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Updated: Aug 29, 2025

Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
THE ROLE OF DNA DOUBLE-STRAND BREAK REPAIR THROUGH NON-HOMOLOGOUS END JOINING IN THE DOSE-RATE EFFECT IN TERMS OF
Hisayo Tsuchiya1, Mikio Shimada1, Kaima Tsukada1
1Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
Abstract:
It is generally and widely accepted that the biological effects of a given dose of ionizing radiation, especially those of low linear energy transfer radiations like X-ray and gamma ray, become smaller as the dose rate becomes lower. This phenomenon, known as 'dose-rate effect (DRE),' is considered due to the repair of sublethal damage during irradiation but the precise mechanisms for DRE have remained to be clarified. We recently showed that DRE in terms of clonogenic cell survival is diminished or even inversed in rodent cells lacking Ku, which is one of the essential factors in the repair of DNA double-strand breaks (DSBs) through non-homologous end joining (NHEJ). Here we review and discuss the involvement of NHEJ in DRE, which has potential implications in radiological protection and cancer therapeutics.
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