title: Live cell imaging combined with high-energy single-ion microbeam.
abstract: DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10(-3) s(-1) and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10(-2) s(-1).
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Na
authors.initials: N
authors.lastname: Guo
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Guanghua
authors.initials: G
authors.lastname: Du
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Guo
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Ruqun
authors.initials: R
authors.lastname: Wu
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Junzhe
authors.initials: J
authors.lastname: Wei
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D057054:Molecular Imaging / Q000379:methods*; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human