P53 GENE MUTATION IN N-BUTYL-N-(4-HYDROXYBUTYL)NITROSAMINE-INDUCED URINARY-BLADDER TUMORS AND N-METHYL-N-NITROSOUREA-INDUCED COLON TUMORS OF RATS

We analyzed p53 mutations in 17 N-butyl-N-(4-hydroxybutyl) nitrosamine -induced bladder transitional cell carcinomas (TCCs) with or without a reas of squamous cell carcinoma (SCC) of Long-Evans Cinnamon (LEG) and F344 rats, and in 7 N-methyl-N-nitrasourea-induced colon adenocarcino mas of LEC rats by polymerase chain reaction-single strand conformatio n polymorphism analysis and DNA sequencing. Of these bladder tumors, o ne TCC with moderately differentiated SCC had a T to G transversion mu tation at codon 141, leading to a Val to Gly amino acid change. No p53 mutation was found in colon adenocarcinomas. Thus a p53 gene mutation seems infrequent in these rat bladder and colon carcinogenesis models even in the late stage. (C) 1997 Elsevier Science Ireland Ltd.