WEKO3
アイテム
電離放射線およびメチルニトロソ尿素によるラット乳がん誘発作用の年齢依存性およびそのメカニズム
https://repo.qst.go.jp/records/69557
https://repo.qst.go.jp/records/6955702c7691e-0d9b-48db-8a46-2d908917e0ca
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2008-10-31 | |||||
| タイトル | ||||||
| タイトル | 電離放射線およびメチルニトロソ尿素によるラット乳がん誘発作用の年齢依存性およびそのメカニズム | |||||
| 言語 | ||||||
| 言語 | jpn | |||||
| 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 |
今岡, 達彦
× 今岡, 達彦× 西村, まゆみ× 島田, 義也× 今岡 達彦× 西村 まゆみ× 島田 義也 |
|||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Controversial evidence exists for whether immature mammary gland is sensitive to carcinogens. We treated pre- and postpubertal (3- and 7-week-old) female rats with γ-rays (IR, 2 Gy) or 1-methyl-1-nitrosourea (MNU; 20 mg/kg) and examined mammary cancer incidence, estrogen (ER) and progesterone receptor (PR) expression statuses, H-<i>ras</i> mutation and expression of several genes, as well as histologic changes of ovaries. Mammary cancer incidence was higher in rats with prepubertal IR exposure than postpubertal one, but the relationship was opposite for MNU. Mammary cancers after prepubertal IR exposure, which resulted in severe ovarian damages, showed ER and PR negativity and low expression of growth factor genes <i>Areg</i> and <i>Tnfsf11</i>. H-<i>ras</i> mutation was specific to MNU-induced cancers and associated with ER positivity, as predicted by the estrogen dependence of H-<i>ras</i> expression. In conclusion, prepubertal IR exposure results in lower incidence of mammary cancer probably because of insufficient tumor promotion caused by the damaged ovary, while prepubertal MNU exposure leads to high incidence and receptor positivity probably because of sufficient tumor promotion by the functional ovary. | |||||
| 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 | 第67回日本癌学会学術総会 | |||||
| 発表年月日 | ||||||
| 日付 | 2008-10-30 | |||||
| 日付タイプ | Issued | |||||
