INK4/ARF局所を抑制することにより,Cdc6の腫瘍性活性が発揮される
Susana Gonzalez1, Peter Klatt, Sonia Delgado
1Tumor Suppression Group, Spanish National Cancer Research Center (CNIO), E-28029 Madrid, Spain.
Nature
|March 31, 2006
まとめ
過剰発現したCdc6は,ヘテロクロマチンを形成することによってINK4/ARF腫瘍抑制器の位置を抑制し,がんの発症を促進します. このメカニズムは,RD ((INK4/ARF) 制御要素を巻き込み,Cdc6を細胞の不死化と変異と結びつける.
科学分野:
- 腫瘍学 腫瘍学
- 分子生物学は分子生物学である.
- エピジェネティクス エピジェネティクス
背景:
- 決定的な腫瘍抑制剤 (p15INK4b,ARF,p16INK4a) をコードするINK4/ARFの位置は,ヒトの癌では頻繁に不活性化されます.
- INK4/ARFロカス発現を調節するメカニズムは,依然としてほとんど不明です.
研究 の 目的:
- INK4/ARFの位置を規制する規制メカニズムを調査する.
- 腫瘍抑制遺伝子発現の調節におけるCdc6の役割を調査する.
主な方法:
- INK4/ARFの場所でのDNA複製の起源と保存されたノンコーディング要素 (RD ((INK4/ARF)) の識別.
- RD ((INK4/ARF) のRNA干渉媒介によるヘテロクロマチニゼーションにより,その調節機能を評価する.
- Cdc6発現レベルと,INK4/ARFロカスサイレンシングと癌のフェノタイプとの相関の分析.
主要な成果:
- Cdc6,Orc2,MCMを含むマルチタンパク質複合体は,RD ((INK4/ARF) 要素内の確認された複製原点で組み合わされます.
- RD ((INK4/ARF) のヘテロクロマチニゼーションは,INK4/ARFのロクスの転写抑制につながります.
- 高レベルのCdc6は,RD ((INK4/ARF) 依存の抑制,ヒストンデセチラゼの徴募,ヘテロクロマチンの形成,INK4/ARF腫瘍抑制剤の発現の低下を誘発する.
- Cdc6過剰発現は,細胞不死化,腫瘍変異,肺がんにおけるp16INK4aレベル低下と相関しています.
結論:
- 異常なCdc6発現は,RD ((INK4/ARF) 要素経由でINK4/ARFロクスを腫瘍学的に抑制する.
- Cdc6は,エピジェネティックメカニズムを通じて腫瘍抑制遺伝子発現の新たなレギュレータとして作用します.
- この経路は,Cdc6ががんの発症に寄与する新しいメカニズムを強調しています.
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