title: The influence of non-DNA-targeted effects on carbon ion-induced low-dose hyper-radiosensitivity in MRC-5 cells.
abstract: Low-dose hyper-radiosensitivity (LDHRS) is a hot topic in normal tissue radiation protection. However, the primary causes for LDHRS still remain unclear. In this study, the impact of non-DNA-targeted effects (NTEs) on high-LET radiation-induced LDHRS was investigated. Human normal lung fibroblast MRC-5 cells were irradiated with high-LET carbon ions, and low-dose biological effects (in terms of various bio-endpoints, including colony formation, DNA damage and micronuclei formation) were detected under conditions with and without gap junctional intercellular communication (GJIC) inhibition. LDHRS was observed when the radiation dose was <0.2 Gy for all bio-endpoints under investigation, but vanished when the GJIC was suppressed. Based on the probability of cells being hit and micro-dose per cell calculation, we deduced that the LDHRS phenomenon came from the combined action of direct hits and NTEs. We concluded that GJIC definitely plays an important role in cytotoxic substance spreading in high-LET carbon ion-induced LDHRS.
authors.affiliation: Medical Physics Division, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China Department of Modern Physics, Lanzhou University, Lanzhou 730000, China University of Chinese Academy of Sciences, Beijing 100049, China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Ye
authors.affiliation: Gansu Provincial People's Hospital, Lanzhou 730000, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ning
authors.affiliation: Medical Physics Division, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Xinguo
authors.initials: X
authors.lastname: Liu
authors.affiliation: Medical Physics Division, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Modern Physics, Lanzhou University, Lanzhou 730000, China.
authors.forename: Tieshan
authors.initials: T
authors.lastname: Wang
authors.affiliation: Medical Physics Division, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China liqiang@impcas.ac.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
mesh_terms: D002244:Carbon / Q000494:pharmacology*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004247:DNA / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007477:Ions; D015162:Micronucleus Tests; D008856:Microscopy, Fluorescence; D010766:Phosphorylation / Q000528:radiation effects; D011336:Probability
chemical_list: C468783:H2AX protein, human; D006657:Histones; D007477:Ions; D002244:Carbon; D004247:DNA
keywords: carbon-ion radiation; gap junctional intercellular communication; low-dose hyper-radiosensitivity; non-DNA-targeted effect