title: Histone deacetylase inhibitors potentiate TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in lymphoid malignancies.
abstract: New therapies are required for chronic lymphocytic leukemia (CLL), an incurable disease characterized by failure of mature lymphocytes to undergo apoptosis. Activation of cell surface death receptors, such as via TRAIL receptor ligation, may provide a novel therapeutic target for various malignancies. However, CLL and other lymphoid malignancies are resistant to TRAIL. We report that low concentrations of histone deacetylase (HDAC) inhibitors, such as depsipeptide, which alone failed to induce apoptosis, markedly sensitize CLL cells and other primary lymphoid malignancies to TRAIL-induced apoptosis. These combinations caused little or no toxicity to normal lymphocytes. HDAC inhibitors sensitized resistant cells to TRAIL-induced apoptosis by facilitating formation of an active death-inducing signalling complex (DISC), leading to the rapid activation of caspase-8. The facilitated DISC formation also occurred in the absence of TRAIL-R2 upregulation. Thus, the combination of HDAC inhibitors and TRAIL may be valuable in the treatment of various hemopoietic malignancies.
authors.affiliation: MRC Toxicology Unit, Hodgkin Building, University of Leicester, PO Box 138, Lancaster Road, Leicester LE1 9HN, UK.
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: MacFarlane
authors.forename: N
authors.initials: N
authors.lastname: Harper
authors.forename: L M C
authors.initials: LM
authors.lastname: Wheat
authors.forename: M J S
authors.initials: MJ
authors.lastname: Dyer
authors.forename: G M
authors.initials: GM
authors.lastname: Cohen
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D053181:Caspase 8; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D045744:Cell Line, Tumor; D003513:Cycloheximide / Q000494:pharmacology; D053418:Death Domain Receptor Signaling Adaptor Proteins; D047630:Depsipeptides / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D019169:Jurkat Cells / Q000187:drug effects; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D008214:Lymphocytes / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D020298:U937 Cells / Q000187:drug effects
chemical_list: D051017:Apoptosis Regulatory Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D047630:Depsipeptides; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D008562:Membrane Glycoproteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases