Cell Metabolism & Myc induced growth death, & neoplasia

描述(申请人提供)：已知癌基因c-Myc与许多人类癌症的发生有关。基因组学和蛋白质组学已经确定了许多与细胞代谢有关的潜在c-Myc靶点。功能研究表明，参与葡萄糖代谢的基因受c-Myc的调控，我们最近的工作为Myc参与氧化磷酸化(OXPHOS)提供了证据。然而，Myc对代谢基因的调控对功能的影响还没有得到彻底的研究。目前，Myc诱导的癌症所必需的代谢途径尚不清楚，也不能作为药物干预的靶点。这项提议的第一个目标是在体内和体外Myc诱导生长、死亡或肿瘤的条件下，为Myc表达细胞产生代谢谱。这些研究的结果将有助于确定与Myc诱导的肿瘤相关的代谢途径的关键干预点。第二个目标是确定Myc诱导的与细胞凋亡和转化相关的基因。了解这些基因的特性将使未来的研究能够开发出诱导Myc表达癌细胞凋亡或使其无法转化的方法。这一建议的具体目的包括：1)确定Myc控制葡萄糖代谢和OXPHOS的能力如何在有利于生长、死亡或肿瘤的条件下通过糖酵解和TCA循环影响碳代谢产物的流动；2)识别和表征参与Myc诱导的细胞凋亡和转化的基因。这项建议中的研究利用组织特异性、可诱导的转基因小鼠和细胞模型来了解c-Myc上调时能量代谢的变化。这些研究将包括使用13C核磁共振和同位素分析来分析碳流和代谢通量。线粒体代谢将通过耗氧量、OXPHOS酶分析、膜电位和活性氧产生来评估。碳代谢对细胞的生存和增殖至关重要，我们希望我们的代谢方法能够更好地理解c-Myc诱导的肿瘤转化背后的代谢事件，从而为癌症治疗提供新的靶点。

DESCRIPTION (provided by applicant): The oncogene c-Myc is known to be involved in the development of many human cancers. Genomics and proteomics have identified many potential c-Myc targets involved in cell metabolism. Functional studies have shown that genes involved in glucose metabolism are regulated by c-Myc and our recent work provides evidence for Myc's involvement in oxidative phosphorylation (OXPHOS). However, the functional impact of Myc's regulation of metabolic genes has not been thoroughly investigated. Currently, the metabolic pathways essential for Myc-induced cancers are unknown and cannot be targeted for drug intervention. The first goal of this proposal is to generate metabolic profiles for Myc expressing cells under conditions where Myc induces growth, death or neoplasia in vivo and in vitro. The result generated from these studies will facilitate the identification of key points of intervention in metabolic pathways linked to Myc-induced neoplasia. A second goal is to identify Myc-induced genes involved in apoptosis and transformation. Knowing the identity of these genes will enable future studies to develop methods that induce apoptosis or disable transformation in Myc expressing cancer cells. The specific aims of this proposal include: 1) to determine how Myc's ability to control glucose metabolism and OXPHOS influences the flow of carbon metabolites through glycolysis and the TCA cycle under conditions that are conducive to growth, death or neoplasia and 2) to identify and characterize genes that are involved in Myc-induced apoptosis and transformation. The studies in this proposal utilize tissue specific, inducible transgenic mouse and cell models to understand the changes in energy metabolism that occur on up-regulation of c-Myc. These studies will involve an analysis of carbon flow and metabolic flux using 13C NMR and isotopomer analysis. Mitochondrial metabolism will be evaluated by oxygen consumption, OXPHOS enzyme assays, membrane potential and reactive oxygen species generation. Carbon metabolism is essential to cell survival and proliferation and we would expect that our metabolic approach would provide a greater understanding of the metabolic events underlying c-Myc induced neoplastic transformation and thereby provide novel target for cancer therapeutics.