複製フォークの安定性は,BRCA欠乏細胞に化学抵抗性を与える
Arnab Ray Chaudhuri1, Elsa Callen1, Xia Ding2
1Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Nature
|July 23, 2016
まとめ
PTIPタンパク質の喪失は,複製フォークの分解を防ぐことによって,Brca1/ 2遺伝子が欠けているがん細胞をDNA損傷から保護します. この発見はシスプラチンやPARP阻害剤のような化学療法剤に対する薬剤耐性メカニズムに関する新しい洞察を提供します.
科学分野:
- 分子生物学
- 癌 研究
- 遺伝学
背景:
- Brca1とBrca2の遺伝子が欠けている細胞は,DNAの二重鎖の修復に障害がある.
- この欠乏は,シスプラチンやポリアドプリボゼポリメラーゼ (PARP) 阻害剤などのDNAダメージを与える物質に対する過敏性につながる.
研究 の 目的:
- Brca1/2欠乏細胞におけるPTIP (MLL3/4複合体内のタンパク質) の保護作用を調査する.
- PTIP欠乏がDNAダメージを与える物質に耐性を与える根本的なメカニズムを解明する.
主な方法:
- PTIPとない Brca1/2欠乏細胞の分析
- DNAの二重鎖の断裂における同種の再結合活動の評価
- 停止した複製フォークへのMRE11核酵素の徴募の調査.
- 新生DNA鎖の分解を評価する
- Brca2欠乏性腫瘍細胞における薬剤耐性の研究
主要な成果:
- PTIPの喪失は,Brca1/ 2欠乏した細胞をDNA損傷から保護し,Brca2欠乏した胚性幹細胞の致死性を救います.
- PTIP欠乏は同種の再結合を回復させないが,停滞した複製フォークへのMRE11の採用を阻害する.
- MRE11募集の阻害は,新生DNA鎖を分解から保護し,耐性を授与します.
- 複製フォークの保護は,Brca2欠乏性腫瘍細胞におけるPARP阻害剤とシスプラチンに対する耐性に関連しています.
結論:
- PTIPは,同種の再結合修復ではなく,複製フォークによるDNA損傷からBrca1/ 2欠乏細胞を保護する上で重要な役割を果たします.
- Brca2欠乏性腫瘍における化学療法剤に対する耐性の獲得は,複製フォークの保護メカニズムによって起こる.
- PARP1とCHD4を含む様々なタンパク質の破壊は,複製フォークの保護に収束し,複雑な薬剤耐性経路を強調します.
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