HEPATITIS-B VIRUS PREC MUTANTS IN HUMAN HEPATOCELLULAR-CARCINOMA TISSUES

A comparative analysis of preC sequences of hepatitis B virus (HBV) in human hepatoma (hepatocellular carcinoma; HCC) tissues and non-tumoral liver samples from HCC patients was performed. Ten out of 17 HCC tissue samples exhibited an amino acid substitution at the level of the distal cysteine residue of the HBV preC region, while generation of a TAG translational stop codon was observed in 4 of these samples. Interestingly, substitution of the distal cysteine residue was not observed in non-tumoral liver (available from 8 of the 17 patients), thus suggesting either that a selection among different HBV variants occurs in HCC cells, or that modifications to the conformation and stability of the HBV capsid protein may play a role in the process of selection and escape of transformed liver cells.