Hammerhead ribozyme against gamma-glutamylcysteine synthetase attenuates resistance to ionizing radiation and cisplatin in human T98G glioblastoma cells.
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.
Tani
Masaharu
M
Department of Biochemistry and Molecular Biology in Disease, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Nagasaki 852-8523.
Goto
Shinji
S
Kamada
Kensaku
K
Mori
Katsuharu
K
Urata
Yoshishige
Y
Ihara
Yoshito
Y
Kijima
Hiroshi
H
Ueyama
Yoshito
Y
Shibata
Shobu
S
Kondo
Takahito
T
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
D000970:Antineoplastic Agents; D016337:RNA, Catalytic; D012333:RNA, Messenger; D011838:Radiation-Sensitizing Agents; C427204:hammerhead ribozyme; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D002945:Cisplatin