title: RIP3 is downregulated in human myeloid leukemia cells and modulates apoptosis and caspase-mediated p65/RelA cleavage.
abstract: The receptor-interacting protein kinase 3 (RIP3) associates with RIP1 in a necrosome complex that can induce necroptosis, apoptosis, or cell proliferation. We analyzed the expression of RIP1 and RIP3 in CD34+ leukemia cells from a cohort of patients with acute myeloid leukemia (AML) and CD34+ cells from healthy donors. RIP3 expression was significantly reduced in most AML samples, whereas the expression of RIP1 did not differ significantly. When re-expressed in the mouse DA1-3b leukemia cell line, RIP3 induced apoptosis and necroptosis in the presence of caspase inhibitors. Transfection of RIP3 in the WEHI-3b leukemia cell line or in the mouse embryonic fibroblasts also resulted in increased cell death. Surprisingly, re-expression of a RIP3 mutant with an inactive kinase domain (RIP3-kinase dead (RIP3-KD)) induced significantly more and earlier apoptosis than wild-type RIP3 (RIP3-WT), indicating that the RIP3 kinase domain is an essential regulator of apoptosis/necroptosis in leukemia cells. The induced in vivo expression of RIP3-KD but not RIP3-WT prolonged the survival of mice injected with leukemia cells. The expression of RIP3-KD induced p65/RelA nuclear factor-κB (NF-κB) subunit caspase-dependent cleavage, and a non-cleavable p65/RelA D361E mutant rescued these cells from apoptosis. p65/RelA cleavage appears to be at least partially mediated by caspase-6. These data indicate that RIP3 silencing in leukemia cells results in suppression of the complex regulation of the apoptosis/necroptosis switch and NF-κB activity.
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: A-L
authors.initials: AL
authors.lastname: Nugues
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: H
authors.initials: H
authors.lastname: El Bouazzati
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: D
authors.initials: D
authors.lastname: Hétuin
authors.affiliation: 1] Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France [2] Service des Maladies du Sang, Centre Hospitalier et Universitaire de Lille, Rue Polonovski, Lille F-59045, France.
authors.forename: C
authors.initials: C
authors.lastname: Berthon
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: A
authors.initials: A
authors.lastname: Loyens
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: E
authors.initials: E
authors.lastname: Bertrand
authors.affiliation: Université Lille Nord de France, Lille F-59045, France.
authors.forename: N
authors.initials: N
authors.lastname: Jouy
authors.affiliation: Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France.
authors.forename: T
authors.initials: T
authors.lastname: Idziorek
authors.affiliation: 1] Inserm, U837, Institut pour la Recherche sur le Cancer de Lille, place de Verdun, Lille F-59045, France [2] Service des Maladies du Sang, Centre Hospitalier et Universitaire de Lille, Rue Polonovski, Lille F-59045, France [3] Université Lille Nord de France, Lille F-59045, France.
authors.forename: B
authors.initials: B
authors.lastname: Quesnel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053178:Caspase 6 / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008875:Middle Aged; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D061945:Caspase Inhibitors; D016328:NF-kappa B; D051996:Transcription Factor RelA; C119705:RIPK3 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D053178:Caspase 6; D020169:Caspases