A HOT-SPOT FOR P53 MUTATION IN TRANSITIONAL-CELL CARCINOMA OF THE BLADDER - CLUES TO THE ETIOLOGY OF BLADDER-CANCER

Twenty-eight transitional cell carcinomas of the bladder, grade 2 or 3 , were analyzed for the presence of p53 mutations. Thirteen tumors wer e found to contain 14 mutations. These were all base substitution muta tions, of which nine were GC --> AT transitions (three at CpG sites). The remaining five mutations were transversions (three GC --> CG, one GC --> TA, and one AT --> TA). Four of the mutations were found at cod on 280. A comparison with other studies of bladder tumors reveals that a region encompassing codons 280 and 285 represents a hot spot for p5 3 mutation in bladder cancer. The 280/285 hot spot lies within two pur ine-rich sequences that may provide some clues to the identity of pote ntial bladder carcinogens. A comparison of mutations from bladder tumo rs of smokers and nonsmokers reveals no significant differences.