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Heavy ion-induced mammary carcinogenesis in four rat strains
https://repo.qst.go.jp/records/68539
https://repo.qst.go.jp/records/685396493df17-fddb-4492-b7d5-3f6c8ab48068
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-06-26 | |||||
| タイトル | ||||||
| タイトル | Heavy ion-induced mammary carcinogenesis in four rat strains | |||||
| 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 output | |||||
| 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 |
Imaoka, Tatsuhiko
× Imaoka, Tatsuhiko× Nishimura, Mayumi× Nagai, Junya× Kakinuma, Shizuko× Shimada, Yoshiya× 今岡 達彦× 西村 まゆみ× 永井 絢也× 柿沼 志津子× 島田 義也 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Background – Investigation of heavy ion-induced carcinogenesis is important for risk estimation of both heavy-ion therapy and cosmic radiation exposure. It is concerned that high-energy heavy ion particles in the galactic cosmic rays may enhance the probability of cancer in astronauts. It is now generally accepted that exposure of the human female breast to ionizing radiation will increase the risk of breast cancer. Animal studies have proven that relative biological effectiveness of neutron, one of high LET radiation, is extremely high, and that mammary tumor susceptibility is under a strong influence of genetic factors. Therefore, it is important to gain basic information on heavy ion-induced mammary carcinogenesis. \nExperiment – Using HIMAC, a heavy ion synchrotron at NIRS, we irradiated 8-week-old female virgin rats of four strains (ACI/N, F344, Sprague-Dawley (SD) and Wistar) with 290 MeV carbon beam at doses of 0, 0.5, 1 and 2 Gy. We then examined mammary tumor development up to 300 days by palpation. At autopsy, mammary tumors were counted and collected for pathological examination and molecular analysis for H-ras1 gene mutation. \nResult – We found that there was a distinct strain difference in response to carbon beam-induced mammary carcinogenesis; the susceptibility was high in Sprague-Dawley, intermediate in Wistar, and low in F344 and ACI/N rats, and that irradiation shortened the tumor latency in dose-dependent manners. The incidence and multiplicity of tumors at autopsy showed similar tendencies. Pathologically, tumors were mainly adenocarcinomas and fibroadenomas. Mutations in the codon 12 of H-ras1 gene, which are frequently seen in chemically induced mammary tumors, were not found at all. \nConclusion – Heavy ions induce malignant mammary tumors to rats in a dose-dependent manner at doses between 0.5 and 2 Gy. This induction was also influenced by genetic factors of the rat. |
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| 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 | 12th International Congress of Radiation Research | |||||
| 発表年月日 | ||||||
| 日付 | 2003-08-22 | |||||
| 日付タイプ | Issued | |||||
