High incidence of nitrosamine-induced tumorigenesis in mice lacking DNA repair methyltransferase.
Carcinogenesis
; 18(8): 1631-5, 1997 Aug.
Article
em En
| MEDLINE
| ID: mdl-9276640
ABSTRACT
The enzyme O6-methylguanine-DNA methyltransferase repairs alkylation-induced DNA damage, O6-methylguanine and O4-methylthymine, the former being formed more frequently. Previously, by means of gene targeting, we generated mice in which alleles for methyltransferase were disrupted. We now use these mouse lines, which are totally deficient in methyltransferase activity, to examine protective effects of the enzyme against tumor formation. In gene-targeted female mice given an i.p. injection of 5 mg/kg of dimethylnitrosamine, a larger number of liver and lung tumors occurred, as compared with normal female mice treated in the same manner. In male mice given a lower dose of carcinogen, the difference between normal and gene-targeted mice was statistically insignificant although more tumors did form in the gene-targeted mice. Methyltransferase apparently afforded protection from nitrosamine-induced tumorigenesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Hepáticas
/
Neoplasias Pulmonares
/
Metiltransferases
Tipo de estudo:
Incidence_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Carcinogenesis
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Japão