title: Singlet oxygen, but not oxidizing radicals, induces apoptosis in HL-60 cells.
abstract: Oxidizing species (OS), produced by photosensitization or derived from cytotoxic agents, activate apoptotic pathways. We investigated whether two different OS, formed at the same subcellular sites, have equivalent ability to initiate apoptosis in HL-60 cells. Our previous work showed that absorption of visible light by rose bengal (RB) produces singlet oxygen exclusively, whereas absorption of ultraviolet A produces RB-derived radicals in addition to singlet oxygen. Singlet oxygen, but not the RB-derived radicals, induced nuclear condensation and DNA fragmentation into nucleosome-size fragments in a dose dependent manner. In contrast, the RB-derived radicals caused greater lipid oxidation than singlet oxygen. These results indicate that different OS, produced at the same subcellular sites, do not have the same ability to induce apoptosis and that the ability of an OS to initiate lipid oxidation does not necessarily correlate with its ability to induce apoptosis.
authors.affiliation: Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA. kochevar@helix.mgh.harvard.edu
authors.forename: I E
authors.initials: IE
authors.lastname: Kochevar
authors.forename: M C
authors.initials: MC
authors.lastname: Lynch
authors.forename: S
authors.initials: S
authors.lastname: Zhuang
authors.forename: C R
authors.initials: CR
authors.lastname: Lambert
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053938:DNA Fragmentation; D018922:HL-60 Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008027:Light; D017319:Photosensitizing Agents / Q000378:metabolism / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000502:physiology*; D012395:Rose Bengal / Q000378:metabolism / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D012395:Rose Bengal