To determine if hemizygous transgenic mice carrying the human c-Ha-ras gene (CB6F1-Tg Hras2 mice (Hras2 mice)) are susceptible to the carcinogenic potential of known murine carcinogens, male and female Hras2 mice and their non-transgenic CB6F1 littermates (non-Tg mice) were each given a single intra
Activating mutation of the Ha-ras gene in chemically induced tumors of the hamster cheek pouch
โ Scribed by Irma B. Gimenez-Conti; Albert B. Bianchi; Sharon L. Stockman; Claudio J. Conti; Thomas J. Slaga
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 471 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0899-1987
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โฆ Synopsis
Abstract
The presence of an activating mutation in the Haโras gene in hamster cheek pouch tumors induced by 7,12โdimethylbenz[a]anthracene (DMBA) complete carcinogenesis was investigated. The normal sequence of a fragment of genomic DNA encompassing codon 61 of the Haโras gene was amplified by the polymerase chain reaction using primers designed for a highly conserved region of the mouse Haโrasโ1 gene. The sequence of the amplified fragment was determined by a direct sequencing technique and exhibited 83.3% and 87.5% homology with the corresponding human and mouse sequences, respectively. At the amino acid level, the sequence was identical among the three species. Paraffin sections of 11 squamous cell carcinomas of the cheek pouch were used to detect mutated Haโras alleles. DNA sequencing of the tumors showed that six of 11 tumors presented an AโT transversion in the second position of codon 61, resulting in an amino acid change from glycine to leucine. As has been demonstrated in other systems, we have shown a specific mutation of the Haโras gene in chemically induced tumors of the hamster cheek pouch, further supporting the role of this oncogene in chemical carcinogenesis. ยฉ 1992 WileyโLiss, Inc.
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