The role of the PAFc subunit Cdc73 in normal hematopoiesis and transformation

PAFc亚基Cdc73在正常造血和转化中的作用

基本信息

批准号：
9896670
负责人：
Andrew George Muntean
金额：
$ 38.29万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-04-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9896670
关键词：
Acute Acute Lymphocytic Leukemia Acute Myelocytic Leukemia Adult Affect Alleles Attenuated Biochemical Biologic Characteristic Cell Maintenance Cell Nucleus Cell physiology Cells Chemicals Chimeric Proteins Chromatin Complex DNA Data Defect Deposition Developmental Process Disease Embryo Endocrine Gland Neoplasms Epigenetic Process Exhibits Gene Expression Genes Genetic Genetic Transcription Growth Health Hematological Disease Hematopoiesis Hematopoietic Hematopoietic Neoplasms Hematopoietic stem cells Histones Human Investigation Knockout Mice Leukemic Cell Link MLL gene MLLT3 gene Malignant - descriptor Malignant Neoplasms Mammary Neoplasms Mediating Methods Methyltransferase Mixed-Lineage Leukemia Modification Molecular Molecular Probes Mus Myelogenous Nature Normal Cell Oncogenic Play Polymerase Post-Translational Protein Processing Process Proteins Regulation Regulatory Element Research Research Design Role SETDB1 gene Solid Neoplasm Suggestion Testing Therapeutic Intervention Transcriptional Activation Tumor Suppression Tumor Suppressor Proteins cancer cell cell growth fetal gene repression hematopoietic differentiation hematopoietic tissue histone methyltransferase in vivo insight knock-down leukemia leukemic transformation metaplastic cell transformation mouse model mutant novel overexpression pancreatic neoplasm progenitor programs therapeutic target

项目摘要

Epigenetic modifications of regulatory elements on chromatin profoundly impact gene expression and play a role in processes such as cellular differentiation and transformation. These post-translational modifications occur on DNA and histones and are mediated by epigenetic modifying proteins. The Polymerase Associated Factor complex (PAFc) is an epigenetic modifying complex necessary for the deposition of several epigenetic modifications associated with transcriptional activation (including H2Bub, H3K4me and H3K79me). We have recently shown that the PAFc is essential for human leukemias harboring rearrangements of the Mixed Lineage Leukemia (MLL) gene as well as several other subtypes of acute myeloid leukemia (AML). Our preliminary data shows the PAFc is also necessary for fetal hematopoiesis. Further, we found the PAFc is regulated by interaction with the H3K9 methyltransferase SETDB1, which suppresses leukemic transformation. Objective: The role of the PAFc in hematopoiesis and the distinct epigenetic functions required for cellular transformation remains unclear. Our preliminary studies have revealed a novel interaction between the PAFc and an H3K9 methyltransferase, SETDB1 and a role for the PAFc in fetal hematopoiesis. We hypothesize that the PAFc-SETDB1 interaction promotes hematopoietic differentiation and that interference of this interaction aids in transformation by promoting transcriptional activation of a gene program blocking differentiation. Specific Aims: We aim to (1) Characterize the role of the PAFc subunit, Cdc73, in hematopoiesis, (2) Validate the role of the PAFc interaction partner, SETDB1, as a hematopoietic tumor suppressor and (3) Define the mechanism by which SETDB1 modulates PAFc mediated transcriptional activation. Study Design: We have developed a mouse model that allows for the conditional deletion and subsequent characterization of the PAFc subunit, Cdc73, in adult hematopoietic tissues. We will use mutants of CDC73 that alter interaction with SETDB1, as well as overexpression and knock down to evaluate the role of SETDB1 and the PAFc-SETDB1 interaction in differentiation. We will also use a combination of biochemical, molecular and high throughput methods to query the transcriptional consequences of SETDB1 interaction with the PAFc. Health Impact: Epigenetic modifiers are recognized as critical players in cellular differentiation. They also play important roles in hematologic disease and have been validated as viable therapeutic targets. To understand processes like hematopoietic differentiation and transformation, we must define the mechanisms regulating epigenetic modifiers. As the PAFc plays a role in hematopoiesis and several diseases, the proposed research will reveal the role of a previously uncharacterized epigenetic regulator complex in hematopoiesis while also defining how protein interactions, like SETDB1, module the PAFc function during hematopoietic differentiation.

染色质调控元件的表观遗传修饰深刻影响基因表达并发挥作用在细胞分化和转化等过程中发挥作用。这些翻译后修饰发生在 DNA 和组蛋白上，并由表观遗传修饰蛋白介导。聚合酶相关因子复合物（PAFc）是一种表观遗传修饰复合物，对于多种表观遗传因子的沉积是必需的。与转录激活相关的修饰（包括 H2Bub、H3K4me 和 H3K79me）。我们有最近表明，PAFc 对于携带混合蛋白重排的人类白血病至关重要谱系白血病 (MLL) 基因以及急性髓系白血病 (AML) 的其他几种亚型。我们的初步数据显示PAFc对于胎儿造血也是必需的。此外，我们发现 PAFc 是通过与 H3K9 甲基转移酶 SETDB1 的相互作用进行调节，从而抑制白血病转化。目的：PAFc 在造血过程中的作用以及细胞所需的独特表观遗传功能转型仍不明朗。我们的初步研究揭示了 PAFc 之间的一种新颖的相互作用以及 H3K9 甲基转移酶、SETDB1 以及 PAFc 在胎儿造血中的作用。我们假设 PAFc-SETDB1 相互作用促进造血分化，并且这种相互作用的干扰通过促进阻止分化的基因程序的转录激活来帮助转化。具体目标：我们的目标是 (1) 表征 PAFc 亚基 Cdc73 在造血作用中的作用，(2) 验证 PAFc 相互作用伙伴 SETDB1 作为造血肿瘤抑制因子的作用，以及 (3) 定义 SETDB1 调节 PAFc 介导的转录激活的机制。研究设计：我们开发了一种小鼠模型，允许有条件删除和后续成人造血组织中 PAFc 亚基 Cdc73 的表征。我们将使用 CDC73 的突变体改变与 SETDB1 的相互作用，以及过表达和敲低以评估 SETDB1 的作用以及分化过程中 PAFc-SETDB1 的相互作用。我们还将结合使用生化、分子和高通量方法来查询 SETDB1 与 PAFc 相互作用的转录结果。健康影响：表观遗传修饰剂被认为是细胞分化的关键因素。他们也玩在血液疾病中发挥重要作用，并已被验证为可行的治疗靶点。要了解造血分化和转化等过程，我们必须明确调节机制表观遗传修饰剂。由于 PAFc 在造血和多种疾病中发挥作用，因此拟议的研究将揭示以前未表征的表观遗传调节复合物在造血过程中的作用，同时也定义蛋白质相互作用（如 SETDB1）如何在造血分化过程中调节 PAFc 功能。