Temporal relationships between inhibitory effects of glucocorticoids on cells of the CEM-C7 human leukaemic lymphoblast cell line.
Events preceding glucocorticoid-induced growth inhibition and cytolysis were studied in CEM-C7 human leukaemic lymphoblasts. Inhibitory effects on uridine and thymidine incorporation and on RNA polymerase A activity preceded cell killing, and may relate to the arrest of the cells in the G1 phase of the cell cycle. An inhibitory effect on RNA polymerase B activity emerged later than the effect on RNA polymerase A; this action may reflect commitment to cell death. Cell death was not apparent within the first 24 hr of steroid treatment but thereafter was associated with extensive DNA fragmentation. The lethal action of dexamethasone in CEM-C7 cells was potentiated by 3-aminobenzamide, an inhibitor of poly(ADP-ribose)polymerase.
D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors; D003907:Dexamethasone / Q000494:pharmacology*; D006801:Humans; D007399:Interphase / Q000187:drug effects; D007942:Leukemia, Experimental / Q000188:drug therapy*
D001549:Benzamides; D003907:Dexamethasone; C025160:3-aminobenzamide; D012321:DNA-Directed RNA Polymerases