mechanisms of HBV-induced hepatocellular carcinoma, to provide new ideas for the treatment of HBV infection and new knowledge for in-depth understanding of the transcriptional regulation of DNAJB4.Methods1. RT-PCR and Real-time PCR were performed to detect DNAJB4 expression on mRNA level in HepG2 and HepG2.2.15 cell lines.2. DNAJB4 promoter luciferase reporter plasmid, pGL3-Basic-DNAJB4-P, was constructed. HepG2 cells were transiently cotransfected with the same amount of pGL3-Basic-DNAJB4-P and HBV expression plasmids or control plasmids, respectively. Then their luciferase activities were detected.3. HBs, HBp, HBc and HBx expression plasmids were constructed. HepG2 cells were transiently cotransfected with the same amount of pGL3-Basic-DNAJB4-P and HBx or HBs or HBc or HBp expression plasmids, respectively. Then their luciferase activities were detected.Results1. RT-PCR results showed that the amount of DNAJB4 expression on mRNA level in HepG2.2.15 cells is 3 times higher than that in HepG2 cells. Real-time PCR showed that the amount of DNAJB4 expression on mRNA level in HepG2.2.15 cells is 2.59 times higher than that in HepG2 cells. 2. DNAJB4 promoter luciferase reporter plasmid, pGL3-Basic-DNAJB4-P, was successfully constructed. The relative luciferase activity in HepG2 cells, which were transiently cotransfected with pGL3-Basic-DNAJB4-P and HBV expression plasmid, is 2.28 times higher than that in control group.3. The relative luciferase activities in HepG2 cells transfected with HBs or HBc expression plasmids are 2.11 times and 1.77 times higher than those in control group, respectively. However, HBx and HBp expression plasmids had no effect on luciferase activity.ConclusionWe found that HBV upregulates DNAJB4 transcriptional level expression in HepG2.2.15 cells through enhancing its promoter activity, and HBs, HBc proteins may play important roles in enhancing DNAJB4 promoter activity. This study can provide new knowledge for in-depth understanding of the transcriptional regulation mechanism of DNAJB4 and new insights for HBV-induced hepatocellular carcinoma.