OBJECTIVETo investigate the deletion of p53 gene and amplification of HER-2 oncogene at chromosome 17 in primary hepatocellular carcinoma (HCC) and the clinical significance.

METHODSInterphase dual fluorescence in situ hybridization (FISH) was applied to detect the ratio of the number of p53 gene copy or HER-2 oncogene copy to that of chromosome 17 copy, to determine the p53 gene deletion and HER-2 oncogene amplification in nuclei prepared from 42 surgical specimens of HCC. Statistical analysis for their clinical significance was performed.

RESULTSLoss of p53 gene and amplification of HER-2 oncogene were detected in 27 (64.3%) and 9 (21.4%) of the 42 HCC respectively including 4 cases with low and 5 with high copy amplification. Six (14.3%) of 42 HCC showed simultaneously p53 gene deletion and HER-2 oncogene amplification. 61.9% (26/42) of HCC were polysomy 17, which correlated positively with p53 gene deletion (chi(2) = 12.286, P < 0.001). No close correlation between p53 gene loss and HER-2 oncogene amplification was found (chi(2) = 0.00, P = 1.00). Loss of p53 gene was related to the serum alpha-fetoprotein (AFP) level and the tumor size (P < 0.05). The postoperative 2-year survival rate (18.5%) of HCC patients with p53 gene deletion was significantly lower than postoperative 2-year survival rate (60.0%) of those without p53 gene loss (chi(2) = 7.467, P = 0.006). Meanwhile, HER-2 oncogene amplification showed a tendency of correlation with the tumor size (chi(2) = 2.973, P = 0.085), and the postoperative 2-year survival rate (0/9) of HCC patients with HER-2 oncogene amplification was significantly lower than those (42.4%) without HER-2 oncogene amplification (chi(2) = 3.977, P = 0.046).

CONCLUSIONThere were a high frequency of p53 gene deletion and a low frequency of HER-2 oncogene amplification in primary HCC, which might be involved in initiation and development of a subset of primary HCC.