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会导致白血病的发生 骨髓增生异常综合征（MDS）和急性髓系白血病（AML）。 MDS 患者被描述为 组成性激活这些途径的突变。我们的研究表明，突变会损害 紧急（应激）粒细胞生成（EG）的终止也是一种可能的机制。 EG 的过程是 在感染挑战期间快速、间歇性粒细胞 (PMN) 的产生，是先天性粒细胞的关键组成部分 免疫反应。我们之前确定 Triad1，一种 E3 泛素 (Ub) 连接酶，对于 EG- 终止。与持续 EG 反应在白血病发生中的作用一致，我们发现 Triad1 发挥作用 作为 AML 的白血病抑制因子，增加同源域转录因子的表达。不利的 克隆性骨髓恶性肿瘤的预后子集，包括 MLL1/KMT2A 重排的 MDS/AML， 其特征是这些蛋白质组的过度表达（例如 HoxB3、B4、A9-11、Cdx1 和 2、Meis1）。 移植表达白血病相关 Mll1 融合蛋白的骨髓的小鼠在 几个月的滞后时间；表明白血病的发生还需要突变的积累 涉及 MLL1/KMT2A 重排。我们发现 Triad1 表达在白血病发生过程中下降 骨髓中表达 Mll1 融合蛋白的小鼠。我们还发现 Triad1 击倒 或 EG 发作加速了此类小鼠的 AML 发展。我们展示了 HoxA10 增强型，但 HoxA9 抑制 Triad1 基因转录。而且，Triad1 重新表达可挽救 Hoxa10-/- 小鼠中的 EG 终止。 我们进行了筛选来鉴定具有 Triad1 依赖性 Ub 的蛋白质。除了炎症介质 和 RTK，我们鉴定了参与综合应激反应的蛋白质（ISR；Gcn1、eIF2B4 和 eIF4G1）。 ISR 通过调节翻译来防止持续炎症期间的代谢耗竭和细胞死亡 纠正代谢缺陷并在缺陷得到纠正后增强增殖。 Gcn1 作为主要 通过激活 Gcn2/eIF2B4 来调节该过程。我们发现骨髓细胞中 Triad1 的敲低改变了 正在进行翻译的 mRNA 的概况。然而，这些细胞中 Triad1 和 Gcn1 的联合敲低 逆转参与细胞应激反应、细胞对 DNA 反应的 mRNA 翻译异常 Triad1 敲低导致损伤、细胞周期进展、翻译、蛋白质代谢和 ISR 终止 独自的。我们发现 Gcn1 敲除延迟了骨髓移植小鼠的 AML 发展 一种 Mll1 融合癌蛋白，并逆转了 Triad1 敲低对加速白血病发生的影响。 我们假设 Triad1 对 ISR 的抑制促进紧急粒细胞生成 (EG) 终止 并抑制 Hox 表达增加的疾病中的白血病发生。这将通过三个目标来实现。 目标 1：确定 HoxA10/Triad1 抑制 ISR 在终止紧急粒细胞生成中的作用。 将研究紧急粒细胞生成 (EG) 的小鼠模型，以了解 HoxA10/Triad1 介导的 Ub 的作用 Gcn1 参与 EG 终止、翻译组的调节以及与该过程相关的下游通路。 目标 2：确定 Hox/Triad1 的 ISR 调节对突变发生和白血病发生的影响。 使用 MLL1/KMT2A 重排、不良预后 AML 的小鼠模型，我们将研究 HoxA10/Triad1 介导的 Gcn1 Ub 对翻译组的影响以及白血病发生过程中突变的积累。 目标 3：确定 Hox/Triad1 对人类炎症途径和白血病发生的影响 MDS/AML。将研究 MDS/AML 人类受试者的骨髓和外周血 CD34+ 细胞 Hox/Triad1 表达与炎症通路激活和不良后果的关联。分子 将通过 RNA 测序、全外显子组测序和小鼠异种移植来研究机制。 目标是确定人类 MDS/AML 的分子子集，其中 Triad1/ISR 相关事件作为分子 骨髓性白血病持续炎症和突变的标志物和可能的治疗靶点。