Evidence that mutational activation of the ras genes may not be involved in aflatoxin B1–induced human hepatocarcinogenesis, based on sequence analysis of the ras and p53 genes
✍ Scribed by Hung-Kun Chao; Ting-Fen Tsai; Chang-Shen Lin; Tsung-Sheng Su
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 143 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0899-1987
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✦ Synopsis
Exposure to aflatoxin B 1 (AFB 1 ) is one of the risk factors for developing hepatoma. In rats, activation of the ras gene is a prevalent event in AFB 1 -induced hepatocarcinogenesis. It is not clear whether a similar event occurs in humans. By analysis of codon 249 of the p53 gene, six of 36 human hepatoma samples were found to show a G 3 T transversion, suggesting that AFB 1 may be a risk factor for hepatocarcinogenesis. However, analysis at codons 12, 13, and 61 in the ras family genes revealed a A 3 T transversion at codon 61 of the N-ras gene in a single tumor. Apparently, ras activation is rare in human hepatoma, and the mutation detected might not be induced by AFB 1 . This suggests that activation of the ras gene may not be a major event in AFB 1 -related human hepatocarcinogenesis.