Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Mathematical Modeling of Cellular Processes, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
Sci Rep. 2020 Apr 28;10(1):7157. doi: 10.1038/s41598-020-64040-1.
N-Myc is a transcription factor that is aberrantly expressed in many tumor types and is often correlated with poor patient prognosis. Recently, several lines of evidence pointed to the fact that oncogenic activation of Myc family proteins is concomitant with reprogramming of tumor cells to cope with an enhanced need for metabolites during cell growth. These adaptions are driven by the ability of Myc proteins to act as transcriptional amplifiers in a tissue-of-origin specific manner. Here, we describe the effects of N-Myc overexpression on metabolic reprogramming in neuroblastoma cells. Ectopic expression of N-Myc induced a glycolytic switch that was concomitant with enhanced sensitivity towards 2-deoxyglucose, an inhibitor of glycolysis. Moreover, global metabolic profiling revealed extensive alterations in the cellular metabolome resulting from overexpression of N-Myc. Limited supply with either of the two main carbon sources, glucose or glutamine, resulted in distinct shifts in steady-state metabolite levels and significant changes in glutathione metabolism. Interestingly, interference with glutamine-glutamate conversion preferentially blocked proliferation of N-Myc overexpressing cells, when glutamine levels were reduced. Thus, our study uncovered N-Myc induction and nutrient levels as important metabolic master switches in neuroblastoma cells and identified critical nodes that restrict tumor cell proliferation.
N-Myc 是一种转录因子,在许多肿瘤类型中异常表达,通常与患者预后不良相关。最近,有几条证据表明,Myc 家族蛋白的致癌激活伴随着肿瘤细胞的重编程,以应对细胞生长过程中对代谢物的增强需求。这些适应是由 Myc 蛋白在组织特异性的方式作为转录放大器的能力驱动的。在这里,我们描述了 N-Myc 过表达对神经母细胞瘤细胞代谢重编程的影响。N-Myc 的异位表达诱导了糖酵解开关,同时增强了对 2-脱氧葡萄糖的敏感性,2-脱氧葡萄糖是一种糖酵解抑制剂。此外,全局代谢谱分析显示,由于 N-Myc 的过表达,细胞代谢组发生了广泛的改变。两种主要碳源(葡萄糖或谷氨酰胺)的供应有限,导致稳态代谢物水平的明显变化和谷胱甘肽代谢的显著变化。有趣的是,当谷氨酰胺水平降低时,干扰谷氨酰胺-谷氨酸转化优先阻断 N-Myc 过表达细胞的增殖。因此,我们的研究揭示了 N-Myc 的诱导和营养水平是神经母细胞瘤细胞中重要的代谢主开关,并确定了限制肿瘤细胞增殖的关键节点。