Quantitative analysis of acetyl-CoA production in hypoxic cancer cells reveals substantial contribution from acetate.
Quantitative analysis of acetyl-CoA production in hypoxic cancer cells reveals substantial contribution from acetate.
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DOI：
10.1186/2049-3002-2-23
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发表时间：
2014
影响因子：
5.9
通讯作者：
Rabinowitz JD
中科院分区：
文献类型：
--
作者：
Kamphorst JJ;Chung MK;Fan J;Rabinowitz JD
细胞生长需要脂肪酸来合成膜。脂肪酸由乙酰辅酶A (AcCoA) 形式的 2 个碳单元组装而成。在营养和氧气充足的条件下，乙酰辅酶A主要来源于葡萄糖。然而，在缺氧情况下，从葡萄糖到乙酰辅酶A的通量减少，而谷氨酰胺对乙酰辅酶A的贡献分数增加。然而，其他乙酰辅酶A来源的重要性尚未经过严格评估。在这里，我们使用 13C 示踪剂和质谱法定量研究缺氧时乙酰辅酶 A 的来源。在含氧量正常的条件下，培养细胞90%以上的乙酰辅酶A是由葡萄糖和谷氨酰胺衍生的碳产生的。在缺氧细胞中，这种贡献下降，跨细胞系从 50% 到 80% 不等。因此，在缺氧条件下，一种或多种额外的底物显着促进乙酰辅酶A的产生。 13C-示踪剂实验表明，氨基酸和脂肪酸都不是这种乙酰辅酶A的主要来源。相反，主要的附加来源是醋酸盐。尽管乙酸盐以低浓度（50–500 μM）存在于培养基中，但它的贡献很大。乙酸是缺氧时乙酰辅酶A的重要来源。抑制乙酸盐代谢可能会损害肿瘤生长。本文的在线版本 (doi:10.1186/2049-3002-2-23) 包含补充材料，可供授权用户使用。
Cell growth requires fatty acids for membrane synthesis. Fatty acids are assembled from 2-carbon units in the form of acetyl-CoA (AcCoA). In nutrient and oxygen replete conditions, acetyl-CoA is predominantly derived from glucose. In hypoxia, however, flux from glucose to acetyl-CoA decreases, and the fractional contribution of glutamine to acetyl-CoA increases. The significance of other acetyl-CoA sources, however, has not been rigorously evaluated. Here we investigate quantitatively, using 13C-tracers and mass spectrometry, the sources of acetyl-CoA in hypoxia. In normoxic conditions, cultured cells produced more than 90% of acetyl-CoA from glucose and glutamine-derived carbon. In hypoxic cells, this contribution dropped, ranging across cell lines from 50% to 80%. Thus, under hypoxia, one or more additional substrates significantly contribute to acetyl-CoA production. 13C-tracer experiments revealed that neither amino acids nor fatty acids are the primary source of this acetyl-CoA. Instead, the main additional source is acetate. A large contribution from acetate occurs despite it being present in the medium at a low concentration (50–500 μM). Acetate is an important source of acetyl-CoA in hypoxia. Inhibition of acetate metabolism may impair tumor growth. The online version of this article (doi:10.1186/2049-3002-2-23) contains supplementary material, which is available to authorized users.