INHIBITORS OF POLY(ADP-RIBOSE) POLYMERASE SUPPRESS NUCLEAR FRAGMENTATION AND APOPTOTIC-BODY FORMATION DURING APOPTOSIS IN HL-60 CELLS

The effects of 3-aminobenzamide (3ABm) and benzamide (BAm), known spec ific inhibitors of poly(ADP-ribose) polymerase (PARP), on actinomycin D (Act D)-induced apoptosis in HL-60 cells were examined, These inhibi tors had no appreciable effect on apoptotic DNA fragmentation, chromat in condensation or PARP restriction cleavage, but clearly inhibited mo rphological changes, especially nuclear fragmentation and apoptotic-bo dy formation, in a dose-dependent manner, These results suggest that t he synthesis of ADP-ribose polymers is not essential for the progressi on of apoptotic DNA fragmentation and chromatin condensation, but is r equired in the processes leading to nuclear fragmentation and the subs equent apoptotic-body formation during apoptosis in HL-60 cells. (C) 1 997 Federation of European Biochemical Societies.