Downstream signaling in doxazosin-induced apoptosis.

Doxazosin treatment induced cleavage of effector caspases 7 (B) and 3 (D), associated with unaltered expression of pre-processed caspase 3 and 7 levels in LNT-229 cells (A, C). (E) Enhanced cleavage (inactivation) of poly-ADP-ribose-polymerase (PARP) was observed with increasing concentrations of doxazosin, representing a characteristic apoptotic step. (F) Autophagy-associated phagocytosis of dead cells is indicated by increased levels of the lower migrating form of microtubule-associated protein 1 light chain 3 (LC3). Typical Western blots and mean (± SEM) optical densities normalized to drug-free conditions are shown (n = 3 independent assays; *p<0.05; **p<0.01; GAPDH, glyceraldehyde-3-phosphate dehydrogenase).