[Mutational activation of H-ras and K-ras (Codon 12,61) genes in 7,12 dimethylbenz(a)anthracene induced rat ovarian tumors].

We had studied the histogenesis and p21 expression in ovarian tumor induced by 7,12-dimethylbenz(a)anthracene (DMBA). The present study was done to elucidate point mutation of the ras gene in tumors. Cases with immunohistological p21 expression; 3 adenomas, 5 adenocarcinomas and 2 sarcomas were examined by polymerase chain reaction (PCR). 1) The products of PCR were confirmed the presence of amplified sequences by electrophoresis. 2) No point mutation of H-ras (Codon 12,61) or K-ras (Codon 12,61) genes was found in the ovarian tumors induced by DMBA. 3) These results suggested that the mutational activation of ras genes in tumorigenesis was dependent on another mechanism.