Induction of apoptosis in HL-60 cells by photochemically generated hydroxyl radicals.

Reactive oxygen species (ROS), especially hydroxyl radicals are postulated to mediate apoptosis of the cell. Here we demonstrate that hydroxyl radicals generated selectively by photolysis of a photo-Fenton reagent, N,N'-bis(2-hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthaldiimide (NP-III), induce apoptosis in HL-60 (human promyelocytic leukemia) cells involving the activation of caspase-3.