Mapping the Time Course of mTORC1-Driven Tumorigenesis in the Developing Brain

绘制发育中大脑中 mTORC1 驱动的肿瘤发生的时间进程

• 批准号: 10475005
• 负责人: Laura Catherine Geben
• 金额: $ 3.4万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10475005
• 关键词: Adult; Affect; Benign; Binding Proteins; Brain; Brain Neoplasms; Cell Cycle; Cell Differentiation process; Cell Proliferation; Cell Size; Cell model; Cells; Cerebrum; Characteristics; Clinical; Complex; Custom; Cytometry; Cytostatics; Data; Development; Disease; Disease model; Dorsal; Early Diagnosis; Embryo; Embryonic Development; Etiology; Eukaryotic Initiation Factors; Event; FRAP1 gene; Flow Cytometry; Genes; Genetic Transcription; Glean; Goals; Growth; Health; Human; Image Cytometry; In Vitro; Knowledge; Lead; Magnetic Resonance Imaging; Maps; Measures; Mediator of activation protein; Microscopy; Mitotic; Mitotic Activity; Modeling; Mus; Mutate; Mutation; Neurodevelopmental Disorder; Newborn Infant; Organoids; Pathway interactions; Patients; Pattern; Pharmacology; Phosphoproteins; Phosphorylation; Phosphotransferases; Population; Positioning Attribute; Predisposition; Prevention; Process; Proteins; Regulation; Research; Research Project Grants; Resected; Ribosomal Protein S6; Role; Signal Pathway; Signal Transduction; Subependymal Giant Cell Astrocytoma; TSC2 gene; Testing; Therapeutic Intervention; Time; TimeLine; Training; Translating; Tuberous Sclerosis; Ventricular; Wild Type Mouse; Work; antibody conjugate; body system; cell growth; developmental disease; human model; in vivo; induced pluripotent stem cell; inhibitor; insight; loss of function; loss of function mutation; mTORopathies; mouse model; mutant; nerve stem cell; neurodevelopment; neurogenesis; novel; pediatric patients; perinatal development; postnatal; postnatal development; prenatal; prevent; stem cell fate; stem cell niche; subventricular zone; tumor; tumor growth; tumorigenesis; tumorigenic

SUMMARY The mammalian target of rapamycin complex 1 (mTORC1) signaling pathway regulates cell size and growth and is frequently mutated in disease, including in a class of neurodevelopmental disorders known as “mTORopathies.” One such disorder, Tuberous Sclerosis Complex (TSC), affects nearly 1 in every 6,000 newborns and is characterized by the growth of benign tumors throughout the body. TSC is caused by an inactivating mutation in the genes that encode the negative regulators of mTORC1, leading to protein loss of function, hyperactivation of mTORC1, and increased cell proliferation through phosphorylation of ribosomal protein S6 (p-S6) and eukaryotic translation initiation factor 4E-binding protein 1 (p-4EBP1). Twenty percent of TSC patients develop a large tumor that preferentially presents near the ventral region of the ventricular- subventricular zone (V-SVZ), the largest neural stem cell niche in the adult brain. Recent studies of neural stem cells in the V-SVZ revealed variable transcriptional and functional capabilities corresponding to a cell’s position along the dorsoventral axis of the V-SVZ, including differential activation of mTORC1 and susceptibility to TSC tumor formation. Further, different populations of neural stem cells in the niche are mitotically active at different times throughout pre- and postnatal neural development. Postnatally, mTORC1 has been shown to be important in regulating neural stem cell quiescence, but mTORC1 signaling in the prenatal V-SVZ and its effect on quiescence in embryonic neural stem cells has not been investigated. The goal of this project is to determine the developmental stage when differential mTORC1 activity emerges along the dorsoventral axis of the V-SVZ and the extent to which dysregulated mTORC1 signaling alters cell fate. The central hypothesis of this project is that levels of mTORC1-dependent p-4EBP1, but not p-S6, determine both a prenatal neural stem cell's mitotic activity and susceptibility to TSC tumor development. To test this hypothesis, an inducible mouse model and pharmacologic agents will be used to manipulate mTORC1 signaling during embryogenesis. To map the emergence of differences in mTORC1 activity in healthy and disease states, per-cell levels of mTORC1-dependent phosphorylation events will be quantified via imaging and flow cytometry analyses of embryonic neural stem cells. To compare results across species and platforms, mTORC1-dependent signaling will be quantified in cerebral organoid models grown from induced pluripotent stem cells derived from TSC patients. Through this project, I will build upon my prior training to evaluate cell signaling and differentiation in human and mouse models of disease. Results of this work will determine the role of mTORC1 in regulating prenatal neural stem cell fate in health and disease. Clinically, this work will provide a greater understanding of the dysregulated signaling mechanisms that lead to perinatal development of tumors in the V-SVZ and identify potential suitable time points for therapeutic interventions for patients with TSC and other mTORopathies.

总结 哺乳动物雷帕霉素靶蛋白复合物1（mTORC 1）信号通路调节细胞大小和生长 并且在疾病中经常发生突变，包括一类神经发育障碍， mTORopathies一种这样的疾病，多发性硬化症（TSC），影响近1每6000 新生儿，其特征是全身良性肿瘤的生长。TSC是由一种 失活突变的基因编码的负调控mTORC 1，导致蛋白质的损失， 功能，mTORC 1的过度活化，以及通过核糖体磷酸化增加细胞增殖， 蛋白S6（p-S6）和真核生物翻译起始因子4 E结合蛋白1（p-4 EBP 1）。的百分之二十 TSC患者发展为大肿瘤，优先出现在心室的腹侧区域附近， 脑室下区（V-SVZ）是成人大脑中最大的神经干细胞龛。神经系统的最新研究 V-SVZ中的干细胞显示了与细胞的功能相对应的可变转录和功能能力， 沿着V-SVZ的背腹轴沿着定位，包括mTORC 1的差异激活和易感性 TSC肿瘤的形成。此外，龛中的不同神经干细胞群体在24小时内具有有丝分裂活性。 在出生前和出生后的神经发育中有不同的时间。出生后，mTORC 1已被证明是 重要的调节神经干细胞的静止，但mTORC 1信号在产前V-SVZ及其影响 对胚胎神经干细胞静止的影响尚未研究。该项目的目标是 确定发育阶段时，差异mTORC 1活性出现沿着背腹轴的 V-SVZ和mTORC 1信号失调改变细胞命运的程度。的中心假设 mTORC 1依赖的p-4 EBP 1水平，而不是p-S6，决定了产前神经干 细胞的有丝分裂活性和对TSC肿瘤发展的易感性。为了验证这一假设， 模型和药理学试剂将用于在胚胎发生期间操纵mTORC 1信号传导。到 绘制健康和疾病状态下mTORC 1活性差异的出现， mTORC 1依赖性磷酸化事件将通过成像和流式细胞术分析定量， 胚胎神经干细胞为了比较不同物种和平台的结果，mTORC 1依赖性信号传导 将在从TSC衍生的诱导多能干细胞生长的脑类器官模型中定量 患者通过这个项目，我将建立在我以前的培训，以评估细胞信号和分化， 人类和小鼠疾病模型。这项工作的结果将确定mTORC 1在调节 产前神经干细胞在健康和疾病中的命运。临床上，这项工作将提供一个更好的理解， 导致V-SVZ肿瘤围产期发展的失调信号传导机制， TSC和其他mTOR病患者治疗干预的潜在合适时间点。