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：
10408678
负责人：
Andrew George Muntean
金额：
$ 38.24万
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 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10408678
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.

调节元素对染色质的表观遗传修饰深远影响基因表达并发挥作用在细胞分化和转化等过程中的作用。这些翻译后修改发生在DNA和组蛋白上，并通过表观遗传修饰的蛋白质介导。相关的聚合酶因子复合物（PAFC）是一种表观遗传修饰复合物，用于沉积几种表观遗传学与转录激活相关的修改（包括H2BUB，H3K4ME和H3K79ME）。我们有最近表明，PAFC对于携带混合的重排的人类白血病至关重要谱系白血病（MLL）基因以及其他几种急性髓样白血病（AML）的亚型。我们的初步数据表明，PAFC对于胎儿造血作用也是必需的。此外，我们发现PAFC是由与H3K9甲基转移酶SETDB1相互作用的调节，这抑制了白血病转化。目的：PAFC在造血和细胞所需的明显表观遗传功能中的作用转换仍然不清楚。我们的初步研究揭示了PAFC之间的新型相互作用以及H3K9甲基转移酶，setDB1和PAFC在胎儿造血中的作用。我们假设这一点 PAFC-setDB1相互作用促进了造血分化，这种相互作用的干扰通过促进基因程序阻断分化的基因程序的转录激活来帮助转化。具体目的：我们旨在（1）表征PAFC亚基Cdc73在造血中的作用，（2）验证 PAFC相互作用伙伴SETDB1作为造血肿瘤抑制剂的作用，（3）定义 SETDB1调节PAFC介导的转录激活的机制。研究设计：我们开发了一种鼠标模型，该模型允许有条件的删除和随后的删除成人造血组织中PAFC亚基CDC73的表征。我们将使用CDC73的突变体这改变了与setDB1的相互作用，以及过表达和敲门以评估setDB1的作用以及分化中的PAFC-SETDB1相互作用。我们还将结合生化，分子和高吞吐量方法，以查询SETDB1与PAFC相互作用的转录后果。健康影响：表观遗传修饰剂被认为是细胞分化的关键参与者。他们也玩在血液学疾病中的重要作用，已被验证为可行的治疗靶标。理解造血分化和转化等过程，我们必须定义调节的机制表观遗传修饰符。由于PAFC在造血和几种疾病中发挥作用，因此拟议的研究将揭示先前未表征的表观遗传调节剂在造血的作用，同时也定义蛋白质相互作用（例如setDB1）如何在造血分化过程中模块的PAFC功能。