title: Doxorubicin enhances TRAIL-induced cell death via ceramide-enriched membrane platforms.
abstract: Previous studies indicated that signalling via CD95 and DR5 is greatly enhanced by the formation of ceramide-enriched membrane platforms. Here, we employed this concept to convert doses of subtherapeutic TRAIL that were unable to release ceramide and kill leukemic B-cells or ex vivo T lymphocytes, into a very effective apoptotic stimulus. Ceramide production was induced by application of sub-toxic doses of doxorubicin that resulted in an activation of the acid sphingomyelinase (ASM), release of ceramide and formation of ceramide-enriched membrane platforms. The latter served DR5 to cluster after application of very low doses of TRAIL in combination with doxorubicin. Genetic deficiency of the ASM abrogated doxorubicin-induced ceramide release, as well as clustering of DR5 and apoptosis induced by the combined treatment of doxorubicin and TRAIL. These data show that local release of ceramide potentiates very low, otherwise inactive doses of TRAIL that may represent a novel therapeutic concept to treat tumors.
authors.affiliation: Department of Molecular Biology, University of Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany.
authors.forename: Claudia Alexandra
authors.initials: CA
authors.lastname: Dumitru
authors.forename: Alexander
authors.initials: A
authors.lastname: Carpinteiro
authors.forename: Tanja
authors.initials: T
authors.lastname: Trarbach
authors.forename: Ulrich R
authors.initials: UR
authors.lastname: Hengge
authors.forename: Erich
authors.initials: E
authors.lastname: Gulbins
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000008:administration & dosage / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D021962:Membrane Microdomains / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D002518:Ceramides; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; D004317:Doxorubicin