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DNMT1とDNMT3bは,ヒトがん細胞の遺伝子を沈黙させるために協力しています
Ina Rhee1, Kurtis E Bachman, Ben Ho Park
1The Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
Nature
|April 5, 2002
まとめ
人間の癌細胞は,DNAメチルトランスフェラーゼ1 (DNMT1) とDNMT3Bという2つの重要な酵素に依存し,DNAメチル化と遺伝子サイレンスを行う. 両方への干渉はメチル化を大幅に低下させ,癌細胞の成長に影響を与えます.
科学分野:
- エピジェネティクス エピジェネティクス
- がん生物学 がん生物学
- 分子遺伝学 分子遺伝学
背景:
- 腫瘍抑制遺伝子の不活性化は,がんの発症において決定的に重要であり,しばしば,ハイパーメチル化を介して表遺伝子の静止を介して行われる.
- 人間の細胞における局所特異的および全局的なDNAメチル化のメカニズムは完全に理解されていません.
- Dnmt1がマウスの主体である一方で,DNMT1が欠けているヒトの癌細胞は,メチル化が著しく残っている.
研究 の 目的:
- DNMT1とDNMT3Bがヒトがん細胞におけるDNAメチル化と遺伝子静止の維持における役割を調査する.
- ゲノムメチレーションと癌細胞増殖に対するDNMT1とDNMT3Bの結合障害の影響を決定する.
主な方法:
- 結腸直腸がん細胞系におけるヒトDNMT3B遺伝子の破壊.
- DNMT1とDNMT3Bの両方の遺伝的破壊.
- グローバルDNAメチル化レベル,繰り返し配列,IGF2インプリント,p16INK4aサイレンシング,細胞成長の評価.
主要な成果:
- DNMT3Bを単独で破壊することは,全DNAメチル化に最小限の影響を及ぼしました (<3%).
- DNMT1とDNMT3Bを同時に破壊すると,メチルトランスフェラーゼの活性がほぼ排除され,ゲノムメチル化が95%以上減少しました.
- これにより,繰り返し配列の脱メチル化,IGF2インプリントの喪失,p16INK4aの再活性化,および癌細胞の成長を抑制しました.
結論:
- 2つのDNAメチルトランスファーゼ,DNMT1とDNMT3Bは,ヒトがん細胞におけるDNAメチル化と遺伝子静止を協力して維持する.
- DNAメチル化は,腫瘍細胞の最適な増殖に不可欠です.
- これらの酵素をターゲットにすることで,がん治療の治療戦略を提供することができる.
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