PI3K活性化腫瘍は,食事制限に抵抗性がある
Nada Y Kalaany1, David M Sabatini
1Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA.
Nature
|March 13, 2009
まとめ
食事制限は腫瘍の成長に影響しますが,抵抗はフォスファティディル・イノシトール-3-キナーゼ (PI3K) 経路と関連しています. PI3Kの活性化変異により,腫瘍は食事制限に耐性を持ち,標的型療法が示唆される.
科学分野:
- 腫瘍学 腫瘍学
- メタボリック経路は
- がん生物学 がん生物学
背景:
- ダイエット制限 (DR) は,腫瘍発生を遅らせ,腫瘍の成長を遅らせることが知られている.
- 腫瘍の感受性やDRに対する耐性の根本的なメカニズムは完全に理解されていません.
研究 の 目的:
- 食事制限に対する癌細胞の感受性を決定する分子メカニズムを調査する.
- DR.の成長抑制効果に対する耐性を付与する特定の経路を特定する.
主な方法:
- マウスにおける腫瘍異種移植として培育されたヒトがん細胞系を利用した.
- PI3K経路の活性化が異なる細胞系における腫瘍の成長とDRに対する感受性を比較した.
- 遺伝子組み換えがん細胞はPI3K経路の活性 (例えば,変異したPI3Kをワイルドタイプに置き換え,PTEN発現を回復) を変化させる.
- 前立腺がんのPTEN-nullマウスモデルと構成PI3Kシグナリングが欠けている肺がんモデルで評価されたDR効果.
主要な成果:
- 構成的に活性化されたフォスファディチリノシトール-3キナーゼ (PI3K) 経路を有するがん細胞系は,DRの抗成長効果に対する抵抗を示した.
- これらの抵抗性細胞は,インスリンまたはインスリン類似成長因子1とは無関係に増殖する可能性があります.
- ワイルドタイプのPI3KまたはPTEN発現を再生することで,DRに敏感なフェノタイプに耐性腫瘍を変換しました.
- DRはPTEN-null前立腺がんの成長に影響を与えなかったが,PI3K独立の肺がんモデルでは腫瘍負担を軽減した.
結論:
- PI3K経路は,食事制限に対する腫瘍感受性の決定的な決定因子です.
- PI3K経路の活性化変異は,DRに対する耐性を授与する.
- これらの発見は,PI3K経路の活性化状態がDR-ミメティック療法に対するがんの反応を予測することを示唆しています.
関連する概念動画
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Inhibition of Cdk Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Adaptive Mechanisms in Cancer Cells
Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer.
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...

