title: Differentiation inducing factor 3 mediates its anti-leukemic effect through ROS-dependent DRP1-mediated mitochondrial fission and induction of caspase-independent cell death.
abstract: Differentiation-inducing factor (DIF) defines a group of chlorinated hexaphenones that orchestrate stalk-cell differentiation in the slime mold Dictyostelium discoideum (DD). DIF-1 and 3 have also been reported to have tumor inhibiting properties; however, the mechanisms that underlie the effects of these compounds remain poorly defined. Herein, we show that DIF-3 rapidly triggers Ca2+ release and a loss of mitochondrial membrane potential (MMP) in the absence of cytochrome c and Smac release and without caspase activation. Consistently with these findings, we also detected no evidence of apoptosis in cells treated with DIF-3 but instead found that this compound induced autophagy. In addition, DIF-3 promoted mitochondrial fission in K562 and HeLa cells, as assessed by electron and confocal microscopy analysis. Importantly, DIF-3 mediated the phosphorylation and redistribution of dynamin-related protein 1 (DRP1) from the cytoplasmic to the microsomal fraction of K562 cells. Pharmacological inhibition or siRNA silencing of DRP1 not only inhibited mitochondrial fission but also protected K562 cells from DIF-3-mediated cell death. Furthermore, DIF-3 potently inhibited the growth of imatinib-sensitive and imatinib-resistant K562 cells. It also inhibited tumor formation in athymic mice engrafted with an imatinib-resistant CML cell line. Finally, DIF-3 exhibited a clear selectivity toward CD34+ leukemic cells from CML patients, compared with CD34- cells. In conclusion, we show that the potent anti-leukemic effect of DIF-3 is mediated through the induction of mitochondrial fission and caspase-independent cell death. Our findings may have important therapeutic implications, especially in the treatment of tumors that exhibit defects in apoptosis regulation.
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Alix
authors.initials: A
authors.lastname: Dubois
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Clemence
authors.initials: C
authors.lastname: Ginet
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Nathan
authors.initials: N
authors.lastname: Furstoss
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Amine
authors.initials: A
authors.lastname: Belaid
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Mohamed Amine
authors.initials: MA
authors.lastname: Hamouda
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Wedjene
authors.initials: W
authors.lastname: El Manaa
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.|Institut de Chimie de Nice (ICN), UMR 7272, Nice, France.|CHU de Nice, Service d'Hématologie Clinique, Nice, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cluzeau
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Marchetti
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Université de Nice Sophia Antipolis, Nice, France.|Team 3: Regulation of Caspase Dependent and Independent Cell Death, Nice, France.
authors.forename: Jean Ehrland
authors.initials: JE
authors.lastname: Ricci
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Jacquel
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Luciano
authors.affiliation: Université de Nice Sophia Antipolis, Nice, France.|Institut de Chimie de Nice (ICN), UMR 7272, Nice, France.
authors.forename: Mohsine
authors.initials: M
authors.lastname: Driowya
authors.affiliation: Université de Nice Sophia Antipolis, Nice, France.|Institut de Chimie de Nice (ICN), UMR 7272, Nice, France.
authors.forename: Rachid
authors.initials: R
authors.lastname: Benhida
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.|CHU de Nice, Service d'Hématologie Clinique, Nice, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Auberger
authors.affiliation: INSERM U1065 Centre Méditerranéen de Médecine Moléculaire, Nice, France.|Team 2: Cell Death, Differentiation, Inflammation and Cancer, Nice, France.|Equipe Labellisée Fondation ARC, Paris, France.|Université de Nice Sophia Antipolis, Nice, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Robert
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D014408:Biomarkers, Tumor / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D034281:Dynamins; D005260:Female; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D006588:Hexanones / Q000494:pharmacology*; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008819:Mice, Nude; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D063154:Mitochondrial Dynamics / Q000187:drug effects*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; D006588:Hexanones; D008869:Microtubule-Associated Proteins; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; C053433:1-((3,5-dichloro)-2,6-dihydroxy-4-methoxyphenyl)-1-hexanone; D020169:Caspases; D020558:GTP Phosphohydrolases; C110768:DNM1L protein, human; D034281:Dynamins
keywords: DIF-3; autophagy; cell death; leukemia; mitochondria fission