BENZO[A]PYRENE DIOL-EPOXIDE-I-DNA AND OXIDATIVE DNA-ADDUCTS ASSOCIATED WITH GASTRIC ADENOCARCINOMA

BPDE-I-DNA and oxidative DNA adducts (8-OHdG) were investigated in sto mach tissues (tumor and tumor-adjacent) of patients (N = 211) with gas tric adenocarcinoma and in normal stomach tissues (N = 113). In each s tomach specimen, the levels of BPDE-I-DNA adducts were quantitatively measured by enzyme linked immunosorbent assay (ELISA) and oxidative DN A damage was measured by HPLC-ECD. Higher levels of total BPDE-I-DNA a dduct were observed in tumor (4.20 +/- 0.59 fmol/mu g DNA) and tumor-a djacent (3.68 +/- 0.62 fmol/mu g DNA) tissues than in normal stomach t issues (2.80 +/- 0.53 fmol/mu g DNA) but were not significant. In male s, BPDE-I-DNA adduct was significantly higher in tumor tissues (4.25 /- 0.42 fmol/mu g DNA) than in normal tissues (2.83 +/- 0.59 fmol/mu g DNA) (P < 0.05). In smokers, BPDE-I-DNA adduct was slightly higher in tumor tissues (4.92 +/- 0.82 fmol/mu g DNA) than in tumor-adjacent ti ssues (3.99 +/- 0.92 fmol/mu g DNA). Gastric cancer patients had signi ficantly higher levels of 8-OHdG in their tumor-adjacent (7.54 +/- 0.4 3 residues/10(5) dG) and tumor tissues (6.29 +/- 0.39 residues/10(5) d G) than in normal tissues (2.86 +/- 0.11 residues/10(5) dG) (P < 0.001 ). Smokers showed higher levels of 8-OHdG in both tumor (6.44 +/- 0.62 residues/10(5) dG) and tumor-adjacent (8.12 +/- 0.68 residues/10(5) d G) tissues than in non-smokers (5.80 +/- 0.47 and 7.11 +/- 0.57 residu es/10(5) dG, respectively). 8-OHdG levels were significantly increased in positive tissues with Helicobacter pylori (H. pylori) infection co mpared with negative tissues (P < 0.01). Also, the frequency of H. pyl ori infection was higher in tumor-adjacent tissues (73%) than in tumor (42%) or normal tissues (44%). These results demonstrate that there a re higher levels of 8-OHdG and BPDE-I-DNA adducts in tumor and tumor-a djacent tissues than in normal tissues and that these higher levels mi ght be related to gastric tumorigenesis, although benzo[a]pyrene could be a minor contributing component in the environment. (C) 1998 Elsevi er Science Ireland Ltd.