Metabolic profiling of hypoxic cells revealed a catabolic signature required for cell survival.
Metabolic profiling of hypoxic cells revealed a catabolic signature required for cell survival.
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DOI：
10.1371/journal.pone.0024411
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Gottlieb E
中科院分区：
文献类型：
--
作者：
Frezza C;Zheng L;Tennant DA;Papkovsky DB;Hedley BA;Kalna G;Watson DG;Gottlieb E
低氧是实体瘤血运不良区域的特征之一，但尽管氧分压较低，癌细胞仍能在这些区域存活。对低氧的适应需要生化和遗传反应，最终导致代谢重排，以抵消线粒体呼吸能量供应的减少。对低氧下代谢适应的了解可以揭示新的途径，如果有针对性，这些途径将导致低氧区域的特定死亡。在这项研究中，我们开展了生化和代谢分析，以评估低氧对HCT116癌细胞系细胞代谢的影响。我们在厌氧培养瓶中使用了氧荧光探针来研究低氧条件下的氧耗率，而不需要给细胞重新充氧，并证明了低氧细胞即使在1%的氧气中也可以保持活跃的氧化磷酸化，尽管氧化磷酸化程度降低。线粒体NADH氧化的原位显微镜分析进一步支持了这些结果。然后我们使用代谢组学方法，利用液-质联用(LC-MS)来确定低氧细胞的代谢谱。这一方法揭示了同步和调节的分解代谢作为一种适应生物能量压力的机制的重要性。然后，我们证实了低氧条件下自噬的存在，并证明了抑制这一分解代谢过程显著降低了低氧细胞中的ATP水平，并刺激了低氧诱导的细胞死亡。这些结果表明，在低氧条件下，除了糖酵解外，自噬还需要支持ATP的产生，抑制自噬可能被用于选择性地靶向肿瘤的低氧区域，即实体肿瘤最臭名昭著的耐药区域。
Hypoxia is one of the features of poorly vascularised areas of solid tumours but cancer cells can survive in these areas despite the low oxygen tension. The adaptation to hypoxia requires both biochemical and genetic responses that culminate in a metabolic rearrangement to counter-balance the decrease in energy supply from mitochondrial respiration. The understanding of metabolic adaptations under hypoxia could reveal novel pathways that, if targeted, would lead to specific death of hypoxic regions. In this study, we developed biochemical and metabolomic analyses to assess the effects of hypoxia on cellular metabolism of HCT116 cancer cell line. We utilized an oxygen fluorescent probe in anaerobic cuvettes to study oxygen consumption rates under hypoxic conditions without the need to re-oxygenate the cells and demonstrated that hypoxic cells can maintain active, though diminished, oxidative phosphorylation even at 1% oxygen. These results were further supported by in situ microscopy analysis of mitochondrial NADH oxidation under hypoxia. We then used metabolomic methodologies, utilizing liquid chromatography–mass spectrometry (LC-MS), to determine the metabolic profile of hypoxic cells. This approach revealed the importance of synchronized and regulated catabolism as a mechanism of adaptation to bioenergetic stress. We then confirmed the presence of autophagy under hypoxic conditions and demonstrated that the inhibition of this catabolic process dramatically reduced the ATP levels in hypoxic cells and stimulated hypoxia-induced cell death. These results suggest that under hypoxia, autophagy is required to support ATP production, in addition to glycolysis, and that the inhibition of autophagy might be used to selectively target hypoxic regions of tumours, the most notoriously resistant areas of solid tumours.
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DOI：
10.1016/0005-2736(89)90318-0
发表时间：
1989-04-28
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
WATANABE, H;KOBAYASHI, A;YAMAZAKI, N
通讯作者：
YAMAZAKI, N
影响因子：
10.5
作者：
Wilkinson, Simon;O'Prey, Jim;Ryan, Kevin M.
通讯作者：
Ryan, Kevin M.
影响因子：
9.6
作者：
WILSON, DF;ERECINSKA, M
通讯作者：
ERECINSKA, M
影响因子：
7.7
作者：
Reaves, Marshall Louis;Rabinowitz, Joshua D.
通讯作者：
Rabinowitz, Joshua D.
影响因子：
16
作者：
Kroemer G;Mariño G;Levine B
通讯作者：
Levine B