Identifying Molecular Signatures Underlying Preleukemic Clonal Expansion

识别白血病前期克隆扩张背后的分子特征

• 批准号: 10390165
• 负责人: Charles Bramlett
• 金额: $ 3.17万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10390165
• 关键词: Address; Automobile Driving; Bar Codes; Behavior; Biological Assay; Bone Marrow Transplantation; Cells; Cellular Assay; Characteristics; Chromatin; Clonal Expansion; DNA Sequence Alteration; Data; Diagnosis; Disease; Disease Progression; Dysmyelopoietic Syndromes; Elderly; Epigenetic Process; Event; Exhibits; Gene Expression; Gene Expression Profile; Genes; Genetic; Hematologic Neoplasms; Hematological Disease; Hematopoietic; Hematopoietic System; Hematopoietic stem cells; Knock-out; Knockout Mice; Lead; Link; Malignant lymphoid neoplasm; Molecular; Molecular Profiling; Multipotent Stem Cells; Mus; Mutation; Myeloproliferative disease; Patients; Phase; Play; Population; Research Project Grants; Role; Somatic Mutation; Technology; Testing; base; bioinformatics pipeline; cell growth; experimental study; improved; insight; leukemia; mouse model; new therapeutic target; single-cell RNA sequencing; tool

Project Summary Clonal expansion occurs when the progeny of a cell excessively increases in number. It plays a crucial role in theearly phase of many hematopoietic disorders such as myeloproliferative disorders, myelodysplastic syndromes, and leukemias. During disease genesis, clonal expansion is often initiated by somatic mutations,which in turn allow the accumulation of additional molecular changes that lead to disease progression. However, not all clonal expansions lead to blood disorders or leukemia. Recent studies show that hematopoietic stem and progenitor cells (HSPCs) commonly exhibit clonal expansion after bone marrow transplantation and in healthy elderly without any apparent disease. Little is known about the differences between normal and preleukemic clonal expansion, particularly with respect to the molecular events underlying their differences. The proposed research project will address the hypothesis that preleukemic clonal expansion is associated with distinct gene expression and/or epigenetic characteristics in addition to the known leukemia-associated mutations, such as Tet2 mutations. Clonal expansion will be tracked using a genetic barcoding technology in Tet2 inducible knockout mice. Moreover, the genetic barcoding technology is integrated with droplet-based single cell RNA-sequencing (scRNA- seq) and with single cell assay for transposable accessible chromatin-sequencing (scATAC-seq) to identify molecular events that are associated with the distinct clonal expansion. The identified molecular signatures of pre-leukemic clonal expansion will be functionally tested using the dCas9-KRAB mouse model. The proposed study compares cellular expansion across different clones to identify rare cellular and molecular events associated with Tet2-induced pre-leukemic clonalexpansion. These experiments will reveal the key molecular drivers that trigger preleukemic clonal expansion undetectable using conventional assays of bulk cell populations. The findings will help improve diagnosis of hematopoietic diseases, particularly TET2 related diseases, and may identify new therapeutic targets for their treatments.

项目概要 当细胞后代数量过度增加时，就会发生克隆扩增。它扮演一个 在许多造血疾病的早期阶段发挥着至关重要的作用，例如骨髓增殖性疾病， 骨髓增生异常综合征和白血病。在疾病发生过程中，克隆扩增通常由以下因素启动： 体细胞突变，反过来又允许额外分子变化的积累，从而导致 疾病进展。然而，并非所有克隆​​扩增都会导致血液疾病或白血病。最近的 研究表明造血干细胞和祖细胞 (HSPC) 通常表现出克隆扩增 骨髓移植后和无任何明显疾病的健康老年人。鲜为人知 关于正常和白血病前期克隆扩增之间的差异，特别是在 他们差异背后的分子事件。拟议的研究项目将解决假设 白血病前期克隆扩张与不同的基因表达和/或表观遗传相关 除了已知的白血病相关突变（例如 Tet2 突变）之外，还具有其他特征。克隆 将使用 Tet2 诱导敲除小鼠中的遗传条形码技术来追踪扩增。而且， 遗传条形码技术与基于液滴的单细胞 RNA 测序（scRNA- seq）和用于转座可及染色质测序（scATAC-seq）的单细胞测定（scATAC-seq）来识别 与独特的克隆扩张相关的分子事件。已识别的分子特征 将使用 dCas9-KRAB 小鼠模型对白血病前克隆扩增进行功能测试。这 拟议的研究比较了不同克隆的细胞扩增，以识别稀有的细胞和分子 与Tet2诱导的白血病前克隆扩张相关的事件。这些实验将揭示关键 使用常规批量检测无法检测到触发白血病前期克隆扩增的分子驱动因素 细胞群。这些发现将有助于改善造血系统疾病的诊断，特别是 TET2 相关疾病，并可能为其治疗找到新的治疗靶点。