Defining the Mechanistic Determinants of Response to Selective Electron Transport Chain Inhibition in Cancer

定义癌症选择性电子传递链抑制反应的机制决定因素

• 批准号: 10154758
• 负责人: Amy Elizabeth Stewart
• 金额: $ 3.8万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10154758
• 关键词: Address; Antidiabetic Drugs; Antimycin A; Biological; CRISPR screen; Cancer Model; Cancer cell line; Cell Culture Techniques; Cell Death; Cell Line; Cell Survival; Cell physiology; Cells; Cholesterol; Clinic; Clinical; Clinical Trials; Clustered Regularly Interspaced Short Palindromic Repeats; Combined Modality Therapy; Complex; Culture Media; DHODH gene; Data; Dependence; Diabetes Mellitus; Dose; Drug Targeting; Electron Transport; Electron Transport Complex III; Energy Metabolism; Enzymes; Exhibits; Generations; Genes; Glycolysis; Heterogeneity; Immune; Immunocompetent; In Vitro; Incidence; Individual; Knock-out; Knowledge; Link; Malignant Neoplasms; Measures; Metabolic; Metabolic Pathway; Metabolism; Metformin; NADH dehydrogenase (ubiquinone); Oxidation-Reduction; Oxidative Phosphorylation; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Production; Pyrimidine; Reaction; Regulation; Role; Series; Testing; Therapeutic; Therapeutic Effect; Treatment Efficacy; Ubiquinone; Warburg Effect; Work; base; cancer cell; cancer risk; cancer therapy; diabetic patient; expectation; experimental study; in vivo; inhibitor/antagonist; interest; isoprenoid; melanoma; metabolomics; mevalonate; mouse model; neoplastic cell; novel; response; treatment response; tumor initiation; tumor progression

Abstract: Cells utilize two major modes of energy metabolism: glycolysis and oxidative phosphorylation (OXPHOS). Efforts to target metabolism in cancer have mainly focused on glycolysis due to the observation that cancer cells preferentially utilize this mode, termed the Warburg effect. However, there is renewed interest in targeting OXPHOS through its effector, the electron transport chain (ETC), primarily because of the discovery that the widely used anti-diabetic drug, metformin, lowers risk of cancer incidence in diabetes patients and kills cancer cells in vitro and in vivo through inhibiting complex I of the ETC. The ETC is composed of five complexes that work to sequentially transfer electrons in a series of redox reactions that result in the generation of ATP. As the efforts to target the ETC in cancer are relatively recent, fundamental knowledge such as the landscape of dependence on the ETC and more specifically, particular ETC complexes, across cancers remains unknown. To investigate these questions, our lab has defined the dependence on inhibition of each ETC complex across a large panel of diverse cancer cell lines. Intriguingly, cell lines respond variably to inhibition of individual ETC complexes, with complex I inhibition yielding homogeneous cell death and complex II-V inhibition causing heterogeneous cell death. We naively expected that ETC complex dependencies would correlate with each other due to the linearity of the ETC; additional preliminary data show that ATP levels remain unchanged with ETC inhibition. Taken together, these results suggest that ETC complexes may play important roles in maintaining cell viability independently of their canonical roles in OXPHOS. To that end, we performed CRISPR/Cas9 screens and metabolomics analyses to determine the non- canonical metabolic mechanisms modulating ETC complex dependences. We identified various biosynthetic metabolic pathways that modulate, and are modulated by, individual ETC complex inhibition. Of particular interest, we identified a novel synthetic lethal combination between complex III inhibition and loss of the mevalonate pathway that has promising translational potential. The mevalonate pathway synthesizes various isoprenoids, such as cholesterol and ubiquinone, and has been implicated in tumor initiation and progression; additionally, this pathway is inhibited by statin drugs, commonly used in the clinic to lower cholesterol levels. As mechanisms describing the regulation of complex III by the mevalonate pathway have not yet been elucidated, this is an interesting relationship to investigate for both basic and translational reasons. In this proposal, we will investigate the hypothesis that ubiquinone synthesis regulates the relationship between the mevalonate pathway and complex III. We will also determine if the efficacy of complex III inhibition can be enhanced by using statins in both immune-competent and immune-deficient mouse models of cancer.

翻译后摘要：细胞利用两种主要的能量代谢模式：糖酵解和氧化磷酸化 （OXPHOS）。靶向癌症代谢的努力主要集中在糖酵解，因为观察到， 癌细胞优先利用这种称为瓦尔堡效应的模式。然而，人们对以下方面重新产生了兴趣： 通过其效应器，电子传递链（ETC）靶向OXPHOS，主要是因为发现 广泛使用的抗糖尿病药物二甲双胍可以降低糖尿病患者的癌症发病率， 通过抑制ETC的复合物I，在体内外抑制癌细胞。 ETC由五种复合物组成，它们在一系列氧化还原反应中顺序转移电子。 这些反应导致ATP的产生。由于靶向癌症ETC的努力相对较新， 基础知识，如对ETC的依赖情况，更具体地说，特别是ETC 在癌症中的作用仍然未知。为了研究这些问题，我们的实验室定义了 在一个大的小组的不同的癌细胞系的每个ETC复合物的抑制的依赖性。有趣的是，细胞 线响应于单个ETC复合物的抑制，复合物I抑制产生均匀的 细胞死亡和复合物II-V抑制引起异质性细胞死亡。我们天真地以为ETC复合体 由于ETC的线性，相关性将相互关联;其他初步数据显示 ATP水平在ETC抑制下保持不变。综上所述，这些结果表明，ETC 复合物可能在维持细胞活力方面发挥重要作用，而不依赖于它们在细胞增殖中的典型作用。 OXPHOS。为此，我们进行了CRISPR/Cas9筛选和代谢组学分析，以确定非- 调节ETC复合物依赖性的典型代谢机制。我们发现了各种生物合成的 调节个体ETC复合物抑制和被个体ETC复合物抑制调节的代谢途径。 特别令人感兴趣的是，我们确定了一种新的合成致死组合之间的复合物III抑制 以及具有有希望的翻译潜力的甲羟戊酸途径的丧失。甲羟戊酸途径 合成各种类异戊二烯，如胆固醇和泛醌，并与肿瘤的发生有关 此外，该途径被他汀类药物抑制，通常用于临床以降低 胆固醇水平。由于描述通过甲羟戊酸途径调节复合物III的机制还没有 尽管这一关系尚未得到阐明，但无论是从基本原因还是从翻译原因来看，这都是一个值得研究的有趣关系。 在这个建议中，我们将调查的假设，泛醌合成调节的关系， 在甲羟戊酸途径和复合物III之间。我们还将确定复合物III抑制的功效是否 可以通过在免疫活性和免疫缺陷小鼠癌症模型中使用他汀类药物来增强。