Tumorigenic methylcholanthrene transformants of C3H/10T1/2 cells have a common nucleotide alteration in the c-Ki-ras gene.
The polymerase chain reaction was used to amplify DNA surrounding the codon 12 region of the c-Ki-ras gene from C3H/10T1/2 cells and from a number of 3-methylcholanthrene (MCA)-transformed derivatives of these cells. Sequence analysis demonstrated that tumorigenic MCAC116/39 cells, known by DNA-mediated transfection to contain an activated c-Ki-ras oncogene, had a G----T transversion in the first position of codon 12 of this gene, resulting in a Gly12----Cys mutation. A combination of polymerase chain-reaction amplification and oligonucleotide hybridization demonstrated that three additional tumorigenic MCA transformants of C3H/10T1/2 cells had an identical mutation in the c-Ki-ras gene. In contrast, this mutation was not present in an MCA-induced C3H/10T 1/2 transformant that was not tumorigenic. The molecular specificity of this MCA-induced mutation resulting in C3H/10T1/2 tumorigenic transformants should provide an excellent system in which to study the roles of transcription, replication, repair, and exogenous factors in the establishment and expression of transformation and tumorigenicity.
Chen
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Molecular Biology Institute, University of California, Los Angeles Center for the Health Sciences 90024.
Herschman
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D000818:Animals; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D003001:Cloning, Molecular / Q000379:methods; D003062:Codon / Q000235:genetics; D005784:Gene Amplification; D011905:Genes, ras / Q000187:drug effects*; D008748:Methylcholanthrene / Q000494:pharmacology*; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization
D003062:Codon; D008748:Methylcholanthrene