Inhibition of replicative DNA synthesis and induction of DNA repair in human fibroblasts by the intercalating drugs proflavine and 9‐aminoacridine

Abstract

The induction of unscheduled DNA synthesis (UDS) and the alteration of semiconservative DNA replication by the structurally related intercalating agents proflavine and 9-aminoacridine were studied in MRC-5 human fibroblasts in culture. Autoradiographic determinations of both parameters were carried out simultaneously in the same culture specimens. Proflavine affected DNA synthesis, but did not elicit any UDS. 9-Aminoacridine inhibited DNA synthesis only at the highest concentration and caused UDS to a low but significant extent. These results suggest that the ability to induce UDS is not a general property of the intercalating agents and that the alterations of the DNA structure, typical of the "pure" intercalative process, are not handled by pathways involving unscheduled synthesis.