title: Different mechanisms are involved in oxidative DNA damage and genotoxicity induction by ZnO and TiO2 nanoparticles in human colon carcinoma cells.
abstract: In this work we investigated the genotoxicity of zinc oxide and titanium dioxide nanoparticles (ZnO NPs; TiO2 NPs) induced by oxidative stress on human colon carcinoma cells (Caco-2 cells). We measured free radical production in acellular conditions by Electron Paramagnetic Resonance technique and genotoxicity by micronucleus and Comet assays. Oxidative DNA damage was assessed by modified Comet assay and by measuring 8-oxodG steady state levels. The repair kinetics of DNA oxidation as well as the expression levels of hOGG1 were also analyzed. Even if both NPs were able to produce ROS in acellular conditions and to increase 8-oxodG levels in Caco-2 cells, only ZnO NPs resulted genotoxic inducing micronuclei and DNA damage. Furthermore, Caco-2 cells exposed to ZnO NPs were not able to repair the oxidative DNA damage that was efficiently repaired after TiO2 NPs treatment, through OGG1 involvement. These results indicate that the high oxidant environment caused by ZnO NPs in our cellular model can induce DNA damage and affect the repair pathways.
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zijno
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: De Angelis
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: De Berardis
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Andreoli
authors.affiliation: National Center for Chemicals, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Russo
authors.affiliation: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Pietraforte
authors.affiliation: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Scorza
authors.affiliation: S.C. Mutagenesis, IRCCS AOU San Martino, IST (Istituto Nazionale per la Ricerca sul Cancro), CBA Torre A2, L.go R. Benzi 10, Genova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Degan
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Health and Consumer Protection, Nanobiosciences Unit, Ispra, VA, Italy.
authors.forename: Jessica
authors.initials: J
authors.lastname: Ponti
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Health and Consumer Protection, Nanobiosciences Unit, Ispra, VA, Italy.
authors.forename: Francois
authors.initials: F
authors.lastname: Rossi
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, Italy. Electronic address: barone@iss.it.
authors.forename: Flavia
authors.initials: F
authors.lastname: Barone
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D018938:Caco-2 Cells; D003110:Colonic Neoplasms / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage; D045647:DNA Glycosylases / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D053758:Nanoparticles / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000633:toxicity*; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D009153:Mutagens; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D000080242:8-Hydroxy-2'-Deoxyguanosine; D014025:Titanium; D045647:DNA Glycosylases; C479058:oxoguanine glycosylase 1, human; D003849:Deoxyguanosine; D015034:Zinc Oxide
keywords: Caco-2 cells; Genotoxicity; Nanoparticles; Oxidative DNA damage; Oxidative stress