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SENCAR mouse skin tumors produced by promotion alone have A to G mutations in codon 61 of the c-rasHa gene.
- Source :
-
Carcinogenesis [Carcinogenesis] 1994 Sep; Vol. 15 (9), pp. 1975-8. - Publication Year :
- 1994
-
Abstract
- SENCAR mice, developed by selective breeding for high susceptibility to skin carcinogenesis by initiation with 7,12-dimethylbenz[a]anthracene and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA), form squamous papillomas in approximately 20% of animals treated repeatedly with TPA, without chemical initiation. DNA from eight skin tumors produced by a TPA-only protocol and four cell lines derived from these tumors was amplified by polymerase chain reaction and analyzed by discriminative oligonucleotide hybridization using oligomers specific for various c-rasHa gene codon 61 sequences. Five tumors and three cell lines had CAA (wild-type) to CGA mutations. In addition, one tumor had a CAA to CTA mutation, for a total of six of eight tumors having an activating mutation at this codon. Two tumors and one cell line had no codon 61 mutations detectable by this method. Since tumors derived from promotion-only protocols presumably originated from constitutively initiated cells, we examined tumor-free skins of untreated newborn and eight-month-old retired breeders and of 78-88-week-old SENCAR mice of both sexes, which were treated with TPA for 10 weeks starting at age 16-28 weeks and were untreated thereafter. Only the wild-type c-rasHa gene codon 61 sequence was seen, suggesting that the constitutively initiated cell population, if present, is below the limit of detection by this method.
- Subjects :
- 9,10-Dimethyl-1,2-benzanthracene
Adenine
Animals
Base Sequence
Cytosine
DNA, Neoplasm analysis
DNA, Neoplasm genetics
Exons
Female
Mice
Mice, Inbred SENCAR
Mice, Nude
Molecular Sequence Data
Nucleic Acid Hybridization
Polymerase Chain Reaction
RNA
Tetradecanoylphorbol Acetate
Cocarcinogenesis
Codon
Genes, ras
Mutation
Papilloma chemically induced
Papilloma genetics
Skin Neoplasms chemically induced
Skin Neoplasms genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0143-3334
- Volume :
- 15
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Carcinogenesis
- Publication Type :
- Academic Journal
- Accession number :
- 7522983
- Full Text :
- https://doi.org/10.1093/carcin/15.9.1975