Identification of benzo[a]pyrene 7,8-diol 9,10-epoxide N2-deoxyguanasine in human lung adenocarcinoma cells exposed to cooking oil fumes from frying fish under domestic conditions

Lung cancer is the most common cause of cancer death among women in Taiwan. Epidemiological studies of lung cancer in Chinese women indicate that fact ors other than cigarette smoking are related to lung cancer risk. One such factor may be exposure to carcinogens formed during the cooking of food. Th e carcinogenic compounds in oil smoke particulates from Chinese cooking pra ctice have not yet been characterized. To reveal the relationship between t he high mortality rate of lung cancer in Chinese women and exposure to cook ing oil fumes (COF), DNA adduct formation, induced by COF collected from fr ying fish under domestic conditions, was assessed in human lung adenocarcin oma CL-3 cell lines using the P-32-postlabeling assay. DNA adduct levels we re induced by COF in CL-3 cells in a dose-dependent manner. DNA adducts wit h a diagonal radioactive zone (DRZ) were observed when CL-3 cells were trea ted with COF. Surprisingly, only one spot of the DNA adduct profile was in the DRZ. The DNA adduct was analyzed by HPLC coupled with an on-line radioa ctive detector. The retention time of the major DNA adduct corresponded to that of authentic benzo[alpha ]pyrene 7,8-diol 9,10-epoxide N2-deoxyguanons ine (BPDE-N2-dG). Moreover, the mass spectrum of the major DNA adduct in CL -3 cells was confirmed to be BPDE-N2-dG by liquid chromatography/mass spect rometry. In conclusion, BPDE-N2-dG adduct formation in human lung cells sup ports epidemiological findings of an association between cooking fume expos ure and lung cancer in Chinese women.