title: Induction of murine teratocarcinoma cell differentiation by suppression of poly(ADP-ribose) synthesis.
abstract: Poly(ADP-ribose) synthesizing activity in mouse teratocarcinoma EC-A1 cells decreased markedly during differentiation induced by retinoic acid; the activities assayed in permeabilized cells decreased to 25% and 10% of the activity of control (uninduced cells) 2 and 3 days, respectively, after the addition of 0.1 microM retinoic acid to the culture medium. This change preceded changes in morphology and DNA synthesis, which became prominent after 4 days. The decrease in poly(ADP-ribose) synthesizing activity appeared to be caused by a diminution of the synthetase protein and not by a decrease in its catalytic activity, because the full activity disclosed by DNase I treatment decreased in parallel, albeit at about 20 times higher levels. When 8 mM 3-aminobenzamide or 10 mM nicotinamide, specific inhibitors of poly(ADP-ribose) synthetase, was added to the culture medium, the cells underwent differentiation after 7-9 days. An analogue, 3-aminobenzoic acid, which is not inhibitory to the synthetase, induced differentiation much less efficiently than did 3-aminobenzamide, and the effect of 3-aminobenzoic acid appeared to be ascribable to its potent cytotoxicity. Immunohistochemical analysis using anti-poly(ADP-ribose) antibody confirmed the marked reduction in poly(ADP-ribose) synthesizing activity in nuclei of the cells treated with retinoic acid or 3-aminobenzamide but not with 3-aminobenzoic acid. These results suggest that a decrease in poly(ADP-ribose) synthesis triggers differentiation of teratocarcinoma cells.
mesh_terms: D062365:Aminobenzoates / Q000494:pharmacology; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects; D051379:Mice; D009244:NAD+ Nucleosidase / Q000037:antagonists & inhibitors*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D013724:Teratoma / Q000473:pathology*; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D062365:Aminobenzoates; D001549:Benzamides; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D014212:Tretinoin; C025160:3-aminobenzamide; D011065:Poly(ADP-ribose) Polymerases; D009244:NAD+ Nucleosidase