RESUMO
<p><b>OBJECTIVE</b>To investigate the association of mutations in the hepatitis B virus (HBV) X gene (HBX, encoding the HBx protein) and development of hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>Forty-four patients with HBV-related HCC participated in the study, along with 76 patients with chronic HBV infection who assessed as controls. All patients had serum HBV DNA levels that were higher than 10(3) copies/ml. Extracted HBV DNA was subjected to nested PCR to amplify the HBX gene, followed by direct sequencing. All sequencing data were compared to the consensus HBV sequence to identify mutations. The sequencing data were analyzed by Chromas and SeqMan software.</p><p><b>RESULTS</b>Mutations of G1467C, G/C1479A, C1485T and C1653T in the X region were found, but did not show any significant difference in occurrence between the HCC group and the chronic HBV infection group (P>0.05). The T1674C mutation in the X region, however, occurred more frequently in the HCC group (29.27% vs.6.67%, P<0.05). Prevalence of the T1753C mutation and the A1762T/G1764A double mutation in the BCP region was significantly higher in the HCC group than in the chronic HBV infection group (P<0.05) and in the group of patients with hepatitis B e antigen (HBeAg)-negative status compared to the patients with HBeAg-positive status (P<0.05).</p><p><b>CONCLUSION</b>Incidence of the T1674C mutation in the X region and of the T1753C mutation and the A1762T/G1764A double mutation in the BCP region was higher for patients with HBV-related HCC; the T1753C mutation and the A1762T/G1764A double mutation may inhibit the formation of HBeAg.</p>