title: Inhibition of DNA methylation sensitizes glioblastoma for tumor necrosis factor-related apoptosis-inducing ligand-mediated destruction.
abstract: Life expectancy of patients affected by glioblastoma multiforme is extremely low. The therapeutic use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been proposed to treat this disease based on its ability to kill glioma cell lines in vitro and in vivo. Here, we show that, differently from glioma cell lines, glioblastoma multiforme tumors were resistant to TRAIL stimulation because they expressed low levels of caspase-8 and high levels of the death receptor inhibitor PED/PEA-15. Inhibition of methyltransferases by decitabine resulted in considerable up-regulation of TRAIL receptor-1 and caspase-8, down-regulation of PED/PEA-15, inhibition of cell growth, and sensitization of primary glioblastoma cells to TRAIL-induced apoptosis. Exogenous caspase-8 expression was the main event able to restore TRAIL sensitivity in primary glioblastoma cells. The antitumor activity of decitabine and TRAIL was confirmed in vivo in a mouse model of glioblastoma multiforme. Evaluation of tumor size, apoptosis, and caspase activation in nude mouse glioblastoma multiforme xenografts showed dramatic synergy of decitabine and TRAIL in the treatment of glioblastoma, whereas the single agents were scarcely effective in terms of reduction of tumor mass, apoptosis induction, and caspase activation. Thus, the combination of TRAIL and demethylating agents may provide a key tool to overcome glioblastoma resistance to therapeutic treatments.
authors.affiliation: Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Eramo
authors.forename: Roberto
authors.initials: R
authors.lastname: Pallini
authors.forename: Fiorenza
authors.initials: F
authors.lastname: Lotti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sette
authors.forename: Mariella
authors.initials: M
authors.lastname: Patti
authors.forename: Monica
authors.initials: M
authors.lastname: Bartucci
authors.forename: Lucia
authors.initials: L
authors.lastname: Ricci-Vitiani
authors.forename: Michele
authors.initials: M
authors.lastname: Signore
authors.forename: Giorgio
authors.initials: G
authors.lastname: Stassi
authors.forename: Luigi M
authors.initials: LM
authors.lastname: Larocca
authors.forename: Lucio
authors.initials: L
authors.lastname: Crinò
authors.forename: Cesare
authors.initials: C
authors.lastname: Peschle
authors.forename: Ruggero
authors.initials: R
authors.lastname: De Maria
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000008:administration & dosage; D001374:Azacitidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors*; D000077209:Decitabine; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008562:Membrane Glycoproteins / Q000008:administration & dosage; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D010750:Phosphoproteins / Q000378:metabolism; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D015398:Signal Transduction; D053221:TNF-Related Apoptosis-Inducing Ligand; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage
chemical_list: D051017:Apoptosis Regulatory Proteins; D015395:Histocompatibility Antigens Class I; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; C092039:PEA15 protein, human; D010750:Phosphoproteins; C032907:Q surface antigens; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505653:TNFSF10 protein, human; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000077209:Decitabine; D015254:DNA Modification Methylases; C505530:CASP8 protein, human; C505526:Casp8 protein, mouse; D053181:Caspase 8; D020169:Caspases; D001374:Azacitidine