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Evaluation of threshold and mechanisms of the combined effect of radiation and ethyl-nitrosourea
https://repo.qst.go.jp/records/61320
https://repo.qst.go.jp/records/61320e0c2146b-b59f-4ecc-b1c6-582e7ca8d5f5
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-03-31 | |||||
| タイトル | ||||||
| タイトル | Evaluation of threshold and mechanisms of the combined effect of radiation and ethyl-nitrosourea | |||||
| 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 |
Shimada, Yoshiya
× Shimada, Yoshiya× Nishimura, Mayumi× Kakinuma, Shizuko× 島田 義也× 西村 まゆみ× 柿沼 志津子 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | We are living in the environment with numerous natural and man-made radiation and chemicals. Cancer development in human, therefore, is considered as a result of interactions of these factors. It becomes clear that carcinogenic response of radiation could be influenced by these factors. The aim of this study is to elucidate the mode and mechanism of the combined effect of chemicals with radiation, especially at low or threshold dose range. The cancer models used in the current study are mouse T-cell lymphomas (TL), which develop after exposure to ionizing radiation and/or ethyl-nitrosourea (ENU). We demonstrated here that synergistic effect was obvious for pre-exposure to high dose radiation, while the effect was marginal or antagonistic for low or threshold dose radiation. When order of exposure was reversed, i.e., ENU followed by X-rays, the mode of combined exposure became additive, indicating the order of exposure plays a key role. The threshold for X-rays was not altered by subsequent-exposure to ENU, while threshold of ENU disappeared by X-ray-exposure. Molecular analysis showed that loss of heterozygosity (LOH) on chromosome 11 and Ikaros mutations were associated with X-ray-induced TL, but not ENU-induced TL. TL developed after combined treatment of X-rays followed by ENU showed molecular changes similar to ENU-induced TL, while TL after treatment of ENU followed by X-rays showed X-ray-type changes. The order is also important for determining molecular pathways of carcinogenesis. Taken together, it is concluded that the mode of combined effect is dependent upon the treatment order and dose of carcinogens. |
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| 発表年月日 | ||||||
| 日付 | 2006-03-16 | |||||
| 日付タイプ | Issued | |||||
