Detection of DNA-adducts in normal and tumorous human prostate biopsies by p-32 postlabeling

Prostate cancer is the most commonly diagnosed cancer in men and the second leading cause of male cancer deaths in the United States. Several risk factors have been identified for prostate cancer, including increased serum testosterone levels, dietary fat intake, and ethnicity. In attempts to detect DNA damage in prostate tissue, we examined in a pilot study 18 pairs (36 samples) of normal and tumorous tissue biopsies from patients ages 50-76 years. DNA was isolated from frozen tissue by solvent extractions with DNA yield ranging from 392-1925 mu g/g tissue (mean 849 +/- 339 mu g/g). Analysis of the DNA by the nuclease P1-mediated P-32-postlabeling assay revealed the presence of multiple adducts in all DNA samples, irrespective of whether the tissue was normal or tumorous. Adduct levels generally ranged from 1-34 (mean 8 +/- 8) per 10(9) nucleotides for normal tissue and 3-37 (mean 11 +/- 9) per 10(9) nucleotides for tumorous tissue. Our data suggest (i) accumulation of DNA adducts in both normal and tumorous tissues; (ii) chromatographic similarity of certain adducts; and (iii) on an average, somewhat higher adduct levels in tumorous than normal tissue. Due to the small sample size examined, it remains to be determined if these DNA adducts were related to any of the risk factors.