Analysis of C-Ha-ras gene amplification and mutation in laryngeal carcinoma.

In order to study the altered molecular events during laryngeal carcinogenesis and elucidate the role of Ha-ras oncogene amplification and mutation, we have examined their profile by polymerase chain reaction (PCR) and selective oligonucleotide hybridization. We analyzed the mutational status of codon 12 of Ha-ras in 22 laryngeal carcinomas and 10 normal tissues, and found that 7 of 22 laryngeal carcinomas contained a Ha-ras mutation at codon 12. The frequency of mutation was 32%. None of the normal tissues revealed mutation. Moreover, no amplification was found in cancers when compared to the normal. Our findings indicated that the activated Ha-ras gene existed in laryngeal carcinoma, and activation of the Ha-ras gene by mutation at codon 12 might play a key role in laryngeal carcinogenesis.