Targeted killing of a mammalian cell based upon its specialized metabolic state
Targeted killing of a mammalian cell based upon its specialized metabolic state
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DOI：
10.1073/pnas.1111312108
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发表时间：
2011-09-20
影响因子：
11.1
通讯作者：
McKnight, Steven L.
中科院分区：
文献类型：
--
作者：
Alexander, Peter B.;Wang, Jian;McKnight, Steven L.
小鼠胚胎干细胞利用一种线粒体苏氨酸脱氢酶（TDH）将苏氨酸分解代谢为甘氨酸和乙酰辅酶A。对信使核糖核酸（mRNA）丰度的测量表明，胚胎干细胞表达的TDH mRNA水平比所检测的其他七种小鼠组织中的任何一种都高出1000倍以上。当细胞培养基中缺乏苏氨酸时，胚胎干细胞会迅速停止DNA合成，细胞分裂停滞，并最终死亡。这些研究得出结论：小鼠胚胎干细胞处于依赖苏氨酸的代谢状态。基于活性TDH酶对小鼠胚胎干细胞的生长和存活应该是必不可少的这一假设，我们进行了药物筛选，以寻找纯化的TDH酶的特异性抑制剂。这些努力导致发现了一类喹唑啉甲酰胺（Qc）化合物，它们抑制TDH酶将苏氨酸分解代谢为甘氨酸和乙酰辅酶A的能力。给小鼠胚胎干细胞施用TDH的Qc抑制剂会阻碍细胞生长并导致自噬的诱导。相比之下，相同的化学物质在浓度比杀死小鼠胚胎干细胞所需浓度高300倍时，也不会影响海拉细胞的生长。同样观察到，Qc类TDH抑制剂不会影响已知已停止表达TDH的胚胎干细胞衍生的拟胚体细胞的生长或存活。这些研究展示了如何根据一种特定哺乳动物细胞类型的特殊代谢状态来杀死它。
Mouse ES cells use a mitochondrial threonine dehydrogenase (TDH) enzyme to catabolize threonine into glycine and acetylCoA. Measurements of mRNA abundance have given evidence that ES cells express upwards of 1,000-fold higher levels of TDH mRNA than any of seven other mouse tissues tested. When cell culture medium is deprived of threonine, ES cells rapidly discontinue DNA synthesis, arrest cell division, and eventually die. Such studies led to the conclusion that mouse ES cells exist in a threonine-dependent metabolic state. Proceeding with the assumption that the active TDH enzyme should be essential for the growth and viability of mouse ES cells, we performed a drug screen in search of specific inhibitors of the purified TDH enzyme. Such efforts led to the discovery of a class of quinazolinecarboxamide (Qc) compounds that inhibit the ability of the TDH enzyme to catabolize threonine into glycine and acetyl-CoA. Administration of Qc inhibitors of TDH to mouse ES cells impeded cell growth and resulted in the induction of autophagy. By contrast, the same chemicals failed to affect the growth of HeLa cells at concentrations 300-fold higher than that required to kill mouse ES cells. It was likewise observed that the Qc class of TDH inhibitors failed to affect the growth or viability of ES cell-derived embryoid body cells known to have extinguished TDH expression. These studies demonstrate how it is possible to kill a specific mammalian cell type on the basis of its specialized metabolic state.