Severe hypoxia defines heterogeneity and selects highly immature progenitors within clonal erythroleukemia cells
Severe hypoxia defines heterogeneity and selects highly immature progenitors within clonal erythroleukemia cells
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DOI：
10.1634/stemcells.2006-0637
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发表时间：
2007-01-01
期刊：
影响因子：
5.2
通讯作者：
Dello Sbarba, Persio
中科院分区：
文献类型：
--
作者：
Giuntoli, Serena;Rovida, Elisabetta;Dello Sbarba, Persio
我们发现，对严重缺氧的抵抗定义了正常造血群体中的等级水平，缺氧调节了祖细胞生成和造血干细胞（HSC）维持之间的平衡，有利于后者。本研究涉及缺氧（0.1%的氧气）在体外对朋友的小鼠红白血病（MEL）细胞的影响，解决的问题是否克隆白血病细胞群包括功能不同的细胞亚群，其特征在于不同的耐缺氧性。为了鉴定白血病干细胞（LSC），我们使用了我们开发的培养物再生能力（CRA）测定来定量能够短期重建（STR）的体外干细胞。缺氧强烈抑制MEL细胞群的整体生长，尽管其克隆性，包括具有明显不同的耐缺氧性的祖细胞。这些包括缺氧敏感的集落形成细胞和耐缺氧STR型LSC，能够重新填充CRA测定的二级液体培养物，证实了先前显示的正常造血。STR-型LSC不仅能够在缺氧中存活，而且大多数处于周期中，这与几乎所有缺氧存活的细胞都生长停滞的事实以及我们以前对HSC的发现形成对比。然而，静止LSC也被检测到，能够延迟培养再增殖，具有与STR样LSC相同的效率。事实上，即使是静止的LSC，被认为是维持体内最小的残留疾病，发现在MEL细胞中，表明白血病细胞群的所有主要成分可能存在于克隆细胞系，因此适合于研究个别成分的敏感性治疗。
We showed that resistance to severe hypoxia defines hierarchical levels within normal hematopoietic populations and that hypoxia modulates the balance between generation of progenitors and maintenance of hematopoietic stem cells (HSC) in favor of the latter. This study deals with the effects of hypoxia (0.1% oxygen) in vitro on Friend's murine erythroleukemia (MEL) cells, addressing the question of whether a clonal leukemia cell population comprise functionally different cell subsets characterized by different hypoxia resistance. To identify leukemia stem cells (LSC), we used the Culture Repopulating Ability (CRA) assay we developed to quantify in vitro stem cells capable of short-term reconstitution (STR). Hypoxia strongly inhibited the overall growth of MEL cell population, which, despite its clonality, comprised progenitors characterized by markedly different hypoxia-resistance. These included hypoxia-sensitive colony-forming cells and hypoxia-resistant STR-type LSC, capable of repopulating secondary liquid cultures of CRA assays, confirming what was previously shown for normal hematopoiesis. STR-type LSC were found capable not only of surviving in hypoxia but also of being mostly in cycle, in contrast with the fact that almost all hypoxia-surviving cells were growth-arrested and with what we previously found for HSC. However, quiescent LSC were also detected, capable of delayed culture repopulation with the same efficiency as STR-like LSC. The fact that even quiescent LSC, believed to sustain minimal residual disease in vivo, were found within the MEL cells indicates that all main components of leukemia cell populations may be present within clonal cell lines, which are therefore suitable to study the sensitivity of individual components to treatments.