title: The anti-leukaemic activity of novel synthetic naphthoquinones against acute myeloid leukaemia: induction of cell death via the triggering of multiple signalling pathways.
abstract: Naphthoquinones, such as menadione, display lower toxicity than anthracyclins used in cancer chemotherapy. Novel anti-leukaemic compounds comprised of chloro-amino-phenyl naphthoquinones with substitutions on the benzoic ring were developed. Structure-activity relationship studies indicated that the analogue with both methyl and amine substitutions (named TW-92) was the most efficient in killing leukaemic cells. Treatment of U-937 promonocytic cells with TW-92 induced apoptotic or necrotic cell death, dependent on incubation and dose conditions. TW-92 induced rapid phosphorylation of p38 mitogen-activated protein kinase (p38(MAPK)) and of extracellular signal-regulated protein kinases (ERK1/2). The generation of apoptosis was preceded by intracellular H(2)O(2) accumulation accompanied by glutathione depletion, the former inhibited by di-phenyl-iodonium (DPI), an inhibitor of NADPH oxidase. TW-92 induced swelling of isolated rat liver mitochondria, indicative of a direct effect on mitochondria. Apoptosis in intact cells was accompanied by a decrease in mitochondrial membrane potential, cytochrome c release and caspase activation. In addition, the level of Mcl-1, an anti-apoptotic regulatory protein, was down-regulated, whereas the expression of the pro-apoptotic BAX was elevated. Finally, TW-92 exerted strong pro-apoptotic and necrotic effects in primary acute myeloid leukaemia samples when given in submicromolar concentrations. Together, these findings demonstrate that TW-92 may provide an effective anti-leukaemic strategy.
authors.affiliation: Institute of Haematology, Soroka University Medical Centre, Beer-Sheva, Israel.
authors.forename: Maher
authors.initials: M
authors.lastname: Hallak
authors.forename: Thida
authors.initials: T
authors.lastname: Win
authors.forename: Ofer
authors.initials: O
authors.lastname: Shpilberg
authors.forename: Shmuel
authors.initials: S
authors.lastname: Bittner
authors.forename: Yosef
authors.initials: Y
authors.lastname: Granot
authors.forename: Itai
authors.initials: I
authors.lastname: Levy
authors.forename: Ilana
authors.initials: I
authors.lastname: Nathan
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism / Q000473:pathology*; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D020298:U937 Cells; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C548178:2-chloro-3-(3-amino-4-methyl-phenylamino)-1,4-naphthoquinone; D000970:Antineoplastic Agents; D009285:Naphthoquinones; D017382:Reactive Oxygen Species; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases