title: Bystander effect-mediated gene therapy of gliomas using genetically engineered neural stem cells.
abstract: Since neural stem cells (NSCs) have the ability to migrate toward a tumor mass, genetically engineered NSCs were used for the treatment of gliomas. We first evaluated the "bystander effect" between NSCs transduced with the herpes simplex virus-thymidine kinase (HSVtk) gene (NSCtk) and C6 rat glioma cells under both in vitro and in vivo conditions. A potent bystander effect was observed in co-culture experiments of NSCtk and C6 cells. In the intracranial co-implantation experiments in athymic nude mice and Sprague-Dawley rats, the animals co-implanted with NSCtk and C6 cells and treated with ganciclovir (GCV) showed no intracranial tumors and survived more than 100 days, while those treated with physiological saline (PS) died of tumor progression. We next injected NSCtk cells into the pre-existing C6 tumor in rats and treated them with GCV or PS. The tumor volume was serially measured by magnetic resonance imaging. The tumor disappeared in six out of nine rats in the NSCtk/GCV group, while all the rats treated with PS died of tumor progression by day 21. The results indicate the feasibility of a novel gene therapy strategy for gliomas through a bystander effect generated by intratumoral injection of NSCtk cells and systemic GCV administration.
authors.affiliation: Department of Neurosurgery, Hamamatsu University School of Medicine, Handayama, Japan.
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Li
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tokuyama
authors.forename: Junkoh
authors.initials: J
authors.lastname: Yamamoto
authors.forename: Masayo
authors.initials: M
authors.lastname: Koide
authors.forename: Naoki
authors.initials: N
authors.lastname: Yokota
authors.forename: Hiroki
authors.initials: H
authors.lastname: Namba
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000473:pathology / Q000628:therapy* / Q000821:virology; D024201:Bystander Effect; D018920:Coculture Techniques; D003131:Combined Modality Therapy; D005260:Female; D015774:Ganciclovir / Q000627:therapeutic use; D018014:Gene Transfer Techniques; D005818:Genetic Engineering; D015316:Genetic Therapy; D005910:Glioma / Q000473:pathology / Q000628:therapy* / Q000821:virology; D008279:Magnetic Resonance Imaging; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D051381:Rats / Q000196:embryology; D017207:Rats, Sprague-Dawley; D018139:Simplexvirus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015996:Survival Rate; D013937:Thymidine Kinase / Q000235:genetics*; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D000998:Antiviral Agents; D013937:Thymidine Kinase; D015774:Ganciclovir