Physiologic oxygen concentration enhances the stem-like properties of CD133+ human glioblastoma cells in vitro.
Physiologic oxygen concentration enhances the stem-like properties of CD133+ human glioblastoma cells in vitro.
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DOI：
10.1158/1541-7786.mcr-08-0360
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发表时间：
2009-04
期刊：
影响因子：
--
通讯作者：
Tofilon PJ
中科院分区：
文献类型：
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作者：
McCord AM;Jamal M;Shankavaram UT;Lang FF;Camphausen K;Tofilon PJ
从人胶质母细胞瘤（GB）手术标本中分离的肿瘤干细胞（TSC）的体外研究主要在20%的大气氧气水平下进行。为了确定与原位条件更一致的氧气水平是否会影响其干细胞样特性，我们比较了在20%和7%氧气条件下生长的GB TSCs。从三个GB神经球培养物中分选的CD133+细胞在7% O2下生长，可以减少其倍增时间，并通过克隆原性提高自我更新潜力。此外，在7%的氧气下，培养物表现出沿胶质和神经元途径分化的增强能力。与20%氧气相比，7%氧气下的生长导致神经干细胞标记物CD133和巢蛋白以及干细胞标记物Oct4和Sox2的表达水平增加。此外，虽然缺氧诱导因子1α在7%氧条件下生长的CD133+ TSCs中不受影响，但与20%氧条件下相比，缺氧诱导因子2α的表达水平更高。通过微阵列分析生成的基因表达谱显示，将氧水平降低至7%会导致大量基因的上调和下调，在三种CD133+培养物中，共有140多种基因受到影响。此外，在7%氧条件下上调的基因本体类别包括与干细胞或GB TSCs相关的基因。因此，这些数据表明，7%的生理相关氧水平下的生长增强了CD133+ GB细胞的干细胞样表型。
In vitro investigations of tumor stem-like cells (TSC) isolated from human glioblastoma (GB) surgical specimens have been done primarily at an atmospheric oxygen level of 20%. To determine whether an oxygen level more consistent with in situ conditions affects their stem cell–like characteristics, we compared GB TSCs grown under conditions of 20% and 7% oxygen. Growing CD133+ cells sorted from three GB neurosphere cultures at 7% O2 reduced their doubling time and increased the self-renewal potential as reflected by clonogenicity. Furthermore, at 7% oxygen, the cultures exhibited an enhanced capacity to differentiate along both the glial and neuronal pathways. As compared with 20%, growth at 7% oxygen resulted in an increase in the expression levels of the neural stem cell markers CD133 and nestin as well as the stem cell markers Oct4 and Sox2. In addition, whereas hypoxia inducible factor 1α was not affected in CD133+ TSCs grown at 7% O2, hypoxia-inducible factor 2α was expressed at higher levels as compared with 20% oxygen. Gene expression profiles generated by microarray analysis revealed that reducing oxygen level to 7% resulted in the up-regulation and down-regulation of a significant number of genes, with more than 140 being commonly affected among the three CD133+ cultures. Furthermore, Gene Ontology categories up-regulated at 7% oxygen included those associated with stem cells or GB TSCs. Thus, the data presented indicate that growth at the more physiologically relevant oxygen level of 7% enhances the stem cell–like phenotype of CD133+ GB cells.