title: Glioma regression in vitro and in vivo by a suicide combined treatment.
abstract: We present here a suicide therapy against malignant gliomas based on the transfer to tumor cells of a gene encoding a beta-glucosidase, linamarase (lis), which in the presence of the innocuous substrate linamarin (lin) produces cyanide, blocking the mitochondrial respiratory chain. Dog glioma cells carrying the lis gene are thus sensitive to lin (IC(50) of 250 microg/mL at 48 hours) and cell death is accompanied by mitochondrial fission and ATP depletion. The combination of lis/lin with an otherwise nontoxic level of glucose oxidase (GO) enhances the therapeutic potential (IC(50) of 50 microg/mL at 48 hours). GO produces hydrogen peroxide, inducing oxidative damage and increasing cellular stress. We show here the antitumoral effect of the lis/lin/GO therapy in a canine glioma cell line and in a xenograft glioma model in nude mice. The synergic combination causes mitochondrial membrane depolarization and phosphatidylserine externalization and accelerates death by 48 hours. The lethal process is caspase independent; poly(ADP-ribose) polymerase 1 is not implicated; and there is no apoptosis-inducing factor translocation to the nucleus. The combined system induces autophagic cell death that can be rescued by 3-methyladenine and is characterized by the presence of double-membrane vesicles and punctate LC-3 pattern.
authors.affiliation: Department of Molecular Biology, Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Vega
authors.initials: V
authors.lastname: García-Escudero
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gargini
authors.forename: Marta
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000627:therapeutic use; D000111:Acetylcysteine / Q000627:therapeutic use*; D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology* / Q000628:therapy*; D016923:Cell Death / Q000187:drug effects; D004285:Dogs; D004359:Drug Therapy, Combination; D005910:Glioma / Q000473:pathology* / Q000628:therapy*; D005949:Glucose Oxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D009570:Nitriles / Q000627:therapeutic use*
chemical_list: D009570:Nitriles; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; C025946:3-methyladenine; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; C005091:linamarin; D000225:Adenine; D000111:Acetylcysteine