Analysis of 4-ABP-DNA adducts and p53 alterations in urinary bladder carcinoma

Background: Activated intermediates of 4-aminobiphenyl (4-ABP) are able to covalently interact with DNA to form adducts. There ir a large body of evidence indicating that carcinogen-DNA adduct formation can be one of the cancer initiating mechanisms. Materials and Methods. (4-ABP)-induced DNA damage in association with p53 overexpression and mutations were evaluated in specimens of urothelial bladder cancers from 106 patients. Results: 4-ABP-DNA adduct levels resulted higher in smokers compared to non smokers, with a borderline statistical value. p53 nuclear overexpression was related to tumor grading, while no significant correlation with stage, 4-ABP-DNA adducts, smoking habit, and disease recurrence could be observed. Concerning molecular analysis, p53 point mutations were found in 17 of 106 cases (16%) and mutational pattern was significantly associated both with higher grade and stage, but no correlation was found with disease recurrence. Conclusions: These results suggest that other sources, in addition to tobacco smoke, may contribute to 4-ABP-DNA adducts formation in bladder tissue and that p53 expression/mutation cannot be considered a prognostic factor in bladder cancer.