Evaluating the role of EZH2-interacting protein (EZHIP) in pediatric posterior fossa ependymoma metabolism

评估 EZH2 相互作用蛋白 (EZHIP) 在儿童后颅窝室管膜瘤代谢中的作用

• 批准号: 10231711
• 负责人: Derek Dang
• 金额: $ 3.8万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-02 至 2023-03-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10231711
• 关键词: Advisory Committees; Applications Grants; Automobile Driving; Biology; Brain region; Cancer Biology; Cell Line; Cell Proliferation; Cell Survival; Cells; Childhood; Childhood Ependymoma; Citric Acid Cycle; Clinical; Collaborations; Complex; DNA Methylation; DNA Sequence Alteration; Data; EZH2 gene; Enzymes; Ependymoma; Epigenetic Process; Exhibits; Future; Gene Expression; Genetic; Genetic Transcription; Glycolysis; Goals; Grant; Growth; Hypoxia; Impairment; In Vitro; Interruption; Knowledge; Laboratories; Link; Location; Malignant Childhood Neoplasm; Malignant Neoplasms; Mentors; Metabolic; Metabolic Pathway; Metabolism; Methods; Modeling; Molecular; Mus; Nature; Neuraxis; Outcome; Pathogenesis; Patients; Pharmacology; Posterior Fossa; Production; Prognosis; Proteins; Pyruvate Dehydrogenase Complex; Pyruvate Dehydrogenase E1; RNA Interference; RNA analysis; Recurrence; Resistance; Role; Sampling; Scientist; Solid; Testing; Therapeutic; Training; Training and Education; Treatment Efficacy; Tumorigenicity; Up-Regulation; base; cancer cell; career; cell growth; chemotherapy; effective therapy; epigenetic regulation; experimental study; genomic locus; histone methyltransferase; histone modification; in vivo; insight; knock-down; mRNA Expression; metabolomics; nerve stem cell; neuropathology; novel; novel therapeutics; overexpression; patient derived xenograft model; protein expression; pyruvate dehydrogenase; small hairpin RNA; therapeutic target; therapeutically effective; transcriptome sequencing; tumor; tumor growth; tumor metabolism

ABSTRACT Pediatric ependymomas are the third-most common malignancy of the central nervous system. While they arise in different places of the neuraxis, these tumors are most commonly seen in the posterior fossa region of the brain. Posterior fossa ependymomas have been stratified into two groups (Group A and Group B) based on DNA methylation, transcriptional, and clinical profiling. Of these two groups, Group A (also referred to as PFA) is more invasive and carries a worse prognosis. These tumors are resistant to chemotherapy and arise in sensitive locations that may render them inoperable. PFAs are unusual as more than 80% of these tumors do not bear recurrent genetic mutations. Interestingly, these tumors are defined by global loss of transcriptionally- repressive histone modification H3K27me3 and global gain of transcriptionally-activating histone modification H3K27ac. Alterations in DNA methylation and global H3K27me3 reduction indicate that PFAs are epigenetically driven. EZH2-inhibitory protein (EZHIP) is a novel protein that is expressed highly in PFAs and drives global reduction of H3K27me3 by inhibiting the activity of histone methyltransferase EZH2. It remains unknown how EZHIP expression and H3K27me3 loss drives tumorigenicity in PFA ependymomas. Strikingly, RNA-sequencing analysis of PFAs show upregulation of the pyruvate dehydrogenase complex, a key metabolic complex that links glycolysis and the TCA-cycle. Subsequent metabolomic and RNA analysis show that glycolytic and TCA-cycle metabolism are also enhanced in these tumors. Based on these preliminary data, I hypothesize that EZHIP expression upregulate PFA metabolism by epigenetically activating the pyruvate dehydrogenase complex. To test this hypothesis, I will characterize the epigenetic and metabolic effect of exogenous EZHIP expression in neuronal stem cells and EZHIP deletion in patient-derived PFA cell lines. To define the role of the PDC on tumor pathogenesis, I will target PDC expression via RNA-interference and pharmacological inhibition and determine the effect on PFA growth in vivo and in vitro. These experiments will provide novel mechanistic insights into PFA growth and will provide solid scientific data that may inform future therapeutic strategies.

抽象的 儿童室管膜瘤是中枢神经系统第三大常见恶性肿瘤。当它们出现时 在神经轴的不同部位，这些肿瘤最常见于后颅窝区域 脑。后颅窝室管膜瘤根据以下情况分为两组（A 组和 B 组）： DNA 甲基化、转录和临床分析。在这两组中，A 组（也称为 PFA） 更具侵入性并且预后更差。这些肿瘤对化疗有抵抗力并出现在 可能导致它们无法操作的敏感位置。 PFA 很不寻常，因为 80% 以上的肿瘤都是如此 不携带反复发生的基因突变。有趣的是，这些肿瘤的定义是转录的整体丧失 抑制性组蛋白修饰 H3K27me3 和转录激活组蛋白修饰的全局增益 H3K27ac。 DNA 甲基化的改变和整体 H3K27me3 的减少表明 PFA 是表观遗传的 驱动的。 EZH2抑制蛋白（EZHIP）是一种在PFA中高表达并驱动全球 通过抑制组蛋白甲基转移酶 EZH2 的活性来减少 H3K27me3。目前尚不清楚如何 EZHIP 表达和 H3K27me3 缺失驱动 PFA 室管膜瘤的致瘤性。引人注目的是，RNA测序 PFA 分析显示丙酮酸脱氢酶复合物的上调，丙酮酸脱氢酶复合物是一种关键的代谢复合物，将 糖酵解和 TCA 循环。随后的代谢组学和 RNA 分析表明，糖酵解和 TCA 循环 这些肿瘤的新陈代谢也得到增强。根据这些初步数据，我假设 EZHIP 表达通过表观遗传激活丙酮酸脱氢酶上调 PFA 代谢 复杂的。为了验证这个假设，我将描述外源 EZHIP 的表观遗传和代谢效应 神经元干细胞中的表达和患者来源的 PFA 细胞系中的 EZHIP 缺失。定义角色 PDC对肿瘤发病机制的影响，我将通过RNA干扰和药物抑制来靶向PDC的表达 并确定体内和体外对 PFA 生长的影响。这些实验将提供新的机制 深入了解 PFA 的增长，并将提供可靠的科学数据，为未来的治疗策略提供信息。