腫瘍性Nrasは,持続的に競争力を高める幹細胞にバイモダルの影響を及ぼします
Qing Li1, Natacha Bohin1, Tiffany Wen1
1Department of Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA.
Nature
|November 29, 2013
まとめ
NRAS変異の活性化により,血造性幹細胞 (HSC) の増殖と自己再生が促進される. これはバイモダルメカニズムを通じて発生し,稀に分裂する変異性HSCは正常なHSCを上回り,白血病前拡大を促します.
科学分野:
- 血液学 ヘマトロジ
- 癌生物学 癌生物学について
- 幹細胞生物学 幹細胞生物学
背景:
- 血液形成性幹細胞 (HSC) の白血病前変異は,自己再生と競争力を高めることでクローン拡張を推進すると考えられています.
- しかし,HSCの増殖を増加させる突然変異は,しばしば競争力を低下させ,突然変異したHSCが野生型のHSCを凌駕する方法を理解する上でパラドックスを引き起こします.
研究 の 目的:
- NRAS (Nras(G12D)) の活性化変異が,白血病の発症前に,HSCの増殖,自己更新,および競争力をどのように影響するか調査する.
- Nras (G12D) が強化されたHSC機能を付与する根本的なメカニズムを解明する.
主な方法:
- HSCの再構成と自己再生の可能性を評価するために,放射線を受けたマウスの連続移植を活用しました.
- H2B-GFPのラベル保持と5-ブロモデオキシユリジン (BrdU) の組み込みを用いて,細胞サイクル運動を分析した.
- HSCサブセットにおけるSTAT5信号と転写応答の役割を調査した.
主要な成果:
- 腫瘍性Nras ((G12D) の単一のアレルは,HSCの増殖を増加させ,多力性祖先に長期的な自己再生の可能性を与えました.
- Nras ((G12D) は,HSCにバイモダルの効果を示し,一部はより頻繁に,一部はより頻繁に分裂した.
- 稀に分裂するNras ((G12D) HSCは,野生型のHSCと比較して優れた競争力のある再生能力を示したが,頻繁に分裂するHSCはそうではなかった.
- Nras ((G12D) はSTAT5シグナル伝達を促進し,異なるHSCサブセットで異なる転写応答をもたらしました.
結論:
- Nras ((G12D) 変異を活性化することで,単一の腫瘍発生性アレルを通して,HSCの増殖,競争力,自己再生を高めることができます.
- HSCの遺伝子発現,細胞サイクル,再構成の可能性に対する双方向効果は,Nras (((G12D)) が白血病前クローンの拡大をどのように駆動するかを説明します.
- STAT5シグナリングは,HSCに対するNrasの文脈依存的な影響 (G12D) を媒介する上で重要な役割を果たします.
関連する概念動画
Cancer Stem Cells and Tumor Maintenance
4.3K
Early diagnosis and treatment can often cure cancer. However, even with treatment, residual cells called cancer stem cells (CSC) might remain, often causing tumor recurrence. These cancer stem cells possess the potential for self-renewal and multi-lineage differentiation and are often responsible for the therapeutic resistance displayed in most cancers.
Cancer stem cells are thought to originate from tissue-specific normal stem cells or progenitor cells. The normal stem cells usually reside in...
Cancer stem cells are thought to originate from tissue-specific normal stem cells or progenitor cells. The normal stem cells usually reside in...
4.3K
Cancer Stem Cells and Tumor Maintenance
2.0K
2.0K
Abnormal Proliferation
4.0K
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...
4.0K
The Ras Gene
5.7K
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a...
Ras is a...
5.7K
Cancer-Critical Genes I: Proto-oncogenes
9.2K
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
9.2K
Adaptive Mechanisms in Cancer Cells
5.8K
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,...
5.8K


