title: Effect of 15-lipoxygenase metabolites, 15-(S)-HPETE and 15-(S)-HETE on chronic myelogenous leukemia cell line K-562: reactive oxygen species (ROS) mediate caspase-dependent apoptosis.
abstract: Growth inhibitory effects of 15-lipoxygenase-1 [13-(S)-HPODE and 13-(S)-HODE] and 15-lipoxygenase-2 [15-(S)-HPETE and 15-(S)-HETE] (15-LOX-1 and LOX-2) metabolites and the underlying mechanisms were studied on chronic myeloid leukemia cell line (K-562). The hydroperoxy metabolites, 15-(S)-HPETE and 13-(S)-HPODE rapidly inhibited the growth of K-562 cells by 3h with IC(50) values, 10 and 15microM, respectively. In contrast, the hydroxy metabolite of 15-LOX-2, 15-(S)-HETE, showed 50% inhibition only at 40microM by 6h and 13-(S)-HODE, hydroxy metabolite of 15-LOX-1, showed no significant effect up to 160microM. The cells exposed to 10microM of 15-(S)-HPETE and 40microM of 15-(S)-HETE showed typical apoptotic features like release of cytochrome c, caspase-3 activation and PARP-1 (poly(ADP) ribose polymerase-1) cleavage. A flow cytometry based DCFH-DA analysis and inhibitory studies with DPI, a pharmacological inhibitor of NADPH oxidase, NAC (N-acetyl cysteine) and GSH revealed that NADPH oxidase-mediated generation of ROS is responsible for caspase-3 activation and subsequent induction of apoptosis in the K-562 cell line.
authors.affiliation: Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Suraneni V K
authors.initials: SV
authors.lastname: Mahipal
authors.forename: Jagu
authors.initials: J
authors.lastname: Subhashini
authors.forename: Madhava C
authors.initials: MC
authors.lastname: Reddy
authors.forename: Metukuri M
authors.initials: MM
authors.lastname: Reddy
authors.forename: Kotha
authors.initials: K
authors.lastname: Anilkumar
authors.forename: Karnati R
authors.initials: KR
authors.lastname: Roy
authors.forename: Gorla V
authors.initials: GV
authors.lastname: Reddy
authors.forename: Pallu
authors.initials: P
authors.lastname: Reddanna
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001093:Arachidonate 15-Lipoxygenase / Q000502:physiology; D053148:Caspase 3 / Q000502:physiology*; D002374:Catalase / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D005434:Flow Cytometry; D005979:Glutathione Peroxidase / Q000502:physiology; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D020014:K562 Cells; D015289:Leukotrienes / Q000494:pharmacology*; D008054:Lipid Peroxides / Q000494:pharmacology*; D019255:NADPH Oxidases / Q000502:physiology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D006893:Hydroxyeicosatetraenoic Acids; D015289:Leukotrienes; D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D045304:Cytochromes c; D002374:Catalase; D005979:Glutathione Peroxidase; C458528:ALOX15B protein, human; D001093:Arachidonate 15-Lipoxygenase; D019255:NADPH Oxidases; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3