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遺伝子スクリーンは,PITX1をRAS活性と腫瘍発生性の抑制剤として識別します
Ingrid G M Kolfschoten1, Bart van Leeuwen, Katrien Berns
1Division of Tumor Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
Cell
|June 18, 2005
まとめ
PITX1は,RAS経路を阻害することによって,腫瘍抑制剤として作用します. 低PITX1発現は癌と相関し,それを回復すると腫瘍の成長が減り,癌の発症の新たなメカニズムが明らかになる.
科学分野:
- 腫瘍学 腫瘍学
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- RAS変異の活性化が腫瘍発生を誘発するが,多くのがんには野生型のRASがあり,代替的な活性化メカニズムを示唆する.
- 新種の腫瘍抑制遺伝子を特定することは,がんの発達を理解し,新しい治療目標を見つけるために不可欠です.
研究 の 目的:
- 癌の発生に関与する新しい腫瘍抑制遺伝子を特定する.
- RAS経路の調節と腫瘍発生におけるPITX1の役割を調査する.
主な方法:
- RNA干渉ライブラリをスキャンし,そのノックダウンが腫瘍性RASなしでヒトの原始細胞を変容させる遺伝子を検出しました.
- 人間の腫瘍およびがん細胞系におけるPITX1発現を評価した.
- 大腸がん細胞におけるPITX1発現を回復し,腫瘍発生性に対する効果を評価した.
- PITX1.1の転写標的としてRASAL1を特定しました.
主要な成果:
- PITX1を新しい腫瘍抑制遺伝子として特定しました.
- PITX1のノックダウンはRAS経路を活性化し,腫瘍発生性を促進します.
- 低PITX1発現は前立腺,膀腫瘍,および野生型RAS結腸がん細胞系において観察されました.
- PITX1の回復は,野生型のRASに依存した方法で腫瘍発生性を抑制しました.
- PITX1は,RASAL1.1の転写的調節を通じてRAS経路をダウンレギュレーションする.
結論:
- PITX1は,RASAL1.1を通じてRAS経路をダウンレギュレーションすることによって,腫瘍抑制剤として機能します.
- PITX1-RASAL1軸の調節不良は,野生型RASであるがんの腫瘍発生に寄与する可能性があります.
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