Deoxycholic acid-induced apoptosis is switched to necrosis by bcl-2 and calphostin C

We previously demonstrated that the cytotoxicity associated with exposure o f HCT116 cells to deoxycholic acid was due to the induction of apoptosis. H ere we show that this results in activation of caspase 3 and that over expr ession of bcl-2 can suppress this. Surprisingly, inhibition of apoptosis by over expression of bcl-2 or incubation with calphostin C, a PKC inhibitor, did not enhance cell survival, but instead caused a switchover to death by necrosis. Hence, DCA-induced apoptosis requires caspase activity and both bcl-2 and PKC can determine the type of cell death induced by deoxycholic a cid. (C) 2000 Elsevier Science Ireland Ltd, All rights reserved.