title: NF-kappaB activation prevents apoptotic oxidative stress via an increase of both thioredoxin and MnSOD levels in TNFalpha-treated Ewing sarcoma cells.
abstract: Repression of activation of c-Jun N-terminal kinase (JNK) participates in the anti-apoptotic effect of nuclear factor-kappaB (NF-kappaB) in TNFalpha-treated Ewing sarcoma cells. As oxidative stress is one of the most prominent activators of JNK, we investigated the relationship between TNFalpha-induced NF-kappaB activation and the control of oxidative stress. Inhibition of NF-kappaB activation resulted in an increase in TNFalpha-induced ROS production, lipid peroxidation and protein oxidation. Those ROS and lipid peroxides were both involved in TNFalpha-induced apoptosis, whereas only ROS elevation triggered sustained JNK activation. TNFalpha increased the level of two antioxidant enzymes, thioredoxin and manganese superoxide dismutase by an NF-kappaB-dependent mechanism. Inhibition of expression or activity of these enzymes sensitized cells to TNFalpha-induced apoptosis, indicating their functional role in protection from cell death. Thus, agents that inhibit activities of these enzymes may prove helpful in the treatment of Ewing tumors.
authors.affiliation: INSERM U365, Institut Curie, Section de recherche, 26 rue d'Ulm, 75248 Paris cedex 05, France. mergny@vjf.inserm.fr
authors.forename: Mojgan
authors.initials: M
authors.lastname: Djavaheri-Mergny
authors.forename: Delphine
authors.initials: D
authors.lastname: Javelaud
authors.forename: Juana
authors.initials: J
authors.lastname: Wietzerbin
authors.forename: Françoise
authors.initials: F
authors.lastname: Besançon
mesh_terms: D000293:Adolescent; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002648:Child; D004789:Enzyme Activation; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D015227:Lipid Peroxidation; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D012512:Sarcoma, Ewing / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D013879:Thioredoxins / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D013879:Thioredoxins; D013482:Superoxide Dismutase; D048031:JNK Mitogen-Activated Protein Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases