Mutations of the Apc gene in experimental colorectal carcinogenesis induced by azoxymethane in F344 rats

We investigated in the rat the role of the Ape gene, which is mutated in familial adenomatous polyposis and sporadic colon cancer in the process leading from normal colonic mucosa to aberrant crypt foci (ACF) and finally to adenomas and adenocarcinomas. We analysed mutations in exon 15 of the rat Ape gene using in vitro synthesized protein assay in 66 ACF and in 28 colon rumours induced by azoxymethane. No Ape mutations were found in ACF, whereas five mutations were found in the rumours, The data suggest that mutations of the Ape gene are associated with the transition from ACF to adenoma and adenocarcinoma and not from normal mucosa to ACF.