The Relationship between hepatitis B Virus-X Gene, P53 gene mutation and Hepatocellular Carcinoma in HBs Ag Negative Patients with and without HCV Infectio

Chronic hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma (HCC), however, its role in the transformation process remains unclear. HBV encodes a small protein, known as HBx, which is required for infection and has been implicated in hepatocarcinogenesis. There is a need to clarify latent HBV infection in HBsAg- and anti-hepatitis C virus (anti-HCV)-negative HCC in Egyptian population and involvement of HBx and p53 gene in these patients. Patients and methods: We have analyzed X gene expression by polymerase chain reaction (PCR) in malignant liver tissues obtained from 42 HCC patients with hepatitis B surface antigen (HBsAg)-negative or positive and 23 patients chronically infected by HCV as well as 15 liver samples from healthy patients were potentially donor for patients with liver transplant. All patients and controls were subjected to : thorough clinical examination, abdominal ultrasonography, liver biopsy and liver spiral CT. Liver function tests and serum alpha-fetoprotein (AFP), viral hepatitis markers for B & C and HCV RNA by reverse transcription PCR (RT-PCR) were measured. HBV-DNA and HBx gene were performed by PCR in the malignant and normal liver tissues of patients and controls. As well as serum p53 was measured for patients and controls. Results: There was a significant increase in liver enzymes, bilirubin, AFP and p53, in comparing the HCV patients and HCC with the control group, while prothrombin concentration was significantly decreased. In comparing HCV and HCC patient groups, there was also a significant increases in ALP, GGT, AFP and p53 levels in HCC group. While no significant difference was detected in the clinical presentation of HCV patients and HCC except for ascites which was significantly higher in HCC patients. The prevalence of HBV markers (Hbs Ag, Hbe Ag, Hbc Ab) and HCV Abs did not show significant difference between HCV infected group and HCC patients. On the other hand, HBx protein was positive in 57.1% cases of HCC patients, it was significantly higher in HCC patients than HCV infected group, however no cases were positive for HBx gene among healthy controls. In addition, HBs Ag was negative in 70.8% of HCC cases with HBx gene positive, and it was positive in 29.2% of the same cases, this means that the presence of HBx gene was significantly associated with absence of HBs Ag in serum of HCC patients. Moreover, anti-HCV was positive in 45.8% of HCC cases with HBx gene positive, and mutant p53 was positive in 75% of HCC cases with HBx gene positive which was significantly higher than HCC cases with negative HBx gene, suggesting that, the presence of HBx gene was significantly associated with p53 gene mutation. Conclusion: These results provide evidence for high expression of HBVx gene in the malignant tissue of HBsAg-negative HCC cases and the presence of this gene with some HCC cases positive for HCV suggesting its potential role in hepatic carcinogenesis following HBV and HCV infection