从肝癌组织中发现乙型肝炎病毒核心抗原编码基因突变

DETECTION OF HEPATITIS B VIRUS C GENE VARIATION IN HEPATOCELLULAR CARCINOMA

Thirty three hepatocellular carcinoma tissues were hybridized separately with hepatitis B virus ( HBV ) surface ( S ) and core ( C ) genes. Fourteen out of 33 were S positive, whereas only 3/14 were C gene positive. These 3C gene positive liver cancer tissues were amplified for C( including Pre-C gene)gene by polymerase chain reaction,further cloned and sequenced. Comparing with the HBV adr subtype clone ( pADR-1 ) nucleotide sequence, there were point mutations in all 3 clones, including transition and trans-version but no frame shift. There was a shared point mutation at the 1,898 nucleotide sequence in 2 clones, which was a transition from guanine to adenine,leading to a stop codon in the pre-C region, 2 codons upstream from the ATG of C gene. Since one of the clones was isolated from a sample which revealed only replicating form of C gene,an HBV C gene variant was implied. Although most point mutations were neutral, some amino acid alterations were present,hut no regularity of alterations was detected. Studies on the potential biological significance of this variant are being pursued.