Codon 249 mutations of p53 gene in non-neoplastic liver tissues.

AIM:To study the significance of p53 gene in hepatocarcinogenesis through analyzing codon 249 mutations of p53 gene in non-neoplastic liver tissues.METHODS:Codon 249 mutation was detected using single-stranded conformational polymorphism analysis and allele-specific PCR in liver tissues from 10 cases of chronic hepatitis, 5 cases of cirrhosis and 20 cases of HCCs.RESULTS:The detection rate of codon 249 mutation in chronic hepatitis, cirrhosis and pericancerous tissues was 70% (7/10), 100% (5/5) and 70% (14/20), respectively by AS-PCR. These mutations could not be detected by SSCP analysis. The detection rates were 65% (13/20) and 45% (9/20) in cancerous tissues by AS-PCR and SSCP analysis.CONCLUSION:Codon 249 mutations of p53 gene were very popular in non-neoplastic liver tissues though the number of those mutant cells was only in subsection. Those mutations in cancerous tissues might take place in the stage before the formation of tumor.

Immunohistochemical detection of HCV infection in patients with hepatocellular carcinoma and other liver diseases.

AIM:To detect HCV infection in patients with HCC and other liver diseases by the immunohistochemical method.METHODS: The expression of HCV antigen was identified by means of LSAB (labelled streptavidin-biotin) method using anti-NS3 monoclonal antibody.RESULTS: The positive rates of HCV antigen in the three groups of HCC, liver cirrhosis and hepatitis were 13.5% (7/52), 12.5% (2/16), and 10% (4/40) respectively, while in the samples from patients with constitutional jaundice and normal liver samples, no HCV antigen was found. HCV antigen could be seen in the nuclei and/or cytoplasms of carcinoma cells and/or pericancerous hepatocytes. In HCC, HCV antigen was more often seen in nuclei than in cytoplasms. The positive rate of HCV antigen in pericancerous tissues was higher than that in cancerous tissues.CONCLUSION: HCV is associated with HCC,and HCV infection enhances the development of liver diseases. HCV affects the initiative period of HCC and induces the malignant phenotypic alteration of hepatocytes.

Codon 249 mutations of p53 gene in development of hepatocellular carcinoma.

AIM:To investigate the mechanisms of codon 249 mutation of p53 gene in the formation of hepatocellular carcinoma (HCC).METHODS:Codon 249 mutation accompanied by loss of heterozygosity (LOH) and its effect on translation and transcription were studied using SSCP, IHC and RT-PCR/slot hybridization.RESULTS:Codon 249 mutations were detected in 32.9%, LOH detected in 68.4% among the HCC patients.Mutations of condon 249 were accompanied by LOH in 90%.The positive rates of p53 protein and mRNA were 91.3% and 95.7%, in mutational group, both were significantly higher than those in the non-mutational group (91.3% vs 19.1% and 95.7% vs 40.4%, respectively, both P < 0.01). The translation of p53 gene was strongly related to its transcription by correlation analysis( r = 0.8208).CONCLUSION:LOH might play an important role in hepatocarcinogenesis of codon 249 mutation, which could increase both transcription and translation of p53 gene.The increased expression of p53 protein mainly depend on the increased transcription of p53 gene.