Understanding metabolic pathways that support redox homeostasis in cancer

了解支持癌症氧化还原稳态的代谢途径

• 批准号: 9257990
• 负责人: Alexander Muir
• 金额: $ 5.67万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9257990
• 关键词: Adenocarcinoma Cell; Amino Acids; Anabolism; Biochemical Pathway; Biomass; CRISPR screen; CRISPR/Cas technology; Cell Line; Cell Proliferation; Cells; Citrates; Complex; Electron Transport; Environment; Enzymes; Equilibrium; Fatty Acids; Fatty acid glycerol esters; Gene Targeting; Glutamine; Growth; Guide RNA; Homeostasis; Human; Hypoxia; Impairment; In Vitro; Knowledge; Lead; Malignant Neoplasms; Mass Fragmentography; Mediating; Metabolic; Metabolic Pathway; Metabolism; Mutation; NADH; Natural regeneration; Neoplasms in Vascular Tissue; Non-Essential Amino Acid; Nucleotides; Nutrient; Oxidants; Oxidation-Reduction; Oxygen; Pancreas; Pancreatic Ductal Adenocarcinoma; Pathway interactions; Production; Proliferating; Proline; Reaction; Role; Testing; Therapeutic; Work; base; cancer cell; fatty acid biosynthesis; fatty acid metabolism; genome editing; impaired capacity; in vivo; insight; lipid biosynthesis; lipid metabolism; metabolic phenotype; overexpression; pancreatic cancer cells; pancreatic neoplasm; prevent; stable isotope; tumor; tumor growth; tumor metabolism

Project Summary/Abstract Pancreatic ductal adenocarcinoma (PDAC) cancer cells proliferate within particularly fibrotic and poorly vascularized tumors. Although PDAC cells exist within a tumor environment with limited nutrients and oxygen, these cells nevertheless aggressively proliferate and grow. Limited electron transport chain (ETC) activity caused by oxygen limitation in this environment creates a redox balance problem such that NADH cannot be recycled by the ETC to NAD+. Under these conditions, NAD+ can become limiting for growth, a condition we term electron acceptor insufficiency. Cells proliferating under hypoxic conditions must overcome this electron acceptor insufficiency in order to proliferate. We hypothesize that oxygen limitation leads to reliance on alternative metabolic pathways to maintain redox balance, biomass synthesis and proliferation. While many studies have focused on aberrant PDAC metabolism triggered by genetic alterations common to this malignancy, there is little understanding of the environment- dependent alterations in tumor cell metabolism that are required for PDAC proliferation in harsh oxygen and nutrient limiting conditions. The proposed work will identify the metabolic requirements of PDAC cells brought on by hypoxia. First I will test whether otherwise unexplained PDAC metabolic phenotypes might drive reactions that allow these cells to proliferate in limited oxygen. Specifically, I will test the hypotheses that proline and fatty acid metabolism allow hypoxic PDAC cells to overcome electron acceptor insufficiency and are functionally important for hypoxic PDAC proliferation. Lastly, I will perform a metabolic gene targeted CRISPR/Cas9 screen, to identify the set of metabolic enzymes that are required for PDAC redox homeostasis and proliferation under environmental hypoxia. The results of these studies will be the first to identify metabolic pathways that PDAC cells require for redox balance under hypoxia. This will provide a metabolic basis for understanding how PDAC cells continue to proliferate under conditions that otherwise severely limit perturb cellular redox balance and synthesis of metabolites required for growth. This is important as targeted inhibition of the set of reactions that PDAC cells use to maintain redox balance and prevent electron acceptor insufficiency may selectively prevent PDAC cell proliferation and have therapeutic value. Thus, this work may reveal ways to target PDAC based on the environmental context of these cancers.

项目摘要/摘要 胰腺导管腺癌(PDAC)癌细胞增殖，尤其是纤维性和 血运不良的肿瘤。尽管PDAC细胞存在于肿瘤环境中， 在营养和氧气的作用下，这些细胞仍然会积极地增殖和生长。有限 在这种环境中，氧限制引起的电子传输链(ETC)活性产生了 氧化还原平衡问题，使得NADH不能被ETC回收到NAD+。在这些下面 在某些条件下，NAD+会限制生长，我们称之为电子受体 不够用。在低氧条件下增殖的细胞必须克服这种电子受体 为了扩散而不足的。我们假设氧气限制会导致对 维持氧化还原平衡、生物量合成和增殖的替代代谢途径。 虽然许多研究都集中在基因引发的PDAC代谢异常上 这种恶性肿瘤的常见变化，人们对环境的了解很少- HASH中PDAC增殖所需的肿瘤细胞代谢的依赖性改变 氧气和营养限制条件。拟议的工作将确定新陈代谢 缺氧对PDAC细胞的要求。首先，我要测试一下是否有其他情况 不明原因的PDAC代谢表型可能会驱动反应，使这些细胞 在有限的氧气中繁殖。具体地说，我将测试以下假设：Pro和脂肪酸 新陈代谢使缺氧的PDAC细胞克服电子受体不足，并 对缺氧性PDAC的增殖具有重要作用。最后，我将执行一个新陈代谢基因 靶向CRISPR/Cas9筛选，以确定所需的一组代谢酶 环境低氧条件下PDAC氧化还原动态平衡和增殖。这些研究的结果 研究将首次确定PDAC细胞氧化还原平衡所需的代谢途径 在低氧条件下。这将为理解PDAC细胞如何继续生存提供代谢基础 在严重限制细胞氧化还原平衡的条件下增殖 生长所需的代谢物的合成。这一点很重要，因为有针对性地抑制一组 PDAC细胞用来维持氧化还原平衡和防止电子受体的反应 功能不全可能选择性地阻止PDAC细胞的增殖，具有治疗价值。因此， 这项工作可能会揭示基于这些环境背景的PDAC目标的方法 癌症。