Host: The Japan Radiation Research Society
Histone H2X is phosphorylated by ATM with Mre11/Rad50/Nbs1 complex at DNA double strand breaks (DSB). The phosphorylated H2AX (gamma H2AX) foci are thought to be a marker of DSB caused by radiation. However, recent research has revealed that nonDSB-causing chemicals and UV also make gamma H2AX foci, suggesting the presence of multi-pathways of H2AX phosphorylation. A purpose of our study is to elucidate what environmental chemicals induce gamma H2AX foci and to classify the chemicals by H2AX phosphorylation pathways. Among the atmospheric polycyclic aromatic hydrocarbons, benzo(a)pyrene, 1,8-dinitropyrene and 3-methylchoranthrene efficiently induce gamma H2AX foci but 1-nitropyrene and 3-nitrobenzanthrone do not. Well correlation among chemical structure, cytotoxicity and gamma H2AX inducibility was not observed so far. In this presentation, I will also show the correlation among DNA damage type, cell cycle and H2AX inducibility.
