title: Evaluation of chemical phototoxicity, focusing on phosphorylated histone H2AX.
abstract: Histone H2AX is a minor component of nuclear histone H2A. The phosphorylation of histone H2AX at Ser 139, termed γ-H2AX, was originally identified as an early event after the direct formation of DNA double-strand breaks (DSBs) by ionizing radiation. Now, the generation of γ-H2AX is also considered to occur in association with secondarily formed DSBs by cellular processing such as DNA replication and repair at the site of the initial damage, including DNA adducts, crosslinks, and UV-induced photolesions. Therefore, γ-H2AX is currently attracting attention as a new biomarker for detecting various genotoxic insults. We have determined the toxic impact of various environmental stresses such as chemicals, light and/or their coexposure using γ-H2AX, and found that the γ-H2AX assay exhibited high sensitivity and a low false-positive rate as a detection system of genotoxic potential. In this review, we introduced our recent findings concerning the evaluation of chemical phototoxicity, focusing on γ-H2AX.
authors.affiliation: Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan ibuki@u-shizuoka-ken.ac.jp.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ibuki
authors.affiliation: Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Toyooka
mesh_terms: D000818:Animals; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D017484:Dermatitis, Phototoxic / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism*; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009152:Mutagenicity Tests / Q000379:methods*; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects
chemical_list: C468783:H2AX protein, human; D006657:Histones
keywords: DNA damage; chemicals; light; phototoxicity; γ-H2AX