The low dose effects of human mammary epithelial cells induced by internal exposure to low radioactive tritiated water. (December 2019)

• Record Type: Journal Article
• Authors: Quan, Yi; Zhou, Caijie; Deng, Bing; Lin, Jinxian
• Is Part Of: Toxicology in vitro. Volume 61(2019)
• Publication Date: 2019-12
• Subjects: Tritium -- Low dose rate irradiation -- Complex DNA damage -- Protective effects -- Bystander effects; Toxicity testing -- In vitro -- Periodicals; Toxicology -- Periodicals; 615.9
• DOI: 10.1016/j.tiv.2019.104608
• Languages: English
• ISSNs: 0887-2333

Abstract

Abstract: Tritium is an important radioactive waste which needs to be monitored for radiation protection. Due to long biological half-life of organically bound tritium (OBT), the adverse consequence caused by chronic exposure of tritiated water (HTO) attracts concern. In this study, fibroblast cells were exposed to 2 × 10 6 Bq/ml HTO to investigate the cellular behaviors. The dose relationship of survival fraction and γH2AX foci was a "U-shaped" curve. And the results of γH2AX intensity produced by ICCM, which was obtained from different doses, demonstrated bystander signal accounted for the protective effects induced by intermediate dose of 100 mGy. The comparison of temporal kinetics and spatial dynamics of DNA repair between tritium β-rays and γ-rays showed longer time was need for the dephosphorylation of H2AX protein after HTO exposure. It indicated complex cluster DSBs induced by tritium β-rays at the low dose impaired efficient recovery of DNA damage, which bear responsibility for the persistence of residual foci after low dose expsoure. It suggests after exposed to low dose radiation cells prefer to eliminate damage population to avoid DNA damage increasing the mutation potential. Highlights: Distinct cellular behaviors were found after exposure to low dose rate tritium β-rays at low and intermediate dose. Bystander signals were involved with the protective effect observed at intermediate dose. Complex DNA damage bears responsibility for the persistence of residual γH2AX foci produced by low dose.