The Role of Mortalin in Thyroid Cancer

Mortalin 在甲状腺癌中的作用

• 批准号: 10583210
• 负责人: Jong-In Park
• 金额: $ 43.63万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-10 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10583210
• 关键词: ATP Citrate (pro-S)-Lyase; Acetyl Coenzyme A; Address; Bioenergetics; Biology; Cell Death Induction; Cell Line; Cell Proliferation; Cell Survival; Cessation of life; Characteristics; Citrates; Citric Acid Cycle; Collaborations; Common Neoplasm; DNA; Data; Data Set; Development; ERR1 protein; Enzymes; GRP75; Genetic Transcription; Genus Hippocampus; Glucose; Glycolysis; Glycolysis Inhibition; Goals; Heat-Shock Proteins 70; In Vitro; Isotopes; Maintenance; Malignant Neoplasms; Malignant neoplasm of thyroid; Mediating; Metabolic; Metabolic stress; Metabolism; Mitochondria; Molecular; Molecular Chaperones; NCOR1 gene; Oncogene Activation; Oncogenes; Oncogenic; Orphan; Oxidative Stress; Patients; Process; Production; Proliferating; Pyruvate; Pyruvate Kinase; Reactive Oxygen Species; Regulation; Research; Risk; Role; Signal Transduction; Stress; Testing; The Cancer Genome Atlas; Therapeutic; Translating; Tumor Cell Line; Tumor Subtype; Up-Regulation; Warburg Effect; cancer subtypes; cell transformation; clinical efficacy; efficacy evaluation; in vivo; inhibitor; knock-down; metabolome; mortalin; neoplastic cell; novel strategies; overexpression; patient derived xenograft model; promoter; stress tolerance; synergism; therapeutic target; thyroid neoplasm; transcription factor; transcriptome sequencing; tumor; tumor metabolism

The goal of this project is to elucidate the mechanism by which mortalin is upregulated in thyroid cancer, determine the role of mortalin for tumor cell metabolism, and evaluate the potential of the metabolic processes that mortalin regulates as a therapeutic target. Metabolic reprogramming in the processes of energy and building block production is critical for tumor development and maintenance, but is associated with the risk of a lethal metabolic stress. It is therefore conceivable that malignant tumor cells might have successfully developed a protective mechanism in this context. If identified, such a mechanism may be targeted to unleash a death signal in tumor cells. We previously demonstrated that depletion of mortalin (GRP75/HSPA9), a molecular chaperone in the HSP70 family, causes lethal bioenergetic and oxidative stress in tumor cells, proposing that mortalin upregulation is a mechanism to protect tumor cells from a metabolic stress. Current understanding of the role of mortalin and its regulation is very limited in thyroid cancer, which is a metabolically active tumor. Our analysis of the TCGA RNAseq dataset revealed that a thyroid cancer-specific correlation exists between mortalin and ESRRA, an orphan transcription factor that regulates metabolic reprogramming. In our preliminary study, ESRRA depletion downregulated mortalin expression and induced cell death in different thyroid tumor cell lines, while this lethality was substantially abrogated by mortalin overexpression. These data led us to hypothesize that ESRRA is a tumor type- specific transcription factor that mediates mortalin overexpression in thyroid cancer and that mortalin is necessary for ESRRA to regulate thyroid tumor cell metabolism. Our metabolome analysis suggests that mortalin knockdown markedly depletes acetyl-CoA and its precursors in the context of the reductive TCA cycle, while increasing lactate and glucose. Moreover, depletion of ATP-citrate lyase (ACL), the enzyme that synthesizes cytosolic acetyl-CoA from citrate produced through the reductive TCA cycle, induced similar lethal effects as mortalin depletion whereas overexpression of pyruvate kinase M2 (PKM2), the enzyme that produces pyruvate to often facilitate the Warburg effect, conferred tolerance to mortalin depletion. Based upon these data, we further hypothesize that mortalin regulates the interplay between the Warburg effect and the reductive TCA cycle to facilitate cytosolic acetyl-CoA production. By extension, we predict that ACL inhibition is a promising strategy to suppress mortalin-dependent thyroid tumor cells and can be effectively combined with glycolysis inhibition. To test these hypotheses, Aim 1 will determine how ESRRA regulates mortalin transcription and examine their correlated expression and functional relationship in different thyroid tumor subtypes. Aim 2 will determine how mortalin regulates the interplay between glycolysis and the reductive TCA cycle to facilitate cytosolic acetyl-CoA production. Aim 3 will determine whether ACL is an effective target to suppress mortalin-dependent thyroid tumor cells in vitro and in vivo.

这个项目的目标是阐明在甲状腺癌中mortalin上调的机制。 确定mortalin在肿瘤细胞代谢中的作用，并评估该代谢的潜力 作为治疗靶点的吗丁啉调节的过程。新陈代谢再编程过程中的作用 能量和积木的生产对肿瘤的发展和维持至关重要，但与 有致命新陈代谢压力的风险。因此可以想象，恶性肿瘤细胞可能有 在这方面成功地制定了一种保护机制。如果被识别，这样的机制可以是 目标是在肿瘤细胞中释放死亡信号。我们之前证明了死亡蛋白的耗尽 (GRP75/HSPA9)是HSP70家族中的一种分子伴侣，可导致致命的生物能量和氧化 肿瘤细胞中的应激反应，提示mortalin上调是保护肿瘤细胞免受 代谢压力。目前对mortalin在甲状腺中的作用及其调节的了解非常有限。 癌症，这是一种代谢活跃的肿瘤。我们对TCGA RNAseq数据集的分析显示， Mortalin和ESRRA之间存在甲状腺癌特异性相关性，ESRRA是一种孤儿转录因子， 调节新陈代谢重新编程。在我们的初步研究中，ESRRA耗竭降低了死亡率 在不同的甲状腺肿瘤细胞系中表达和诱导细胞死亡，而这种杀伤力实质上是 被死亡蛋白的过度表达所废除。这些数据让我们假设ESRRA是一种肿瘤类型- 在甲状腺癌中介导mortalin过表达的特异性转录因子，以及mortalin ESRRA调节甲状腺肿瘤细胞代谢所必需。我们的代谢组分析表明 在还原TCA的背景下，Mortalin基因敲除显著耗尽乙酰-CoA及其前体 循环，同时增加乳酸和葡萄糖。此外，ATP-柠檬酸裂解酶(ACL)的耗竭 通过还原TCA循环产生的柠檬酸合成胞液乙酰-辅酶A，诱导 与死亡蛋白耗竭相似的致死效应，而丙酮酸激酶M2(PKM2)的过度表达， 产生丙酮酸的酶通常促进Warburg效应，使人对死亡耐受 耗尽。基于这些数据，我们进一步假设，mortalin调节 Warburg效应和还原的TCA循环促进胞质乙酰-CoA的产生。引申来说，我们 预测ACL抑制是一种很有前途的策略来抑制死亡蛋白依赖的甲状腺肿瘤细胞和 能有效结合糖酵解抑制作用。为了检验这些假设，目标1将决定如何 ESRRA调节mortalin转录并检测其相关表达和功能关系 在不同的甲状腺肿瘤亚型中。目标2将确定mortalin如何调节 糖酵解和还原的三氯乙酸循环促进胞浆乙酰-辅酶A的产生。目标3将决定 体外和体内ACL是否是抑制致死素依赖的甲状腺肿瘤细胞的有效靶点。