The role of DNMT3A in gene regulation and stem cell expansion

DNMT3A 在基因调控和干细胞扩增中的作用

• 批准号: 10088421
• 负责人: Yung-Hsin Huang
• 金额: $ 9.22万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10088421
• 关键词: 1 year old; 3-Dimensional; Aberrant DNA Methylation; Affect; Basic Science; Birds; Body Regions; Body Weight; Body fat; Bone Marrow; CRISPR/Cas technology; Cell Count; DNA; DNA Methylation; DNA Modification Methylases; DNA methylation profiling; DNMT3a; Development; Disease; Doxycycline; Education; Educational workshop; Epigenetic Process; FLT3 gene; Future; Gene Expression; Gene Expression Regulation; Genes; Genome; Genomics; Goals; Hematologic Neoplasms; Hematological Disease; Hematopoietic stem cells; Homeobox Genes; Hypermethylation; Impairment; Investigation; Knowledge; Lead; Length; Light; Malignant Neoplasms; Modification; Molecular; Mus; Mutant Strains Mice; Mutate; Mutation; Pathologic; Patients; Play; Publications; Regulation; Research; Research Personnel; Resolution; Role; Sampling; Schools; Shapes; Stem Cell Development; System; The Sun; Tissues; Training Programs; Tumor Suppressor Genes; Work; anticancer research; career; career development; cell type; epigenome editing; genome-wide; genome-wide analysis; hematopoietic stem cell differentiation; histone modification; leukemia; leukemic transformation; leukemogenesis; methylome; mouse model; mutant; mutant mouse model; new therapeutic target; next generation sequencing; novel; programs; promoter; recruit; stem cell expansion; stem cells; structural genomics; three dimensional structure; tool; transcriptome; tumor; tumorigenesis

PROJECT SUMMARY DNA methylation is an epigenetic modification that plays a key role in regulating stem cells, development and many diseases. Abnormal DNA methylation has been observed in cancer for more than two decades, with many investigations focusing on promoter hypermethylation, which silences tumor suppressor genes. Additionally, DNMT3A, one of de novo DNA methyltransferases, is frequently mutated in a spectrum of hematological malignancies. Our lab has demonstrated that Dnmt3a loss impairs hematopoietic stem cell (HSC) differentiation, while expanding HSC numbers in bone marrow, suggesting DNMT3A may have a role in tumorigenesis and stem cell regulation. However, DNA methylation profiling of leukemia patient samples shows DNA methylation correlates poorly with gene expression across the genome, highlighting our limited understanding of the specific functions of DNA methylation. Recent studies using a murine model of the most frequent DNMT3A mutation in hematological malignancies, DNMT3AR882, demonstrated that DNMT3AR882 cooperates with FLT3-­ITD and NPM1c mutations to contribute to leukemic transformation. Nevertheless, our knowledge of which remaining DNMT3A mutations lead to leukemogenesis and the mechanisms by which they contribute to cancer formation remains lacking. Therefore, the long-­term goal of the proposed research is to understand how DNMT3A affects gene regulation in cancer, and how DNMT3A mutants predispose stem cell expansion. In Aim 1, I established a novel DNA epigenome editing tool (dCas9-­SunTag-­DNMT3A system) to investigate the causal relationship between DNA methylation and gene expression. Using pan-­cancer analysis of genome-­wide profiles, we have identified DNA hypermethylation occurring in the gene-­body regions of canyons (broad and undermethylated regions) with activation of corresponding gene expression. In Aim 2, using a Dnmt3a mutant murine model I developed, I will elucidate the role of one Dnmt3a mutant in priming stem cell expansion. The findings from this proposed research will shed the light on abnormal DNA methylation in cancer and molecular mechanisms of DNMT3A-­associated malignancies. Little is known about how mutations in epigenetic modifiers affect the 3D genomic structure in cancer. Therefore, in Aim 3, I plan to use my postdoctoral studies to understand how epigenetic modifiers shape the genomic landscape in cancer and their underlying mechanism. This training program is tailored to give me a comprehensive education in basic science research that will be extremely useful in achieving my long-­term career goal of becoming an independent cancer researcher.

项目摘要 DNA甲基化是一种表观遗传修饰，在调节干细胞中起关键作用， 发育和许多疾病。在癌症中已经观察到异常的DNA甲基化，以获得更多 超过二十年，许多调查重点是启动子高甲基化，这使它们保持沉默 肿瘤抑制基因。另外，从头DNA甲基转移酶之一的DNMT3A是 经常在血液系统恶性肿瘤中突变。我们的实验室证明了 DNMT3A损失会损害造血干细胞（HSC）分化，同时扩大HSC数字 骨髓，表明DNMT3A可能在肿瘤发生和干细胞调节中起作用。 但是，白血病患者样品的DNA甲基化分析显示DNA甲基化相关 基因组的基因表达很差，强调了我们对特定的有限理解 DNA甲基化的功能。最近使用最常见DNMT3A的鼠模型的研究 血液学恶性肿瘤中的突变，DNMT3AR882，证明了DNMT3AR882合作 使用FLT3-ITD和NPM1C突变有助于白血病转化。尽管如此，我们的 其余DNMT3A突变的知识导致了白血病和通过 他们对癌症形成的贡献仍然缺乏。因此，长期目标 拟议的研究是了解DNMT3A如何影响癌症的基因调节，以及如何影响 DNMT3A突变体易感干细胞膨胀。在AIM 1中，我建立了一个新颖的DNA表观基因组 编辑工具（DCAS9-Suntag-DNMT3A系统）研究DNA之间的因果关系 甲基化和基因表达。使用全基因组概况的泛伴侣分析，我们有 鉴定出在峡谷基因体区域发生的DNA高甲基化（宽和 甲基化区域），激活相应的基因表达。在AIM 2中，使用 我开发的DNMT3A突变鼠模型，我将阐明一个DNMT3A突变体在启动中的作用 干细胞膨胀。这项拟议的研究的发现将使异常DNA的灯光解散 DNMT3A相关恶性肿瘤的癌症和分子机制中的甲基化。几乎没有 知道表观遗传修饰剂中的突变如何影响癌症的3D基因组结构。 因此，在AIM 3中，我计划使用我的博士后研究来了解表观遗传修饰剂 塑造癌症及其潜在机制中的基因组景观。该培训计划是 量身定制的是为我提供基础科学研究的全面教育，这将非常有用 在实现我成为一名独立癌症研究员的长期职业目标方面。