Molecular mechanisms of drug resistance and disease progression in acute myeloid leukemia.

急性髓系白血病耐药和疾病进展的分子机制。

• 批准号: 10698907
• 负责人: Elizabeth Ann Eklund
• 金额: --
• 依托单位: JESSE BROWN VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10698907
• 关键词: AML/MDS; Acceleration; Acute Myelocytic Leukemia; Amino Acids; Anti-Inflammatory Agents; Bone Marrow; Bone Marrow Transplantation; CD34 gene; Cell Cycle Progression; Cell Death; Cells; Chimeric Proteins; Chromosomes; Clinical; Clinical Research; DNA Damage; Defect; Development; Disease; Disease Progression; Drug resistance; Dysmyelopoietic Syndromes; Emergency Situation; Event; FLT3 gene; Fusion Oncogene Proteins; Genes; Genetic Transcription; Goals; Granulopoiesis; Hematopoietic stem cells; Human; Impairment; Inflammasome; Inflammation; Inflammation Mediators; Inflammatory; Innate Immune Response; MLL gene; Mediating; Messenger RNA; Metabolic; Modeling; Molecular; Mus; Mutagenesis; Mutation; Myeloid Cells; Myeloid Leukemia; Myeloproliferative disease; Oncoproteins; Pathway interactions; Patients; Phosphorylation; Physiological; Polyribosomes; Process; Production; Prognosis; Proliferating; Protein Biosynthesis; Proteins; Proteomics; RNA metabolism; Receptor Protein-Tyrosine Kinases; Regulation; Repression; Ribosomes; Role; Site; Stress; Time; Transfer RNA; Translations; Transplantation; Twin Multiple Birth; Twin Studies; Tyrosine Phosphorylation; Ubiquitin; Xenograft procedure; adverse outcome; biological adaptation to stress; comparison control; density; exhaustion; exome sequencing; granulocyte; homeodomain; human subject; immunoregulation; knock-down; leukemia; leukemogenesis; mRNA Translation; molecular marker; molecular subtypes; mouse model; overexpression; peripheral blood; prevent; protein expression; protein metabolism; response; stem; stem cells; therapeutic target; transcription factor; transcriptome sequencing; translatome; transplant model; ubiquitin-protein ligase

Aberrant activation of the innate immune response is hypothesized to contribute to leukemogenesis in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Patients with MDS were described with mutations that constitutively activated such pathways. Our studies suggested that mutations which impair termination of emergency (stress) granulopoiesis (EG) are also a possible mechanism. EG is the process for rapid, episodic granulocyte (PMN) production during infectious challenge and a key component of the innate immune response. We previously determined that Triad1, an E3 ubiquitin (Ub) ligase, was essential for EG- termination. Consistent with a role for a sustained EG response in leukemogenesis, we found Triad1 functioned as a leukemia suppressor for AML with increased expression of homeodomain transcription factors. An adverse prognosis subset of clonal myeloid malignancies, including MDS/AML with MLL1/KMT2A rearrangements, is characterized by overexpression of a group of these proteins (e.g HoxB3, B4, A9-11, Cdx1 and 2, Meis1). Mice transplanted with bone marrow expressing leukemia-associated Mll1-fusion proteins develop AML after a lag time of months; suggesting leukemogenesis requires accumulation of mutations in addition to those involving MLL1/KMT2A-rearrangement. We found Triad1 expression decreased during leukemogenesis in a mice with expression of an Mll1-fusion protein in the bone marrow. We also found that either Triad1 knockdown or EG episodes accelerated AML development in such mice. We demonstrated HoxA10 enhanced, but HoxA9 repressed, Triad1 gene transcription. And, Triad1 re-expression rescued EG termination in Hoxa10-/- mice. We performed a screen to identify proteins with Triad1-dependent Ub. In addition to inflammatory mediators and RTKs, we identified proteins involved in the integrated stress response (ISR; Gcn1, eIF2B4 and eIF4G1). The ISR prevents metabolic exhaustion and cell death during sustained inflammation by modulating translation to correct metabolic defects and enhance proliferation once defects are corrected. Gcn1 functions as a primary regulator of this process by activating Gcn2/eIF2B4. We found Triad1-knockdown in myeloid cells altered the profile of mRNAs undergoing translation. However, combined knockdown of Triad1 and Gcn1 in these cells reversed abnormalities in translation of mRNAs involved in cellular response to stress, cellular response to DNA damage, cell cycle progression, translation, protein metabolism and ISR termination with Triad1 knockdown alone. We found Gcn1 knockdown delayed AML development in mice transplanted with bone marrow expressing an Mll1-fusion oncoprotein, and reversed the effect of Triad1-knockdown on accelerating leukemogenesis. We hypothesize that inhibition of the ISR by Triad1 facilitates emergency granulopoiesis (EG)-termination and suppresses leukemogenesis in disorders with increased Hox expression. This will be pursued by 3 Aims. Aim 1: Define the role of ISR inhibition by HoxA10/Triad1 in terminating emergency granulopoiesis. Murine models of emergency granulopoiesis (EG) will be studied for the role of HoxA10/Triad1-mediated Ub of Gcn1 in EG termination, the modulation of the translatome, and downstream pathways relevant to this process. Aim 2: Identify the influence of ISR regulation by Hox/Triad1 on mutagenesis and leukemogenesis. Using the murine models of MLL1/KMT2A rearranged, adverse prognosis AML, we will study the impact of HoxA10/Triad1-mediated Ub of Gcn1 on the translatome and accumulation of mutations during leukemogenesis. Aim 3: Determine the impact of Hox/Triad1 on inflammatory pathways and leukemogenesis in human MDS/AML. Bone marrow and peripheral blood CD34+ cells from human subjects with MDS/AML will be studied for association of Hox/Triad1 expression with inflammatory pathway activation and adverse outcomes. Molecular mechanisms will be investigated by RNA-Seq, whole exome sequencing and in murine xenografts. The goal is to identify a molecular subset of human MDS/AML with Triad1/ISR related events as molecular markers and possible therapeutic targets for sustained inflammation and mutagenesis in myeloid leukemia.

假设先天免疫反应的异常激活有助于白血病 骨髓增生综合征（MDS）和急性髓样白血病（AML）。描述了MD的患者 组成性激活此类途径的突变。我们的研究表明，损害的突变 终止紧急（压力）粒状剂（例如）也是一种可能的机制。例如 在传染性挑战期间的快速，情节粒细胞（PMN）生产和先天的关键组成部分 免疫反应。我们先前确定Triad1是E3泛素（Ub）连接酶，对于EG-至关重要 终止。与在白血病中持续EG反应的作用一致，我们发现Triad1功能正常 作为AML的白血病抑制剂，同源域转录因子的表达增加。不利 克隆髓样恶性肿瘤的预后子集，包括具有MLL1/KMT2A重排的MDS/AML 以这些蛋白质的过表达为特征（例如Hoxb3，B4，A9-11，CDX1和2，Meis1）。 用表达白血病相关的MLL1融合蛋白移植的小鼠在 几个月的滞后时间；暗示白血病需要除了那些之外积累突变 涉及MLL1/KMT2A重新制度。我们发现在白血病中，三合会的表达在A中降低 在骨髓中表达MLL1融合蛋白的小鼠。我们还发现要么Triad1敲除 或EG发作加速了此类小鼠的AML发育。我们证明了Hoxa10增强了，但是Hoxa9 抑制，三合会基因转录。并且，Triad1重新表达了Hoxa10 - / - 小鼠中的EG终止。 我们进行了一个屏幕以鉴定具有Triad1依赖性UB的蛋白质。除了炎症介体 和RTK，我们确定了参与综合应力反应的蛋白质（ISR； GCN1，EIF2B4和EIF4G1）。 ISR通过调节翻译来防止持续炎症期间的代谢疲惫和细胞死亡 一旦纠正缺陷，纠正代谢缺陷并增强增殖。 GCN1充当主要 通过激活GCN2/EIF2B4的调节器。我们发现髓样细胞中的triad1-敲低改变了 经过翻译的mRNA曲线。但是，这些细胞中的三合会和gcn1的结合敲低 在涉及胁迫的细胞反应的mRNA翻译中反转异常，细胞对DNA的反应 损伤，细胞周期进程，翻译，蛋白质代谢和ISR终止，triad1敲低 独自的。我们发现用骨髓表达移植的小鼠中的GCN1敲低延迟AML发育 MLL1融合癌蛋白，并逆转了Triad1敲低对加速性白血病发生的影响。 我们假设Triad1对ISR的抑制促进了紧急粒子（EG）末端 并抑制HOX表达增加的疾病中的白血病。这将由3个目标追求。 AIM 1：定义Hoxa10/Triad1抑制ISR抑制作用在终止紧急颗粒中的作用。 将研究紧急粒状菌（EG）的鼠模型，以hoxa10/triad1介导的UB的作用 EG终止中的GCN1，翻译组的调制以及与此过程相关的下游途径。 AIM 2：确定HOX/Triad1对ISR调节的影响，对诱变和白血病发生。 使用MLL1/KMT2A的鼠模型重新排列，不良预后AML，我们将研究 Hoxa10/Triad1介导的GCN1的UB在白血病发生过程中的转换和突变积累。 AIM 3：确定HOX/Triad1对人类炎症途径和白血病的影响 MDS/AML。将研究来自MDS/AML的人类受试者的骨髓和外周血CD34+细胞 HOX/Triad1表达与炎症途径激活和不良结果的关联。分子 RNA-Seq，整个外显子组测序和鼠异种移植物将研究机制。 目的是将人类MDS/AML的分子子集与Triad1/ISR相关事件作为分子 标志物和可能的治疗靶标，用于髓样白血病中持续炎症和诱变。