Related Experiment Video
Updated: Jun 20, 2026

Preparation of Peripheral Blood Mononuclear Cell Pellets and Plasma from a Single Blood Draw at Clinical Trial Sites for Biomarker Analysis
Published on: March 20, 2021
ATM-dependent hyper-radiosensitivity in mammalian cells irradiated by heavy ions
Lian Xue1, Dong Yu, Yoshiya Furusawa
1School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou, China.
Purpose:
Low-dose hyper-radiosensitivity (HRS) and the later appearing radioresistance (termed induced radioresistance [IRR]) was mainly studied in low linear energy transfer (LET) radiation with survival observation. The aim of this study was to find out whether equivalent hypersensitivity occurred in high LET radiation, and the roles of ataxia telangiectasia mutated (ATM) kinase.
Methods And Materials:
Survival and mutation were measured by clonogenic assay and HPRT mutation assay. ATM Ser1981 activation was detected by Western blotting and immunofluorescent staining. Pretreatment of specific ATM inhibitor (10 microM KU55933) and activator (20 microg/mL chloroquine) before carbon radiation were adopted to explore the involvement of ATM. The roles of ATM were also investigated in its G2/M checkpoint function with histone H3 phosphorylation analysis and flow cytometric assay, and DNA double strand break (DSB) repair function measured using gamma-H2AX foci assay.
Results:
HRS/IRR was observed with survival and mutation in normal human skin fibroblast cells by carbon ions, while impaired in cells with intrinsic ATM deficiency or normal cells modified with specific ATM activator or inhibitor before irradiation. The dose-response pattern of ATM kinase activation was concordant with the transition from HRS to IRR. The ATM-dependent "early" G2 checkpoint arrest and DNA DSB repair efficiency could explain the difference between HRS and IRR.
Conclusions:
These data demonstrate that the HRS/IRR by carbon ion radiation is an ATM-dependent phenomenon in the cellular response to DNA damage.
More Related Videos
Related Concept Videos
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Biological Effects of Radiation
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
Adaptive Mechanisms in Cancer Cells
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
DNA Damage can Stall the Cell Cycle

