title: Endoplasmic reticulum targeting in Ewing's sarcoma by the alkylphospholipid analog edelfosine.
abstract: Ewing's sarcoma (ES) is the second most common bone cancer in children and young people. Edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) is the prototype of a family of synthetic antitumor compounds, collectively known as alkylphospholipid analogs (APLs). We have found that APLs ranked edelfosine>perifosine>erucylphosphocholine>miltefosine for their capacity to promote apoptosis in ES cells. Edelfosine accumulated in the endoplasmic reticulum (ER) and triggered an ER stress response that eventually led to caspase-dependent apoptosis in ES cells. This apoptotic response involved mitochondrial-mediated processes, with cytochrome c release, caspase-9 activation and generation of reactive oxygen species. Edelfosine-induced apoptosis was also dependent on sustained c-Jun NH2-terminal kinase activation. Oral administration of edelfosine showed a potent in vivo antitumor activity in an ES xenograft animal model. Histochemical staining gave evidence for ER stress response and apoptosis in the ES tumors isolated from edelfosine-treated mice. Edelfosine showed a preferential action on ES tumor cells as compared to non-transformed osteoblasts, and appeared to be well suited for combination therapy regimens. These results demonstrate in vitro and in vivo antitumor activity of edelfosine against ES cells that is mediated by caspase activation and ER stress, and provide the proof of concept for a putative edelfosine- and ER stress-mediated approach forES treatment.
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.
authors.forename: Ximena
authors.initials: X
authors.lastname: Bonilla
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.|Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK.
authors.forename: El-Habib
authors.initials: el-H
authors.lastname: Dakir
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain.
authors.forename: Faustino
authors.initials: F
authors.lastname: Mollinedo
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Gajate
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis; D001859:Bone Neoplasms / Q000188:drug therapy*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D010742:Phospholipid Ethers / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D012512:Sarcoma, Ewing / Q000188:drug therapy*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D010742:Phospholipid Ethers; C026659:edelfosine
keywords: Ewing’s sarcoma; apoptosis; edelfosine; endoplasmic reticulum; ether phospholipid; xenograft animal model