Lee Derek C, Ta Linh, Mukherjee Purna, Duraj Tomas, Domin Marek, Greenwood Bennett, Karmacharya Srada, Narain Niven R, Kiebish Michael, Chinopoulos Christos, Seyfried Thomas N
Department of Biology, Boston College, Massachusetts, USA.
Mass Spectrometry Center, Chemistry Department, Boston College, Massachusetts, USA.
ASN Neuro. 2024;16(1):2422268. doi: 10.1080/17590914.2024.2422268. Epub 2024 Dec 2.
Energy is necessary for tumor cell viability and growth. Aerobic glucose-driven lactic acid fermentation is a common metabolic phenotype seen in most cancers including malignant gliomas. This metabolic phenotype is linked to abnormalities in mitochondrial structure and function. A luciferin-luciferase bioluminescence ATP assay was used to measure the influence of amino acids, glucose, and oxygen on ATP content and viability in mouse (VM-M3 and CT-2A) and human (U-87MG) glioma cells that differed in cell biology, genetic background, and species origin. Oxygen consumption was measured using the Resipher system. Extracellular lactate and succinate were measured as end products of the glycolysis and glutaminolysis pathways, respectively. The results showed that: (1) glutamine was a source of ATP content irrespective of oxygen. No other amino acid could replace glutamine in sustaining ATP content and viability; (2) ATP content persisted in the absence of glucose and under hypoxia, ruling out substantial contribution through either glycolysis or oxidative phosphorylation (OxPhos) under these conditions; (3) Mitochondrial complex IV inhibition showed that oxygen consumption was not an accurate measure for ATP production through OxPhos. The glutaminase inhibitor, 6-diazo-5-oxo-L-norleucine (DON), reduced ATP content and succinate export in cells grown in glutamine. The data suggests that mitochondrial substrate level phosphorylation in the glutamine-driven glutaminolysis pathway contributes to ATP content in these glioma cells. A new model is presented highlighting the synergistic interaction between the high-throughput glycolysis and glutaminolysis pathways that drive malignant glioma growth and maintain ATP content through the aerobic fermentation of both glucose and glutamine.
能量对于肿瘤细胞的生存和生长至关重要。有氧葡萄糖驱动的乳酸发酵是包括恶性神经胶质瘤在内的大多数癌症中常见的代谢表型。这种代谢表型与线粒体结构和功能异常有关。使用荧光素-荧光素酶生物发光ATP测定法来测量氨基酸、葡萄糖和氧气对小鼠（VM-M3和CT-2A）及人（U-87MG）神经胶质瘤细胞中ATP含量和活力的影响，这些细胞在细胞生物学、遗传背景和物种来源方面存在差异。使用Resipher系统测量氧气消耗。分别测量细胞外乳酸和琥珀酸作为糖酵解和谷氨酰胺分解途径的终产物。结果表明：（1）无论有无氧气，谷氨酰胺都是ATP含量的来源。没有其他氨基酸能够替代谷氨酰胺来维持ATP含量和活力；（2）在没有葡萄糖和缺氧的情况下，ATP含量仍然存在，排除了在这些条件下通过糖酵解或氧化磷酸化（OxPhos）产生大量ATP的可能性；（3）线粒体复合物IV抑制表明，氧气消耗并非通过OxPhos产生ATP的准确衡量指标。谷氨酰胺酶抑制剂6-重氮-5-氧代-L-正亮氨酸（DON）降低了在谷氨酰胺中生长的细胞中的ATP含量和琥珀酸输出。数据表明，谷氨酰胺驱动的谷氨酰胺分解途径中的线粒体底物水平磷酸化有助于这些神经胶质瘤细胞中的ATP含量。提出了一个新模型，突出了高通量糖酵解和谷氨酰胺分解途径之间的协同相互作用，这两条途径驱动恶性神经胶质瘤生长并通过葡萄糖和谷氨酰胺的有氧发酵维持ATP含量。
