Detection of hepatitis B virus DNA and mutations in K-ras and p53 genes in human hepatocellular carcinomas

Hepatitis B virus (HBV) infection is considered as one of the major risk factors in the development of human hepatocellular carcinoma (HCC). Recent studies have also suggested the implication of oncogene and onco-suppressor genes in liver carcinogenesis. We studied 41 cases of HCC for the presence of HBV DNA and point mutations in codon 12 of K-ras and codon 249 of p53. We used 'nested' PCR for the amplification of HBV because of the expected low incidence of the virus DNA in the samples. PCR was also used for the amplification of K-ras and p53 regions that contain the codons of interest, followed by RFLP analysis for the detection of point mutations. HBV DNA was amplified in 22 cases (53.7%), while 5 cases (12.2%) appeared to carry mutations in codon 12 of K-ras and 7 cases (17.1%) had mutations in codon 249 of the p53 gene. These results further support the correlation between HBV infection and HCC and also indicate an implication of K-ras and p53 genes in hepatocarcinogenesis.