Heat exposure enhances radiosensitivity by depressing DNA-PK kinase activity during double strand break repair
-
- Makoto Ihara
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University NagasakiJapan
-
- Satoshi Takeshita
- Joint Research Division, Center for Industry, University and Government Cooperation, Nagasaki University NagasakiJapan
-
- Kumio Okaichi
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University NagasakiJapan
-
- Yutaka Okumura
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University NagasakiJapan
-
- Takeo Ohnishi
- Department of Radiation Oncology, School of Medicine, Nara Medical University, Kashihara NaraJapan
書誌事項
- 公開日
- 2014-02-17
- 資源種別
- journal article
- DOI
-
- 10.3109/02656736.2014.887793
- 公開者
- Informa UK Limited
この論文をさがす
説明
From the role of double strand DNA dependent protein kinase (DNA-PKcs) activity of non-homologous end joining (NHEJ) repair for DNA double strand breaks (DSBs), we aim to define possible associations between thermo-sensitisation and the enzyme activities in X-ray irradiated cells.DNA-PKcs deficient mouse, Chinese hamster and human cultured cells were compared to the parental wild-type cells. The radiosensitivities, the number of DSBs and DNA-PKcs activities after heat-treatment were measured.Both DNA-PKcs deficient cells and the wild-type cells showed increased radiosensitivities after heat-treatment. The wild-type cells have two repair processes; fast repair and slow repair. In contrast, DNA-PKcs deficient cells have only the slow repair process. The fast repair component apparently disappeared by heat-treatment in the wild-type cells. In both cell types, additional heat exposure enhanced radiosensitivities. Although DNA-PKcs activity was depressed by heat, the inactivated DNA-PKcs activity recovered during an incubation at 37 °C. DSB repair efficiency was dependent on the reactivation of DNA-PKcs activity.It was suggested that NHEJ is the major process used to repair X-ray-induced DSBs and utilises DNA-PKcs activity, but homologous recombination repair provides additional secondary levels of DSB repair. The thermo-sensitisation in X-ray-irradiated cells depends on the inhibition of NHEJ repair through the depression of DNA-PKcs activities.
収録刊行物
-
- International Journal of Hyperthermia
-
International Journal of Hyperthermia 30 (2), 102-109, 2014-02-17
Informa UK Limited