title: Genotoxicity and reactive oxygen species production induced by magnetite nanoparticles in mammalian cells.
abstract: We examined the genotoxicity of magnetite nanoparticles (primary particle size: 10 nm) on human A549 and Chinese hamster ovary (CHO) AA8 cells. Six hours' treatment with the particles dose-dependently increased the frequency of micronuclei (MN) in the A549 and CHO AA8 cells up to 5.2% and 5.0% at a dose of 200 µg/ml (34 µg/cm²), respectively. In A549 cells, treatment with the nano-particles (2 µg/ml) for 1 hr induced H2AX phosphorylation, which is suggestive of DNA double strand breaks (DSB). Treating CHO AA8 cells with 2 µg/ml (0.34 µg/cm²) magnetite for 1 hour resulted in a five times higher frequency of sister chromatid exchange (SCE) than the control level. We detected reactive oxygen species (ROS) in CHO cells treated with the particles. These findings indicate that magnetite nano-particles induce ROS in mammalian cells, leading to the direct or indirect induction of DSB, followed by clastogenic events including MN and SCE.
authors.affiliation: Graduate School of Science and Radiation Research Center, Osaka Prefecture University, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kawanishi
authors.forename: Sayaka
authors.initials: S
authors.lastname: Ogo
authors.forename: Miho
authors.initials: M
authors.lastname: Ikemoto
authors.forename: Yukari
authors.initials: Y
authors.lastname: Totsuka
authors.forename: Kousuke
authors.initials: K
authors.lastname: Ishino
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yagi
mesh_terms: D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D003287:Contrast Media / Q000633:toxicity*; D006224:Cricetinae; D003412:Cricetulus; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006657:Histones / Q000378:metabolism; D006801:Humans; D058185:Magnetite Nanoparticles / Q000633:toxicity*; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects*; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D013997:Time Factors
chemical_list: D003287:Contrast Media; C468783:H2AX protein, human; D006657:Histones; D058185:Magnetite Nanoparticles; D017382:Reactive Oxygen Species