酸化物質によって媒介されるミトゲンシグナル伝達は,Ras変異した線維芽細胞のRas変異した線維芽細胞で媒介される
1Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
まとめ
構成的に活性なH-RasV12は細胞を変容させ,超酸化物のような反応性酸素種 (ROS) を増加させます. Ras経路,フラボタンパク質,Rac1を標的とした抗酸化物質と阻害剤は,ROSと細胞成長を抑制し,Ras誘発の変容におけるROSの媒介を示唆した.
科学分野:
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
- 腫瘍学 腫瘍学
背景:
- Rasタンパク質は,細胞シグナル伝達経路の重要な調節体です.
- 異常なRasシグナル伝達は,様々ながんに絡んでいる.
- 反応性酸素種 (ROS) は,細胞の増殖と変容において複雑な役割を果たします.
研究 の 目的:
- H-RasV12誘発の線維細胞変異における活性酸素種 (ROS) の役割を調査する.
- H-RasV12.12のダウンストリームROS生成に関与するシグナル伝達経路を特定する.
- Ras駆動がんに対する治療戦略として,ROS経路を標的とする可能性を調査する.
主な方法:
- NIH 3T3ファイブロブラストは,H-RasV12.12で安定的に変異した.
- スーパー酸化物 (.O2-) の生成を測定した.
- 支配的な陰性RasおよびRac1同型が発現した.
- 細胞は,ファルネシルトランスフェラーゼ阻害剤とディフェニレンヨドニウムで治療した.
- N-アセチル-L-システインの治療後にミトジェニック活性が評価されました.
- ミトゲン活性化タンパク質キナーゼ (MAPK) とc-Jun N-ターミナルキナーゼ (JNK) の活動が分析されました.
主要な成果:
- H-RasV12で変異した細胞は,スーパー酸化物 (.O2-) の生成が著しく増加したことを示した.
- .O2の生成は,支配的陰性Ras/Rac1,ファルネシルトランスフェラーゼ阻害剤,およびディフェニレンヨドニウムによって減少した.
- 抗酸化剤治療 (N-アセチル-L-システイン) は,H-RasV12細胞のミトジェニック活動を抑制しました.
- MAPKの活性が低下し,H-RasV12変異細胞ではJNKが活性化されませんでした.
結論:
- H-RasV12誘発の細胞変容は,ROSの生産,特に超酸化物 (.O2-) の増加と関連しています.
- Rac1とフラボタンパク質依存の経路は,H-RasV12媒介のROS生成に関与しています.
- Ras誘発細胞サイクル進行は,MAPKとJNK経路とは独立してROSによって媒介され,Ras誘発がんの新たな治療標的を示唆する可能性がある.
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