Hematopoietic Signaling Pathway Mechanism in a GATA Factor-Dependent Network

在人类GATA2基因座上，两个不同的顺式元件（+9.5和-77）的破坏会引发免疫缺陷、骨髓增生异常综合征和/或急性髓系白血病。为了确定重要的GATA-2靶基因，我们实施了基于序列和分子标准的多组学优先排序策略。其中，GATA-2调控了无菌α Motif(SAM) Domain 14 （Samd14）的表达。机制研究证实，Samd14（以及gata -2占据的Samd14增强子（Samd14- enh））促进造血干细胞/祖细胞（HSPC）功能，促进成人造血再生，是严重贫血患者生存所必需的。Samd14-Enh通过致癌的SCF/c-Kit途径促进细胞信号传导，从而获得生存。Samd14促进SCF/c-Kit信号传导和造血祖细胞功能的关键机制尚不清楚。贫血激活的Gata2和Samd14转录依赖于增强子，这为定义再生中的GATA-2和贫血激活基因网络奠定了基础，其中涉及许多有趣的和未研究的网络成分。利用COBRE在UNMC赞助的设施，并与COBRE项目负责人合作，这些目标将严格确定Samd14如何促进SCF/c-Kit信号传导（Aim 1），新的sam结构域基因的造血功能（Aim 2），以及Samd14在造血环境中的功能（Aim 3）。拟议的项目与“内布拉斯加州分子靶点发现和开发中心”的总体使命高度相关。我们将定义全新的分子机制来调节一个完整的致癌细胞信号通路（SCF/c-Kit），以确定治疗靶点。项目负责人合作，COBRE核心提供的资源，以及科学/职业指导的支持，将极大地增强科学发现的影响和竞争r01级资金的成功。

At the human GATA2 locus, disruption of two distinct cis-elements (+9.5 and -77) instigate immunodeficiency,myelodysplastic syndrome and/or acute myeloid leukemia. To define essential GATA-2 target genes, we implemented a multi-omics prioritization strategy based on sequence and molecular criteria. Among others, this analysis revealed GATA-2 regulation of Sterile Alpha Motif(SAM) Domain 14 (Samd14) expression. Mechanistic studies established that Samd14 (and the GATA-2-occupied Samd14 enhancer (Samd14-Enh)) promotes hematopoietic stem/progenitor cell (HSPC) function, facilitates regeneration in adult hematopoiesis, and is required for survival in severe anemia. Samd14-Enh promotes cell signaling through the oncogenic SCF/c-Kit pathway, conferring survival. The key mechanisms whereby Samd14 promotes SCF/c-Kit signaling and hematopoietic progenitor function are not understood. Anemia-activated Gata2 and Samd14 transcription is enhancer-dependent, establishing a foundation for defining a GATA-2 and anemia-activated gene network in regeneration, involving many intriguing and unstudied network constituents. Utilizing COBRE-sponsored facilities at UNMC and collaborations with COBRE program leaders, these aims will rigorously establish how Samd14 promotes SCF/c-Kit signaling (Aim 1), the hematopoietic function of a new SAM-domain containing gene (Aim 2), and the function of Samd14 in hematopoietic contexts (Aim 3). The proposed project is highly relevant to the overall mission of the “Nebraska Center for Molecular Target Discovery and Development”. We will define completely novel molecular mechanisms regulating an integral, oncogenic cell signaling pathway (SCF/c-Kit) with the goal of identifying therapeutic targets. The combination of Project Leader collaborations, resources provided by COBRE Cores, and the support of scientific/career mentorship will greatly enhance the impact of scientific discoveries and success of competing for R01-level funding.