title: A human gastric carcinoma contains a single mutated and an amplified normal allele of the Ki-ras oncogene.
abstract: The DNA from various human tumors and tumor cell lines was screened for the presence of mutated ras oncogenes with synthetic oligonucleotide probes, as well as with the NIH/3T3 cell transfection assay. Among the various mutations found we discovered two novel Ki-ras mutations in codon 12: gly to ala and gly to ser. A gastric carcinoma was found to possess a single mutated Ki-ras allele (gly-12 to ser), as well as a 30-50 fold amplified normal allele. This implies that two activating steps must have occurred in this malignancy.
mesh_terms: D000483:Alleles; D000818:Animals; D002277:Carcinoma / Q000235:genetics*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D005784:Gene Amplification; D006801:Humans; D051379:Mice; D009154:Mutation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000235:genetics; D009857:Oncogenes; D013274:Stomach Neoplasms / Q000235:genetics*; D014162:Transfection
chemical_list: D009841:Oligonucleotides