METABOLIC-ACTIVATION OF THE FOOD MUTAGENS 2-AMINO-3-METHYLIMIDAZO[4,5-F]QUINOLINE (IQ) AND 2-AMINO-3,4-DIMETHYLIMIDAZO[4,5-F]QUINOLINE (MEIQ) TO DNA-BINDING SPECIES IN HUMAN MAMMARY EPITHELIAL-CELLS

When incubated in suspension with the heterocyclic aromatic amine food mutagens 2-amino-3-methylimidazo [4,5-f]-quinoline (IQ) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), human mammary epithelial cell aggregates were found, by P-32-postlabelling analysis, to yield DNA that contained adducts. Analysis by HPLC of the P-32-labelled digests of mammary cell DNA indicated that in each case a major adduct peak corresponded to that produced in DNA in vitro by activated derivatives of the two compounds. The patterns of adducts obtained when DNA digests were separated by TLC on polyethyleneimine-cellulose plates were found to resemble those previously shown to be present in DNA of tissues of mice fed IQ or MeIQ. These results demonstrate the ability of human mammary epithelial cells to activate carcinogenic heterocyclic compounds known to be present in the human diet to DNA binding derivatives.