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がんにおけるクラスター化変異のマッピングは,ecDNAのAPOBEC3変異を明らかにする
Erik N Bergstrom1,2,3, Jens Luebeck4,5, Mia Petljak6
1Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA.
Nature
|February 10, 2022
まとめ
この研究は2,583の癌ゲノムにおけるクラスター化した変異を包括的に分析し,様々な変異過程と癌の誘導因子と患者の生存との関係を明らかにした. APOBEC3は染色体外DNAの進化に 重要な役割を果たしています
科学分野:
- ゲノミクス
- 癌 生物学
- 変異シグネチャー
背景:
- 癌ゲノムでは,置換とインデルを含むクラスター化された体内変異が一般的です.
- 以前の研究ではオミキリやカテーギスなどの特定のタイプが特定されましたが,様々な癌の総合的な特徴はありませんでした.
研究 の 目的:
- 30種類の癌の大きなコホートで,クラスターされた置換と小さな挿入/削除 (インデル) を包括的に特徴付ける.
- 駆動遺伝子,遺伝子発現,患者の生存とのクラスター変異の関連性を調査する.
- オミキリ,カテギス,新たに特定されたキクロナを含む様々なクラスター型変異の背後にある異なった変異過程を解明する.
主な方法:
- 30種類の癌から採取した2,583個の癌の全ゲノム解析です
- クラスター化した体変異 (置換とインデル) を特定し,特徴付けるためのバイオ情報分析.
- 変異パターンをゲノム特性,遺伝子発現,生存データ,および既知の変異過程 (例えば喫煙,APOBEC3) と関連付けるための相関分析.
主要な成果:
- 群集変異はドライバー遺伝子で有意に濃縮され,異なる遺伝子発現と患者の生存率の変化と関連していました.
- クラスタ化されたインデルの複数の異なった変異過程が特定され,そのうちのいくつかは喫煙と同類再結合欠陥に関連している.
- 双塩基の置換は少なくとも12のプロセスから生じたが,多塩基の置換は主に喫煙や紫外線に関連していた.
- オミキリ事件は主にAPOBEC3に起因しましたが,APOBEC3パターンに一致したのは16. 2%のみでした.
- 76. 1%がAIDとAPOBEC3デアミナーゼに関連していた.
- APOBEC3 カタエギスとクロモソーム外DNA (ecDNA) の新種の共生は,ecDNA陽性サンプルの31%で発見されました.
- 癌の遺伝子を宿すecDNAは,がんの進化における役割を示す,ポジティブな選択とキクロニックハイパーミューテーションを示した.
結論:
- ヒトの癌は多様性のある 集団的変異プロセスを表しています
- APOBEC3の活動は,繰り返し発生する変異の重要な原動力であり,キクロナスのようなプロセスを通してecDNAの進化を助長する.
- これらのクラスタ化された変異パターンを理解することで 癌の発達と潜在的な治療戦略の洞察が得られます
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