title: Mechanism of hydrogen peroxide-induced apoptosis of the human osteosarcoma cell line HS-Os-1.
abstract: In our previous study, we examined radiation-induced ROS formation, oxidative DNA damage, early apoptotic changes, and mitochondrial membrane dysfunction in the human osteosarcoma cell line HS-Os-1, which was established from an osteoblastic tumor that arose in the left humerus of an 11-year-old girl and was already morphologically characterized in vitro and in vivo. We found that ROS formation and oxidative DNA damage were scarcely seen after irradiation of up to 30 Gy in these cells; that mitochondrial membrane potential was preserved; and that apoptotic changes were not demonstrated despite the relatively high-dose irradiation of 30 Gy. Based on these results, the radioresistance of the human osteosarcoma cell line HS-Os-1, was considered to arise, at least in part, from the low level of ROS formation following irradiation, which in turn may have resulted from the strong scavenging ability of the cells for free radicals, including hydroxyl radicals. Therefore, in this study, we examined the effect of exogenous hydrogen peroxide, which causes a potent oxidative stress and has been demonstrated to be a potent apoptosis-inducer in many kinds of cells. We found that addition of 1 or 10 mM hydrogen peroxide induced ROS formation, oxidative DNA damage, dysfunction of the mitochondrial membrane potential, and early apoptotic changes in the human osteosarcoma cell line HS-Os-1. We therefore concluded that intracellular ROS formation is involved in the hydrogen peroxide-induced apoptosis of HS-Os-1 cells.
authors.affiliation: Department of Radiology, Kochi Medical School, Oko-cho, Nankoku-shi, Kochi-Prefecture 783-8505, Japan. ogaway@kochi-ms.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shinji
authors.initials: S
authors.lastname: Kariya
authors.forename: Akihito
authors.initials: A
authors.lastname: Nishioka
authors.forename: Hiroo
authors.initials: H
authors.lastname: Mizobuchi
authors.forename: Masataka
authors.initials: M
authors.lastname: Noguchi
authors.forename: Shinji
authors.initials: S
authors.lastname: Hamasato
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Tani
authors.forename: Harumichi
authors.initials: H
authors.lastname: Seguchi
authors.forename: Shoji
authors.initials: S
authors.lastname: Yoshida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sonobe
mesh_terms: D017304:Annexin A5 / Q000494:pharmacology; D017209:Apoptosis; D045744:Cell Line, Tumor; D002648:Child; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005609:Free Radicals; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D012516:Osteosarcoma / Q000473:pathology*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species
chemical_list: D017304:Annexin A5; D005609:Free Radicals; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide