title: Role of oxygen radicals generated by NADPH oxidase in apoptosis induced in human leukemia cells.
abstract: We have used a human leukemia cell line that, after homologous recombination knockout of the gp91-phox subunit of the phagocyte respiratory-burst oxidase cytochrome b-558, mimics chronic granulomatous disease (X-CGD) to study the role of oxygen radicals in apoptosis. Camptothecin (CPT), a topoisomerase I inhibitor, induced significantly more apoptosis in PLB-985 cells than in X-CGD cells. Sensitivity to CPT was enhanced after neutrophilic differentiation, but was lost after monocytic differentiation. No difference between the two cell lines was observed after treatment with other apoptosis inducers, including etoposide, ultraviolet radiation, ionizing radiation, hydrogen peroxide, or 7-hydroxystaurosporine. After granulocytic differentiation of both cell lines, CPT still induced apoptosis, suggesting independence from replication in fully differentiated and growth-arrested cells. Pyrrolidine dithiocarbamate (an antioxidant inhibitor of NF-kappaB) and catalase partially inhibited CPT-induced DNA fragmentation in granulocytic-differentiated PLB-985 cells, but had no effect in X-CGD cells. Flow cytometry analysis revealed that reactive oxygen intermediates were generated in CPT-treated PLB-985 cells. These data indicate that oxygen radicals generated by NADPH oxidase may contribute directly or indirectly to CPT-induced apoptosis in human leukemia and in neutrophilic-differentiated cells.
authors.affiliation: Laboratory of Molecular Pharmacology, National Cancer Institute, Bethesda, Maryland 20892, USA.
authors.forename: W
authors.initials: W
authors.lastname: Hiraoka
authors.forename: N
authors.initials: N
authors.lastname: Vazquez
authors.forename: W
authors.initials: W
authors.lastname: Nieves-Neira
authors.forename: S J
authors.initials: SJ
authors.lastname: Chanock
authors.forename: Y
authors.initials: Y
authors.lastname: Pommier
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D002166:Camptothecin / Q000494:pharmacology*; D002374:Catalase / Q000494:pharmacology; D002454:Cell Differentiation; D002460:Cell Line; D053938:DNA Fragmentation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D005434:Flow Cytometry; D006105:Granulomatous Disease, Chronic / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007938:Leukemia / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000502:physiology*; D009000:Monocytes / Q000473:pathology; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D009363:Neoplasm Proteins / Q000378:metabolism*; D009504:Neutrophils / Q000473:pathology; D011759:Pyrrolidines / Q000494:pharmacology; D017382:Reactive Oxygen Species; D019311:Staurosporine / Q000031:analogs & derivatives; D013859:Thiocarbamates / Q000494:pharmacology; D059004:Topoisomerase I Inhibitors; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
chemical_list: D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D009363:Neoplasm Proteins; D011759:Pyrrolidines; D017382:Reactive Oxygen Species; D013859:Thiocarbamates; D059004:Topoisomerase I Inhibitors; C020972:pyrrolidine dithiocarbamic acid; D005047:Etoposide; C054852:7-hydroxystaurosporine; D006861:Hydrogen Peroxide; D002374:Catalase; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D019311:Staurosporine; D002166:Camptothecin