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p53 gene mutation spectrum in hepatocellular carcinoma
1Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
Cancer Research
|November 15, 1992
Summary
p53 gene mutations are significant in hepatocellular carcinoma (HCC) development, particularly in poorly differentiated tumors. These mutations occur independently of viral infections and are associated with chromosome 17p loss.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Hepatocellular carcinoma (HCC) is a major global health concern.
- The role of the p53 tumor suppressor gene in HCC development is crucial but requires further clarification, especially in low-exposure regions.
Purpose of the Study:
- To investigate the incidence, type, and location of p53 gene mutations in Japanese HCC patients.
- To determine the association between p53 mutations and clinicopathological features of HCC.
Main Methods:
- Single-strand conformation polymorphism analysis and direct sequencing of p53 gene in 169 HCC tissue samples.
- Restriction fragment length polymorphism analysis to assess loss of heterozygosity on chromosome 17p.
Main Results:
- p53 mutations were found in 29% of HCCs, with a higher incidence (54%) in poorly differentiated tumors compared to well or moderately differentiated ones (21%).
- Mutations predominantly occurred in conserved domains IV and V, with codon 249 being the most frequent site.
- Loss of heterozygosity on chromosome 17p was observed in 69% of informative cases, and in 95% of cases with p53 mutations.
Conclusions:
- p53 gene mutations are a significant event in HCC progression, occurring independently of viral hepatitis infection or pre-existing liver disease.
- These mutations are preferentially associated with moderately and poorly differentiated HCCs and likely occur late in tumorigenesis, often following the loss of the other p53 allele.