N-methylnitrosourea-induced Ki-ras codon 12 mutations: early events in mouse thymic lymphomas.
Mol Carcinog
; 13(2): 89-95, 1995 Jun.
Article
en En
| MEDLINE
| ID: mdl-7605584
N-Methylnitrosourea (NMU)-induced codon 12 Ki-ras mutations were analyzed in premalignant thymic lymphomas from C57BL/6J mice by using a selective polymerase chain reaction amplification strategy. The frequency of codon 12 Ki-ras mutations was 67% (16 of 24) in NMU-treated animals with premalignant stage I disease. Previously, animals with different stages of disease had been analyzed for cytogenetic changes and for mutations in the p53 tumor suppressor gene. The genetic changes observed were early-activating codon 12 G35-->A transition mutations of the Ki-ras gene, followed closely by trisomy 15 and infrequent mutation of the p53 gene late in tumor development. The consistent and early detection of Ki-ras mutations in NMU-treated animals but not in untreated controls suggests that the mutations result from direct carcinogen exposure. Alternate pathways of NMU-induced thymic lymphomagenesis were implicated. One pathway involved putative NMU-induced mutations in other, non-ras oncogenes that cooperate with trisomy 15 to produce similar T-cell tumors. The frequency of p53 gene mutations in human and murine T-cell tumors is similar but low.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Lesiones Precancerosas
/
Neoplasias del Timo
/
Codón
/
Genes ras
/
Linfoma
/
Metilnitrosourea
/
Mutación
Tipo de estudio:
Screening_studies
Límite:
Animals
Idioma:
En
Revista:
Mol Carcinog
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos