Activation of a c-K-ras oncogene by somatic mutation in mouse lymphomas induced by gamma radiation
Mouse tumors induced by gamma radiation are a useful model system for oncogenesis. DNA from such tumors contains an activated K-ras oncogene that can transform NIH 3T3 cells. This report describes the cloning of a fragment of the mouse K-ras oncogene containing the first exon from both a transformant in rat-2 cells and the brain of the same mouse that developed the tumor. Hybrid constructs containing one of the two pieces were made and only the plasmid including the first exon from the transformant gave rise to foci in NIH 3T3 cells. There was only a single base difference (G----A) in the exonic sequence, which changed glycine to aspartic acid in the transformant. By use of a synthetic oligonucleotide the presence of the mutation was demonstrated in the original tumor, ruling out modifications during DNA-mediated gene transfer and indicating that the alteration was present in the thymic lymphoma but absent from other nonmalignant tissue. The results are compatible with gamma radiation being a source of point mutations.
- Research Organization:
- New York Univ. Medical Center, New York
- OSTI ID:
- 6240247
- Journal Information:
- Science (Washington, D.C.); (United States), Vol. 225:4667
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENES
CLONING
TUMOR CELLS
ONCOGENIC TRANSFORMATIONS
DNA
GAMMA RADIATION
MICE
MUTATIONS
NEOPLASMS
PLASMIDS
RADIOINDUCTION
ANIMAL CELLS
ANIMALS
CELL CONSTITUENTS
DISEASES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATIONS
RODENTS
VERTEBRATES
560121* - Radiation Effects on Cells- External Source- (-1987)