title: Induction of micronuclei and alteration of gene expression by an organomodified clay in HepG2 cells.
abstract: Clay2 is an organomodified montmorillonite developed by the Technological Institute of Packaging, Transport and Logistic (ITENE) in order to improve polymeric materials used in food packaging. There is not much known on Clay2 toxic potential, particularly at DNA level, therefore it is mandatory to assess its toxicity prior to its commercialization. In the present study the human hepatoma cell line (HepG2) was exposed to non-cytotoxic concentrations of Clay2 and the genomic stability was studied with the Cytokinesis block micronucleus cytome assay, by determining the formation of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs). Moreover, the expression of various genes involved in the mechanisms of its action using the real-time quantitative PCR was studied. The results obtained provide the evidence that Clay2 is potentially genotoxic as it increased the frequency of micronuclei. In addition it deregulated genes involved in the metabolism, immediate-early response/signaling, DNA damage and oxidative stress showing new valuable information on the cellular response to Clay2. Nonetheless, further studies are highly needed to elucidate the molecular mechanisms of clays toxicity.
authors.affiliation: Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González n°2, 41012 Seville, Spain. Electronic address: saramh@us.es.
authors.forename: Sara
authors.initials: S
authors.lastname: Maisanaba
authors.affiliation: National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Klara
authors.initials: K
authors.lastname: Hercog
authors.affiliation: Area of Packaging Materials and Systems, ITENE, C/Albert Einstein 1, 46980 Paterna, Valencia, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Ortuño
authors.affiliation: Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González n°2, 41012 Seville, Spain.
authors.forename: Ángeles
authors.initials: Á
authors.lastname: Jos
authors.affiliation: National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Bojana
authors.initials: B
authors.lastname: Žegura
mesh_terms: D000538:Aluminum Silicates / Q000633:toxicity*; D001546:Bentonite / Q000633:toxicity*; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D002467:Cell Nucleus; D000077215:Clay; D004249:DNA Damage; D018857:Food Packaging / Q000379:methods*; D015870:Gene Expression / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D015162:Micronucleus Tests / Q000379:methods*; D009153:Mutagens / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000538:Aluminum Silicates; D017874:Immediate-Early Proteins; D009153:Mutagens; D001546:Bentonite; D000077215:Clay
keywords: Cytokinesis block micronucleus assay; HepG2; Modified clay; Real-time quantitative PCR