title: Resveratrol sensitizes acute myelogenous leukemia cells to histone deacetylase inhibitors through reactive oxygen species-mediated activation of the extrinsic apoptotic pathway.
abstract: Histone deacetylase inhibitors (HDACIs) activate the prosurvival nuclear factor-κB (NF-κB) pathway by hyperacetylating RelA/p65, whereas the chemopreventive agent resveratrol inhibits NF-κB by activating the class III histone deacetylase Sirt1. Interactions between resveratrol and pan-HDACIs (vorinostat and panobinostat) were examined in human acute myelogenous leukemia (AML) cells. Pharmacologically achievable resveratrol concentrations (25-50 μM) synergistically potentiated HDACI lethality in AML cell lines and primary AML blasts. Resveratrol antagonized RelA acetylation and NF-κB activation in HDACI-treated cells. However, short hairpin RNA Sirt1 knockdown failed to modify HDACI sensitivity, which suggests that factors other than or in addition to Sirt1 activation contribute to resveratrol/HDACI interactions. These interactions were associated with death receptor 5 (DR5) up-regulation and caspase-8 activation, whereas cells expressing dominant-negative caspase-8 were substantially protected from resveratrol/HDACI treatment, which suggests a significant functional role for the extrinsic apoptotic pathway in lethality. Exposure to resveratrol with HDACI induced sustained reactive oxygen species (ROS) generation, which was accompanied by increased levels of DNA double-strand breaks, as reflected in γH2A.X and comet assays. The free radical scavenger Mn(III)tetrakis(4-benzoic acid)porphyrin chloride blocked ROS generation, DR5 up-regulation, caspase-8 activation, DNA damage, and apoptosis, which indicates a primary role for oxidative injury in lethality. Analyses of cell-cycle progression and 5-ethynyl-2'-deoxyuridine incorporation through flow cytometry revealed that resveratrol induced S-phase accumulation; this effect was abrogated by HDACI coadministration, which suggests that cells undergoing DNA synthesis may be particularly vulnerable to HDACI lethality. Collectively, these findings indicate that resveratrol interacts synergistically with HDACIs in AML cells through multiple ROS-dependent actions, including death receptor up-regulation, extrinsic apoptotic pathway activation, and DNA damage induction. They also raise the possibility that S-phase cells may be particularly susceptible to these actions.
authors.affiliation: Department of Medicine, Virginia Commonwealth University, P.O. Box 980035, Richmond, VA 23298, USA.
authors.forename: Alae
authors.initials: A
authors.lastname: Yaseen
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hock
authors.forename: Roberto
authors.initials: R
authors.lastname: Rosato
authors.forename: Paul
authors.initials: P
authors.lastname: Dent
authors.forename: Yun
authors.initials: Y
authors.lastname: Dai
authors.forename: Steven
authors.initials: S
authors.lastname: Grant
mesh_terms: D000107:Acetylation / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics; D004357:Drug Synergism; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D008665:Metalloporphyrins / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D000077767:Panobinostat; D017382:Reactive Oxygen Species / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D000077185:Resveratrol; D016196:S Phase / Q000187:drug effects / Q000235:genetics; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism; D013267:Stilbenes / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D020298:U937 Cells; D015854:Up-Regulation / Q000187:drug effects; D000077337:Vorinostat
chemical_list: D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007211:Indoles; D008665:Metalloporphyrins; D016328:NF-kappa B; C498143:RELA protein, human; D017382:Reactive Oxygen Species; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D013267:Stilbenes; D051996:Transcription Factor RelA; C097284:manganese(III)-tetrakis(4-benzoic acid)porphyrin; D000077337:Vorinostat; D000077767:Panobinostat; D053181:Caspase 8; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D000077185:Resveratrol