title: Stimulation of repair replication by 3-aminobenzamide in human fibroblasts with ligase I deficiency.
abstract: A cell line deficient in DNA ligase I and sensitive to poly(ADP-ribose) inhibitors, 46BR, was used to examine the relationship between DNA ligation and a large stimulation of repair replication that is seen in cells grown in a poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide (3AB), after exposure to alkylating agents. Repair replication was stimulated at least 10-fold by 3AB in both normal and ligase-deficient cells. Despite increased 3AB toxicity, repair replication in ligase I-deficient cells was unchanged from that in normal cells. This evidence is consistent with previous observations that the enhancement of repair replication by 3AB is not a direct function of DNA break frequencies. The stimulation may instead result from alkylation damage to other cellular organelles that release nucleases that cause additional damage to DNA, which cells attempt to repair.
authors.affiliation: Laboratory of Radiobiology and Environmental Health, University of California, San Francisco 94143-0750, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Cleaver
mesh_terms: D001549:Benzamides / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D011088:DNA Ligases / Q000172:deficiency*; D004260:DNA Repair / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D000067856:Poly(ADP-ribose) Polymerase Inhibitors
chemical_list: D001549:Benzamides; D004791:Enzyme Inhibitors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D008769:Methylnitronitrosoguanidine; C025160:3-aminobenzamide; D011088:DNA Ligases; D002118:Calcium