title: APO2 ligand: a novel lethal weapon against malignant glioma?
abstract: APO2L (TRAIL) is a novel CD95L (Fas/APO-1-L) homologous cytotoxic cytokine that interacts with various receptors which transmit (DR4, DR5) or inhibit (DcR1, DcR2) an apoptotic signal. Here, we report that human glioma cell lines preferentially express mRNAs for agonistic death receptors DR4 (8/12) and DR5 (11/12) rather than the death-inhibitory decoy receptors DcR1 (4/12) and DcR2 (2/12). Ten of 12 cell lines are susceptible to APO2L-induced apoptosis. The resistant cell lines, U138MG and U373MG, are cross-resistant to CD95L-induced apoptosis. Similar to CD95L-induced apoptosis, APO2L-induced apoptosis is inhibited by ectopic expression of the caspase inhibitor, crm-A, or of bcl-2, or by coexposure to the corticosteroid, dexamethasone, or the lipoxygenase inhibitor, nordihydroguaretic acid. There is no correlation between p53 genetic status of the cell lines and their susceptibility to APO2L-induced apoptosis, but the latter is moderately enhanced by ectopic expression of wild-type p53. APO2L targeting may be a promising approach for selectively targeting apoptosis to human malignant glioma cells.
authors.affiliation: Department of Neurology, University of Tübingen, School of Medicine, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Rieger
authors.forename: U
authors.initials: U
authors.lastname: Naumann
authors.forename: T
authors.initials: T
authors.lastname: Glaser
authors.forename: A
authors.initials: A
authors.lastname: Ashkenazi
authors.forename: M
authors.initials: M
authors.lastname: Weller
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D051017:Apoptosis Regulatory Proteins; D005910:Glioma / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D051017:Apoptosis Regulatory Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha