Four human carcinoma cell lines with novel mutations in position 12 of c-K-ras oncogene.

We have used synthetic oligonucleotides to probe for mutations affecting amino acid 12 of the c-K-ras gene in human cell line DNA. Of seven carcinoma cell lines tested, four were found to contain a mutation at this position. In each the nucleotide G was replaced with an A resulting in a Gly to Asp substitution in three cases (cell lines A427, A1165 and A1663) and Gly to Ser in the fourth (A549). Neither of these substitutions have been previously reported in either human tumor or human tumor-derived cell line DNA's. These results indicate that association between mutations involving position 12 of the human c-K-ras oncogene and carcinomas may be stronger than previously recognized.