Abstract |
Infection with hepadnaviruses and exposure to aflatoxin B1 (AFB1) are considered to be major risk factors in the development of hepatocellular carcinoma (HCC) in humans. A high rate of p53 mutations at codon 249 has been reported in these tumors. The tree shrew (Tupaia belangeri chinensis) is a useful animal model for the development of HCC after human hepatitis B virus (HBV) infection or AFB1 treatment. Therefore, it was of particular interest to determine whether the p53 gene in tree shrew HCCs associated with HBV infection and/or with exposure to AFB1 is affected in the same manner as in human HCCs. We determined the tree shrew p53 wild-type nucleotide sequences by RT-PCR and automatic DNA-sequencing. Tree shrew wild-type p53 sequence showed 91.7 and 93.4% homologies with human p53 nucleotide and amino acids sequences, respectively, while it showed 77.2 and 73.7% homologies in mice. One HCC and normal liver tissue from AFB1 treated and one HCC from AFB1- and HBV-treated tree shrew showed no change in p53 sequences, while three HCCs from AFB1- and HBV-treated tree shrews showed point mutations in p53 sequences. One HCC showed point mutations at codon 275, which is on the DNA-binding domain of p53 gene, which might be a cause of gain-of-function during the development of HCC. As a result, our finding indicates that tree shrews exposed to AFB1 and/or HBV had neither codon 249 mutations nor significant levels of other mutations in the p53 gene, as is the case with humans.
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Authors | U S Park, J J Su, K C Ban, L Qin, E H Lee, Y I Lee |
Journal | Gene
(Gene)
Vol. 251
Issue 1
Pg. 73-80
(Jun 13 2000)
ISSN: 0378-1119 [Print] Netherlands |
PMID | 10863098
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- DNA, Complementary
- Tumor Suppressor Protein p53
- Aflatoxin B1
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Topics |
- Aflatoxin B1
(toxicity)
- Amino Acid Sequence
- Animals
- Base Sequence
- Carcinoma, Hepatocellular
(chemically induced, genetics, virology)
- Cloning, Molecular
- DNA Mutational Analysis
- DNA, Complementary
(chemistry, genetics)
- Disease Models, Animal
- Genes, Tumor Suppressor
(genetics)
- Hepatitis B
(virology)
- Hepatitis B virus
- Liver
(metabolism, pathology)
- Liver Neoplasms
(chemically induced, genetics, virology)
- Molecular Sequence Data
- Mutation
- Point Mutation
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Tumor Suppressor Protein p53
(genetics)
- Tupaiidae
(genetics)
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