p53 mutations in MeIQ-induced mouse forestomach tumors.

A method was established for detecting mutations in the mouse p53 gene by cDNA-PCR-SSCP, using four cell lines which were derived from forestomach tumors induced in CDF, mice by 2-amino-3,4-dimethylimidazo [4,5-f]quinoline (MeIQ). All the cell lines were demonstrated to have mutations in exons 4, 5, 7 and 10, respectively, and the method was confirmed to be efficient and reliable. It was therefore used to analyse the role of p53 gene mutations in forestomach carcinogenesis induced by MeIQ, by examining four original tumors, one papilloma, two primary carcinomas and one lymph node metastasis. The papilloma (F 14) and the carcinoma (F 12) had mutations, but the lymph node metastasis of F 12 mouse (F 12 LN) did not. These results thus indicate that p53 mutations may occur relatively early but do not confer any predisposition for lymph node metastasis.