Rare occurrence of p53 and ras gene mutations in preneoplastic and neoplastic mouse endometrial lesions induced by N-methyl-N-nitrosourea and 17β-estradiol

To examine K-, H-, or N-ras and p53 gene mutations in mouse endometrial carcinogenesis induced by N-methyl-N-nitrosourea and 17β-estradiol, we performed polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) in 13 adenocarcinomas and 11 other preneoplastic lesions. A significant shifted band in exon 5 of p53 using PCR-SSCP was detected in one of 13 adenocarcinomas. Direct sequencing showed that the mutation was TCA-to-TGA (Ser-to-End) transition. These results suggest that ras gene mutations were not related to carcinogenesis and inactivation of p53 may occur with low frequency during the mouse endometrial carcinogenesis in this model.