Analysis of Hepatitis B Virus Pre-S Gene in Hepatocellular Carcinoma and Paracancerous Tissues from Southern China

Gene in Abstract: Chronic hepatitis B virus (HBV) infection is one of the major causes of hepatocellular carcinoma (HCC), and the HBV pre-S gene plays a critical role in the molecular pathogenesis of HBV-related HCC. We have investigated whether there are particular HBV pre-S gene mutations associated with HCC in patients from southern China. The HBV pre-S gene was examined in 100 paraffin-embedded tumor tissue and 100 paraffin-embedded paracancerous tissue samples from patients with HCC by nested polymerase chain reaction (PCR). The HBV pre-S genes with potentially important mutations from tumor tissue samples were sequenced and aligned with the published HBV pre-S gene sequence. Twelve patients (12.0%) had pre-S mutations; six had a pre-S1 deletion, one patient had a pre-S2_ deletion, five patients had both a pre-S deletion, and a pre-S2 mutation. Among them, two patients contained pre-S1 insertion and two patients contained pre-S1 start codon mutation. Two patients (2.0%) of hepatocellular carcinoma paracancerous tissue had pre-S mutation and two patients had pre-S1 + pre-S2 deletion. The pre-S sequence of HBV contained stop codon in four patients of HCC, leading to truncated pre-S protein and changed protein structure. These results suggest that HBV pre-S gene deletion mutation and insertion mutation in HCC tissues and paracancerous tissues lead to truncated HBV pre-S protein or protein changes, which may be related to the occurrence of hepatocellular carcinoma.