title: Titanium dioxide nanoparticles exhibit genotoxicity and impair DNA repair activity in A549 cells.
abstract: Titanium dioxide nanoparticles (TiO(2)-NPs) are produced in large quantities, raising concerns about their impact for human health. The aim of this study was to deeply characterize TiO(2)-NPs genotoxic potential to lung cells, and to link genotoxicity to physicochemical characteristics, e.g., size, specific surface area, crystalline phase. A549 cells were exposed to a panel of TiO(2)-NPs with diameters ranging from 12 to 140 nm, either anatase or rutile. A set of complementary techniques (comet and micronucleus assays, gamma-H2AX immunostaining, 8-oxoGuanine analysis, H2-DCFDA, glutathione content, antioxidant enzymes activities) allowed us to demonstrate that small and spherical TiO(2)-NPs, both anatase and rutile, induce single-strand breaks and oxidative lesions to DNA, together with a general oxidative stress. Additionally we show that these NPs impair cell ability to repair DNA, by inactivation of both NER and BER pathways. This study thus confirms the genotoxic potential of TiO(2)-NPs, which may preclude their mutagenicity and carcinogenicity.
authors: UMR3299 CEA-CNRS, Service Interdisciplinaire des Systèmes Moléculaires et Matériaux, Laboratoire Structure et Dynamique par Résonance Magnétique, CEA Saclay, Gif sur Yvette.
authors: Mary-Line
authors: ML
authors: Jugan
authors: Sabrina
authors: S
authors: Barillet
authors: Angelique
authors: A
authors: Simon-Deckers
authors: Nathalie
authors: N
authors: Herlin-Boime
authors: Sylvie
authors: S
authors: Sauvaigo
authors: Thierry
authors: T
authors: Douki
authors: Marie
authors: M
authors: Carriere
mesh_terms: D000704:Analysis of Variance; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D004260:DNA Repair; D006801:Humans; D015162:Micronucleus Tests; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D014025:Titanium / Q000737:chemistry / Q000633:toxicity*
chemical_list: C009495:titanium dioxide; D014025:Titanium