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Updated: Jun 2, 2025

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Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
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体細胞における突然変異性DNA病変の長期持続
Michael Spencer Chapman1,2, Emily Mitchell1,3,4, Kenichi Yoshida1
1Wellcome Sanger Institute, Hinxton, UK.
Nature
|January 15, 2025
まとめ
ヒトの幹細胞に長年存在し,突然変異に大きく貢献するDNAの損傷もあります. 内外の要因による DNAの持続的な損傷は 細胞変異率に影響を与え 血液がんと関連しています
科学分野:
- 遺伝学
- 分子生物学
- 癌 研究
背景:
- DNAの損傷は細胞の中で常にあり ほとんどの損傷はすぐに修復されます
- 人間の幹細胞におけるDNA損傷の長期的持続性はよく理解されていません.
研究 の 目的:
- ヒト幹細胞の複数の細胞サイクルにわたる DNA 損傷の持続性を調査する.
- 持続的なDNA病変の起源と変異の影響を特徴づけるため
主な方法:
- 89人のドナーからの高解像度の系統樹の分析
- 血液,肝臓,気管幹細胞の持続的なDNA損傷から生じる変異の特定.
- 持続的な病変に関連した変異シグネチャの特徴
主要な成果:
- 正常なヒト幹細胞の細胞サイクルを通して 818のDNA病変を特定しました.
- 持続的な病変は,たばこや化学療法を受けたドナーでより頻繁に見られ,外因的な起源を示しています.
- 血液形成性幹細胞では,持続的な病変 (おそらく内生性) が着実に発生し,長年にわたって持続し,SBS19の変異シグネチャーに寄与しました.
- 造血幹細胞ごとに推定8つの持続的な病変があり,その半数は毎週変異を引き起こします.
- 血液細胞の変異の16%と,同様の割合の血液がんの原動力変異は,SBS19シグネチャーに関連しています.
結論:
- ヒトの幹細胞に数ヶ月から数年間も存在します
- 内在的および外在的な源からのこれらの持続的な病変は,体細胞における全体的な変異負荷に大きく寄与する.
- SBS19の変異シグネチャーは,持続的なDNA病変と関連しており,血液細胞と血液がんに多く見られます.
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