Association of H-ras mutations with adenocarcinomas of the parotid gland.

We have examined 17 adenocarcinomas and 2 mixed tumors of the salivary glands for mutational activation of the oncogenes H-ras, K-ras and N-ras. The presence of mutations was determined by in vitro amplification of gene fragments spanning codons 12, 13 and 61 and the use of mutation-specific oligonucleotide hybridization. ras mutations were present in 3 of 13 adenocarcinomas (23%) of the parotid gland. The mutations were confirmed and characterized by means of cycle sequencing of polymerase chain reaction (PCR) fragments. In all 3 cases, the mutation was an A:T to G:C transition at the second position of codon 61 of the H-ras gene. This rather unusual ras mutation could provide a clue to identify one or more carcinogens involved in the pathogenesis of parotid cancer.