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.

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 （氧化磷）。由于观察到，针对癌症代谢的努力主要集中在糖酵解上 癌细胞优先利用这种模式，称为瓦尔堡效应。然而，人们重新燃起兴趣 通过其效应器电子传递链 (ETC) 靶向 OXPHOS，主要是因为这一发现 广泛使用的抗糖尿病药物二甲双胍可降低糖尿病患者患癌症的风险并导致死亡 通过抑制 ETC 复合物 I 在体外和体内抑制癌细胞。 ETC 由五个复合物组成，这些复合物的作用是在一系列氧化还原反应中顺序转移电子。 导致 ATP 生成的反应。由于针对癌症的 ETC 的研究相对较新， 基础知识，例如对 ETC 的依赖情况，更具体地说，特定的 ETC 跨癌症的复合物仍然未知。为了研究这些问题，我们的实验室定义了 依赖于对一大组不同癌细胞系中每个 ETC 复合物的抑制。有趣的是，细胞 各系对各个 ETC 复合物的抑制反应各异，复合物 I 抑制产生均质 细胞死亡和复合物 II-V 抑制导致异质细胞死亡。我们天真地期望 ETC 复合体 由于 ETC 的线性关系，依赖性将相互关联；额外的初步数据显示 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，独立于其在细胞中的典型作用 氧化磷。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 复杂依赖性的典型代谢机制。我们发现了多种生物合成 调节单个 ETC 复合物抑制并受其调节的代谢途径。 特别有趣的是，我们发现了复合物 III 抑制之间的新型合成致死组合 以及具有良好转化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，例如胆固醇和泛醌，并与肿瘤发生有关 和进展；此外，该途径受到他汀类药物的抑制，他汀类药物在临床上常用来降低 胆固醇水平。由于描述甲羟戊酸途径调节复合物 III 的机制尚未 尽管尚未得到阐明，但出于基本和翻译原因，这是一种值得研究的有趣关系。 在本提案中，我们将研究泛醌合成调节关系的假设 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 在免疫功能正常和免疫缺陷的小鼠癌症模型中使用他汀类药物可以增强这种作用。