Capability of human blood cells to form the DNA adduct, C8-(N2-aminofluorenyl)-deoxyguanosine-3'-5'-diphosphate from 2-aminofluorene.

Human blood cells, separated by Ficoll-Hypaque centrifugation, were tested for their ability to catalyze the formation of DNA adducts of 2-aminofluorene (AF), using the 32P-postlabeling procedure for adduct analysis. Incubation of neutrophils with AF, hydrogen peroxide and exogenous DNA yielded a single DNA adduct identified as C8-(N2-aminofluorenyl)-deoxyguanosine-3'-5'-diphosphate (AFdG) by cochromatography with a standard sample. AFdG levels in intact cells, lysed cells and in the granule fraction prepared from cell lysates were 102, 894 and 240 AFdG adducts/10(9) nucleotides/30 min respectively. AFdG levels corresponded to the activity of neutrophil peroxidase in these preparations. The monocyte/lymphocyte fraction yielded a low amount of 30 and 40 AFdG/10(9) nucleotides/30 min in the presence of hydrogen peroxide and of NADPH respectively. Erythrocytes did not generate a detectable level of AFdG, neither as intact cells nor as cell lysates. Whole blood samples likewise did not generate AFdG. Our findings reveal that, among blood cells, only neutrophils are capable of forming a biologically significant DNA adduct of aminofluorene in reasonable amounts and suggest that myeloperoxidase was the catalyzing enzyme.