title: Hammerhead ribozyme against gamma-glutamylcysteine synthetase attenuates resistance to ionizing radiation and cisplatin in human T98G glioblastoma cells.
abstract: Glioblastoma cells are highly malignant and show resistance to ionizing radiation, as well as anti-cancer drugs. This resistance to cancer therapy is often associated with a high concentration of glutathione (GSH). In this study, the effect of continuous down-regulation of gamma-glutamylcysteine synthetase (gamma-GCS) expression, a rate-limiting enzyme for GSH synthesis, on resistance to ionizing radiation and cisplatin (CDDP) was studied in T98G human glioblastoma cells. We constructed a hammerhead ribozyme against a gamma-GCS heavy subunit (gamma-GCSh) mRNA and transfected it into T98G cells. (1) The transfection of the ribozyme decreased the concentration of GSH and resulted in G1 cell cycle arrest of T98G cells. (2) The transfection of the ribozyme increased the cytotoxicity of ionizing radiation and CDDP in T98G cells. Thus, hammerhead ribozyme against gamma-GCS is suggested to have potential as a cancer gene therapy to reduce the resistance of malignant cells to ionizing radiation and anti-cancer drugs.
authors.affiliation: Department of Biochemistry and Molecular Biology in Disease, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Nagasaki 852-8523.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tani
authors.forename: Shinji
authors.initials: S
authors.lastname: Goto
authors.forename: Kensaku
authors.initials: K
authors.lastname: Kamada
authors.forename: Katsuharu
authors.initials: K
authors.lastname: Mori
authors.forename: Yoshishige
authors.initials: Y
authors.lastname: Urata
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ihara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kijima
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ueyama
authors.forename: Shobu
authors.initials: S
authors.lastname: Shibata
authors.forename: Takahito
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002453:Cell Cycle; D002455:Cell Division; D002945:Cisplatin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm; D016193:G1 Phase / Q000187:drug effects / Q000528:radiation effects; D005721:Glutamate-Cysteine Ligase / Q000037:antagonists & inhibitors*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008957:Models, Genetic; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D016337:RNA, Catalytic / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011836:Radiation Tolerance / Q000187:drug effects*; D011839:Radiation, Ionizing; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D016337:RNA, Catalytic; D012333:RNA, Messenger; D011838:Radiation-Sensitizing Agents; C427204:hammerhead ribozyme; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D002945:Cisplatin