Transcriptional inhibitory effect of hepatitis B virus X protein on the expression of p53 tumor suppression gene / 中华实验和临床病毒学杂志

ABSTRACT

<p><b>BACKGROUND</b>To investigate the transcriptional inhibitory role of hepatitis B virus X protein on the expression of p53 tumor suppression gene.</p><p><b>METHODS</b>The promoter sequence of the p53 tumor suppression gene was identified and amplified by bioinformatics and polymerase chain reaction (PCR). The recombinant reporter gene expression vector pCAT3-p53p was constructed and transfected into the hepatoblastoma cell line HepG2 and cotransfected with pcDNA3.1 (-)-X by Fugene 6 transfection reagents. The chloramphenicol acetyl transferase (CAT) activity was detected by enzyme-linked immunosorbent assay (ELISA). The expression of p53 mRNA was further detected by RT-PCR with or without HBV X protein.</p><p><b>RESULTS</b>The reporter vector pCAT3-p53p has been successfully constructed and identified and the p53 promoter could cis-activate the transcription of the CAT gene. The relative expression level of CAT gene in HepG2 cells cotransfected with pCAT3-p53p and pcDNA3.1 (-)-X was lower than the control, and the inhibitory rate was approximately 78%, which indicate that HBV X protein could transcriptionally inhibit the activity of p53 promoter. After transfected with pcDNA3.1 (-)-X, the expression of p53 mRNA was lower than the control.</p><p><b>CONCLUSION</b>HBV X protein could transcriptionally inhibit the expression of p53 tumor suppression gene, which might be a possible molecular mechanism responsible for the development of HBV-associated hepatocellular carcinoma.</p>