Brief Reports: Controlling the Survival of Human Pluripotent Stem Cells by Small Molecule-Based Targeting of Topoisomerase II Alpha
Brief Reports: Controlling the Survival of Human Pluripotent Stem Cells by Small Molecule-Based Targeting of Topoisomerase II Alpha
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DOI：
10.1002/stem.1888
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发表时间：
2015-03-01
期刊：
影响因子：
5.2
通讯作者：
Benvenisty, Nissim
中科院分区：
文献类型：
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作者：
Ben-David, Uri;Cowell, Ian G.;Benvenisty, Nissim
多能特异性抑制剂（Pluripotent-specific inhibitors，PluriSIns）是研究人多能干细胞（human pluripotent stem cells，hPSC）存活机制的有力工具。在这里，我们描述了PluriSIn#2的作用机制，PluriSIn#2是一种选择性消除未分化的hPSC的化合物，同时保留了衍生自它们的各种其他细胞类型。毒理基因组学分析预测该化合物是拓扑异构酶抑制剂。基因表达分析显示，人类拓扑异构酶之一拓扑异构酶II α（TOP 2A）在hPSC中独特表达：TOP 2A在未分化细胞中高度表达，在其分化期间下调，并且其表达取决于核心多能性转录因子的表达。此外，在未分化的hPSC中基于siRNA的TOP 2A敲低导致其细胞死亡，揭示了TOP 2A表达是这些细胞存活所必需的。我们发现PluriSIn#2不直接抑制TOP 2A酶活性，而是选择性抑制其转录，从而显著降低TOP 2A蛋白水平。由于未分化的hPSC需要TOP 2A活性才能存活，因此PluriSIn#2对TOP 2A的抑制导致其细胞死亡。因此，可以利用TOP 2A依赖性从培养物中选择性消除致瘤性hPSC。
Pluripotent-specific inhibitors (PluriSIns) make a powerful tool to study the mechanisms controlling the survival of human pluripotent stem cells (hPSCs). Here, we characterize the mechanism of action of PluriSIn#2, a compound that selectively eliminates undifferentiated hPSCs, while sparing various other cell types derived from them. Toxicogenomic analysis predicts this compound to be a topoisomerase inhibitor. Gene expression analyses reveal that one of the human topoisomerase enzymes, topoisomerase II alpha (TOP2A), is uniquely expressed in hPSCs: TOP2A is highly expressed in undifferentiated cells, is downregulated during their differentiation, and its expression depends on the expression of core pluripotency transcription factors. Furthermore, siRNA-based knockdown of TOP2A in undifferentiated hPSCs results in their cell death, revealing that TOP2A expression is required for the survival of these cells. We find that PluriSIn#2 does not directly inhibit TOP2A enzymatic activity, but rather selectively represses its transcription, thereby significantly reducing TOP2A protein levels. As undifferentiated hPSCs require TOP2A activity for their survival, TOP2A inhibition by PluriSIn#2 thus causes their cell death. Therefore, TOP2A dependency can be harnessed for the selective elimination of tumorigenic hPSCs from culture.