CHARACTERIZATION OF ROOM-TEMPERATURE INDUCED APOPTOSIS IN HL-60

We found that exposure to room temperature (RT/21 degrees C) causes ap optosis in HL-60 cells, Here we characterized RT-induced apoptosis in HL-60, After exposure to RT, apoptosis starts within 6 h and more than 80% of the cells underwent apoptosis within 20 h, All cells, however, were committed to apoptosis after 16 h and no viable cells could be r ecovered, The caspase-1 inhibitor (YVAD-CHO) effectively blocked apopt osis, whereas the caspase-3 inhibitor (DEVD-CHO) did not. About 20% of newly obtained early passage HL-60 cells (passage 10) also underwent apoptosis by RT treatment, These data suggest that some population in HL-60 which responds to RT with apoptosis became dominant during passa ging. (C) 1997 Federation of European Biochemical Societies.