B細胞の拡散型大細胞リンパ腫における複数のプロトオンコゲンの高変異
L Pasqualucci1, P Neumeister, T Goossens
1Institute for Cancer Genetics and the Department of Pathology, Columbia University, New York, New York 10032, USA.
Nature
|July 19, 2001
まとめ
異常な超変異活動は,拡散型大細胞リンパ腫 (DLCL) の重要な遺伝子を標的とし,ゲノム全体の不安定性を引き起こします. ソマティック・ハイパーミューテーションのこの機能不全は,これらの生殖中心から派生した腫瘍におけるリンパマゲネシスに大きく寄与している可能性があります.
科学分野:
- 腫瘍学 腫瘍学
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
背景:
- ゲノム不安定性は癌の特徴であり,欠陥染色体分離やDNA不一致修復などのメカニズムを通じて腫瘍発生に寄与する.
- B細胞リンパ腫はしばしば染色体転位を示すが,リンパ変異の過程における全ゲノム不安定の根本的なメカニズムは不明である.
- ソマティック・ハイパーミューテーションは,通常,B細胞発達の過程で生殖中心のB細胞の免疫グロブリン変数 (V) 領域の遺伝子で発生する.
研究 の 目的:
- 拡散型大細胞リンパ腫 (DLCL) の全ゲノム不安定性のメカニズムを調査する.
- リンパマゲネシスに寄与する体性高変異過程における潜在的な機能障害を特定する.
- DLCLsにおける異常ハイパーミューテーションと染色体トランスロケーションの関係を探求する.
主な方法:
- DLCLサンプルにおけるプロトオンコゲン (PIM1,MYC,RhoH/TTF,PAX5) の変異パターンの分析.
- DLCLにおける突然変異プロファイルの比較と,正常生殖中心のB細胞および他のリンパ腫における突然変異プロファイルの比較.
- ハイパーミューテーションサイトと染色体転位ブレイクポイントの関係に関する評価.
主要な成果:
- 異常な超変異活動は,DLCLの50%以上で特定され,複数の原発がん基因を標的とした.
- これらの変異は,V領域ハイパーミューテーションとは異なり,正常な生殖細胞中心のB細胞または他の生殖細胞中心由来リンパ腫では見つかりませんでした.
- 影響を受けた遺伝子は,同じ領域の染色体転位に敏感であり,ハイパーミューテーションが転位につながる二重鎖の断裂を生成することを示唆しています.
結論:
- プロトオンコゲンを含む複数の遺伝子ローシを標的にするソマティックハイパーミューテーションの機能障害は,DLCLsと関連しています.
- この異常な超変異プロセスは,重要な遺伝子を変異させ,染色体の転位を誘発する可能性があるため,リンパ変異の重要な原動力である可能性があります.
- この発見は,拡散型大細胞リンパ腫で観察されるゲノム不安定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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