Fluorescence and mass spectral evidence for the formation of benzo[a]pyrene anti-diol-epoxide—DNA and —hemoglobin adducts in humans

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Abstract
Highly specific methods are required to detect and quantitate carcinogen—macromolecular adducts in humans who are exposed to complex mixtures of chemical carcinogens. High performance liquid chromatography and fluorescence spectroscopy have been used successfully to detect and identify residues of benzo[a]pyrene-7, 10/8, 9-tetrahydrotetrol (BP-7, 10/8, 9-tetrol) that were released upon mild acid hydrolysis of human DNA or hemoglobin. Synchronous fluorescence spectroscopy data indicate that levels of benzo[a]pyrene-diol-epoxide—DNA (BPDE—DNA) adducts as high as 1.54 fmol BPDE/μg DNA are formed (1 adduct in 5 million nucleotides) in peripheral blood lymphocytes of coke-oven workers; these data were subsequently corroborated by gas chromatography/mass spectroscopy single ion monitoring analysis (m/z 404+). Additionally, among lung cancer patients, 5 samples of tumor DNA were found to be negative and 1 of 4 samples of corresponding lung tissue was found to be positive. Extraction and purification of BP-7, 10/8, 9-tetrol from the hemoglobin of smokers suggested levels of bound carcinogen in excess of 1 ng BPDE/gm of hemoglobin. High performance liquid chromatography combined with synchronous fluorescence spectroscopy provides a highly specific method for the detection of covalently bound BP residues in both human hemoglobin and DNA.