Determining the effect of DNMT3A loss on the competitive fitness of mutant cells in somatic mosaicism

确定 DNMT3A 缺失对体细胞嵌合突变细胞竞争适应性的影响

基本信息

批准号：
10603960
负责人：
Sarah Marie Waldvogel
金额：
$ 4.71万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-12-20 至 2026-12-19
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10603960
关键词：
Address Adipocytes Affect Apoptosis Biology Blood Cell Culture System Cell Differentiation process Cell Line Cells Childhood Chimera organism DNA Modification Methylases DNMT3a DNMT3a mutation Development Developmental Gene Disadvantaged Disease Drug or chemical Tissue Distribution ES Cell Line Embryo Embryonic Development Environment Epigenetic Process Epithelium Exhibits Failure Flow Cytometry Fluorescence-Activated Cell Sorting Future Gene Cluster Gene Mutation Genes Genetic Counseling Germ Layers Goals Growth Hematopoietic stem cells Heterozygote Human Human body Image Cytometry In Vitro Individual Inherited Intellectual functioning disability Intestines Knock-out Knockout Mice Knowledge Location Loss of Heterozygosity LoxP-flanked allele Malignant Neoplasms Medical center Medicine Mesenchymal Messenger RNA Methylation Microinjections Modeling Mosaicism Mus Mutation Neurons Organism Parents Pathogenesis Pathologic Patient Care Patients Pediatric Oncologist Phenotype Population Predisposition Proteins Rahman Syndrome Recurrence Reporter Research Risk Role Sampling Scientist Seizures Seminal Shapes Somatic Mutation Syndrome System Technology Testing Texas Tissues Training blastomere structure cancer predisposition career cell type clinical care college constitutive expression design developmental disease differential expression embryo cell embryonic stem cell fitness in vivo insight intestinal epithelium leukemia loss of function loss of function mutation mRNA Differential Displays mosaic mouse model mutant neural novel overexpression pediatrician postnatal public health relevance self-renewal stem cell population stem cells success transcriptome sequencing trend

项目摘要

PROJECT SUMMARY/ABSTRACT Epigenetic dysregulation is a shared mechanism of many developmental disorders. One such disorder, Tatton-Brown-Rahman Syndrome (TBRS), results from heterozygous mutations in the de novo DNA methyltransferase, DNMT3A. TBRS is characterized by intellectual disability, seizures, overgrowth, multiple developmental abnormalities, and a predisposition to various malignancies. Since its 2014 discovery, more than 200 patients with TBRS have been identified. In the blood, patients with TBRS exhibit decreased methylation at developmental gene clusters, and abnormal tissue development in patients with TBRS results in numerous lifelong complications. However, a major gap in knowledge is that the mechanism by which DNMT3A regulates development of non-hematopoietic tissues remains unknown. Our lab has identified two individuals who exhibit a mixture of wild-type and DNMT3A-mutant cells throughout their bodies, such that they are constitutive mosaics. The distribution of mutant cells is highly variable across their tissues, and concomitant analysis of wild-type and mutant cells reveals methylation differences that suggest a role of DNMT3A in tissue development. We hypothesize that DNMT3A wild-type and mutant cells have distinct propensities to form different tissues when directly competed with one another. Understanding which tissues are favored by mutant cells in somatic mosaics will lend insight into the pathogenesis of TBRS. To test our central hypothesis, I have established a novel mouse model of somatic mosaicism. I will use this mouse and an in vitro cell culture system to address two aims: 1) I will investigate the effect of Dnmt3a loss on the differentiation capacity of specific stem cell populations, and 2) I will investigate the downstream contribution of Dnmt3a-mutant versus wild-type cells to post-natal mouse tissues. Our long-term goal is to identify tissues in which DNMT3A loss confers a selective advantage or disadvantage and to explore the mechanism of this differential tissue composition. The project is designed to prepare me for a career as an academic pediatric oncologist specializing in inherited developmental and cancer predisposition syndromes. The Goodell lab has made seminal discoveries in DNMT3A biology and has a long track-record of successful MSTP trainees. The collaborative training environment at Baylor College of Medicine, with its state-of-the-art technology cores and prime location in the Texas Medical Center will facilitate the success of this project. In the future, the results of these studies may inform the clinical care of patients with TBRS by identifying tissues in which a DNMT3A mutation is poorly tolerated. The studies may also help to inform genetic counselling of parents of patients with TBRS about their risk of recurrence by characterizing expansion or depletion of DNMT3A-mutant cells in gonadal tissues. Finally, these results will expand our understanding of how mutant cells that appear in early embryogenesis compete with wild-type cells to shape normal and disordered development.

项目概要/摘要表观遗传失调是许多发育障碍的共同机制。一种这样的疾病，塔顿-布朗-拉曼综合征 (TBRS)，由 DNA 从头突变引起甲基转移酶，DNMT3A。 TBRS 的特点是智力障碍、癫痫发作、过度生长、多发性发育异常，以及各种恶性肿瘤的易感性。自 2014 年发现以来，超过已确定 200 名 TBRS 患者。在血液中，TBRS 患者表现出甲基化水平降低 TBRS 患者的发育基因簇和组织发育异常导致许多终生并发症。然而，一个主要的知识空白是 DNMT3A 的调节机制非造血组织的发育仍然未知。我们的实验室已经确定了两个人表现出其体内野生型和 DNMT3A 突变细胞的混合物，因此它们是组成型嵌合体。突变细胞的分布在其组织中变化很大，并且对野生型和野生型细胞进行伴随分析突变细胞揭示了甲基化差异，表明 DNMT3A 在组织发育中的作用。我们假设 DNMT3A 野生型和突变型细胞具有形成不同组织的不同倾向当彼此直接竞争时。了解体细胞突变细胞青睐哪些组织马赛克将有助于深入了解 TBRS 的发病机制。为了检验我们的中心假设，我建立了一种新型的体细胞镶嵌小鼠模型。我会用这只小鼠和体外细胞培养系统旨在实现两个目标：1）我将研究 Dnmt3a 丢失的影响关于特定干细胞群的分化能力，2）我将研究下游 Dnmt3a 突变体与野生型细胞对出生后小鼠组织的贡献。我们的长期目标是确定 DNMT3A 缺失赋予选择性优势或劣势的组织，并探索其机制这种不同的组织成分。该项目旨在帮助我为学术儿科的职业生涯做好准备专门研究遗传性发育和癌症易感综合症的肿瘤学家。古德尔实验室有在 DNMT3A 生物学领域取得了开创性的发现，并拥有成功 MSTP 学员的长期记录。这贝勒医学院的协作培训环境，拥有最先进的技术核心和德克萨斯医疗中心的黄金地段将有助于该项目的成功。未来，结果这些研究可以通过识别 DNMT3A 存在的组织来为 TBRS 患者的临床护理提供信息突变的耐受性较差。这些研究还可能有助于为患有此类疾病的患者父母提供遗传咨询信息。 TBRS 通过表征性腺中 DNMT3A 突变细胞的扩增或耗竭来了解其复发风险组织。最后，这些结果将扩大我们对早期突变细胞如何出现的理解。胚胎发生与野生型细胞竞争以形成正常和无序的发育。