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Increase of the RBE with LET after Irradiation of Charged Particle Beams Causes by Misrepair of DNA Double Strand Breaks
https://repo.qst.go.jp/records/59479
https://repo.qst.go.jp/records/59479aa00f6da-e6b6-4f34-9c68-44be3209b7d5
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2002-12-16 | |||||
| タイトル | ||||||
| タイトル | Increase of the RBE with LET after Irradiation of Charged Particle Beams Causes by Misrepair of DNA Double Strand Breaks | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Furusawa, Yoshiya
× Furusawa, Yoshiya× Aoki, Mizuho× Utsumi, Hiroshi× Takata, Minoru× Ando, Koichi× 古澤 佳也× 青木 瑞穂× 内海 博司× 安藤 興一 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | It is widely recognized that most radiation-induced biological endpoints are determined by the consequence of the repair of DNA double-strand breaks (dsb). Despite a large amount of molecular studies, the exact mechanisms underlying DNA repair and its fidelity are not known and remain to be elucidated. Recently, a series of DNA dsb repair gene knockout chicken cell-lines (DT40) were established. In the research work described in this paper, we examined the survival curves of the following DT40 lines: ku70-/- (NHEJ; non-homologous end-joining deficient), rad54-/- (HR; homologous recombination deficient), ku70-/-rad54-/- (double deficient), and wild-type DT40 cells. These repair-deficient cell lines were exposed to X-rays and different heavy charged particle beams accelerated with the HIMAC accelerator in Chiba, Japan, covering a LET range 2 - 800 keV/um. The ku70-/-rad54-/- strain showed the highest radiosensitivity (D10 = 0.68 Gy for X-rays) followed by the rad54-/- strain (2.3 Gy), and subsequently the wild type strain (4.2 Gy). The ku70-/- strain showed a bi-phasic survival curve. At low doses, the survival curve was similar to that of the ku70-/-rad54-/- double-knockout strain. At high dose the curve displayed a pronounced shoulder, reflecting radioresistance at a level even higher than the wild type strain. The RBEs for the repair sufficient strains (ku70-/- strain at late-S/G2 phase, rad54-/-, and wild strains) showed a typical LET dependence, i.e., RBE increased with LET, showed a peak at around 200 keV/um, and then decreased. However, the RBE for the repair deficient strains (ku70-/- strain at G1/early-S phase and ku70-/-rad54-/- strain) was approximately constant up to an LET value arond 100 keV/um, and decreased at higher LET values. The lack of increase at low-LET is probably caused by the inhability to repair, and misrepair, the DNA damage, whereas the decrease of RBE at higher LET is caused by the decrease of ion hit probability. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The First International Symposium on Ion Beams: Biological Effects and Molecular Mechanisms | |||||
| 発表年月日 | ||||||
| 日付 | 2002-08-03 | |||||
| 日付タイプ | Issued | |||||
