title: Patulin-induced oxidative DNA damage and p53 modulation in HepG2 cells.
abstract: Patulin (PAT) is a mycotoxin produced by certain species of Penicillium and Aspergillus. The aim of this study was to assess PAT-induced DNA damage and to clarify the mechanisms, using human hepatoma G2 (HepG2) cells. PAT caused significant increase of DNA migration in single cell gel electrophoresis assay. To elucidate the role of glutathione (GSH), the intracellular GSH level was modulated by pre-treatment with buthionine-(S, R)-sulfoximine, a specific GSH synthesis inhibitor. It was observed that PAT significantly induced DNA damage in GSH-depleted HepG2 cells at lower concentrations. PAT induced the increased levels of reactive oxygen species and depletion of GSH in HepG2 cells using 2,7-dichlorofluorescein diacetate and 0-phthalaldehyde, respectively. PAT significantly increased the levels of 8-hydroxydeoxyguanosine and thiobarbituric acid-reactive substances in HepG2 cells. Also, PAT-induced p53 protein accumulation was observed in HepG2 cells, suggesting that the activation of p53 appeared to have been a downstream response to the PAT-induced DNA damage. These results demonstrate that PAT causes DNA strand breaks in HepG2 cells, probably through oxidative stress. Both GSH, as a main intracellular antioxidant, and p53 protein are responsible for cellular defense against PAT-induced DNA damage.
authors.affiliation: Department of Toxicology, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian 116044, Liaoning, China.
authors.forename: Si-min
authors.initials: SM
authors.lastname: Zhou
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Jiang
authors.forename: Cheng-yan
authors.initials: CY
authors.lastname: Geng
authors.forename: Jun
authors.initials: J
authors.lastname: Cao
authors.forename: Lai-fu
authors.initials: LF
authors.lastname: Zhong
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D015153:Blotting, Western; D045744:Cell Line, Tumor; D020552:Comet Assay; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005452:Fluoresceins; D005456:Fluorescent Dyes; D016158:Genes, p53 / Q000187:drug effects*; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000502:physiology; D006801:Humans; D007124:Immunoenzyme Techniques; D015227:Lipid Peroxidation / Q000187:drug effects; D009153:Mutagens / Q000633:toxicity*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010365:Patulin / Q000633:toxicity*; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; D009153:Mutagens; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; C037631:2',7'-dichlorofluorescein; D000080242:8-Hydroxy-2'-Deoxyguanosine; D010365:Patulin; D003849:Deoxyguanosine; D005978:Glutathione