Dissecting innate immune signaling in pre-leukemia evolution

剖析白血病前期进化中的先天免疫信号

• 批准号: 10584536
• 负责人: Iannis Aifantis
• 金额: $ 62.55万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-04 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10584536
• 关键词: Acetylation; Acute Myelocytic Leukemia; Affect; Aging; Agonist; Applications Grants; Binding; Biological Assay; Cell physiology; Cells; Clinical; DNMT3a; Data; Development; Disease; Dysmyelopoietic Syndromes; Evolution; Gene Expression; Gene Expression Profiling; Genetic; Genetic Models; Goals; Hematopoiesis; Hematopoietic; Hematopoietic Neoplasms; Hematopoietic stem cells; Human; Hypermethylation; Immune signaling; Individual; Leukemic Cell; Link; Lysine; Malignant - descriptor; Mediating; Messenger RNA; Modeling; Modification; Molecular; Mus; Mutate; Mutation; Myeloid Leukemia; Myeloproliferative disease; Oncogenic; Outcome; Pathway interactions; Patients; Phenotype; Post-Translational Protein Processing; Preleukemia; Proteins; Proteomics; RNA Splicing; RNA interference screen; Regulation; Repression; Risk; Role; Signal Transduction; TRAF6 gene; Therapeutic; Toll-like receptors; Tumor Suppressor Proteins; Ubiquitin; Ubiquitination; acute myeloid leukemia cell; disorder subtype; human disease; improved; in vivo; innate immune pathways; insight; leukemia; loss of function; mouse model; novel; promoter; protein expression; self-renewal; small hairpin RNA; stem; stem cell function; stem cells; transcriptome; tumor; ubiquitin-protein ligase

Abstract Clonal hematopoiesis (CH) is an aging associated condition characterized by the clonal outgrowth of mutated pre-leukemic cells. Although individuals with CH are healthy, they are at an increased risk of developing hematopoietic malignancies. To identify cooperating molecular alterations required for malignant transformation of clonal pre-leukemic HSPC, we performed an in vivo shRNA screen and found that shRNAs targeting Traf6 were overwhelmingly enriched in following transformation to overt myeloid leukemias. TRAF6 is an ubiquitin E3 ligase that synthesizes Lysine (K) 63-linked ubiquitin chains on substrates leading to Toll-like receptor (TLR) superfamily pathway activation. In support of our in vivo shRNA screen, promoter hypermethylation and reduced expression of TRAF6 is observed in subsets of myeloid malignancy patients, including ~40-50% of acute myeloid leukemia (AML). Moreover, our preliminary data shows that deletion of Traf6 in pre-leukemic Tet2-deficient HSPC results in an aggressive myeloid neoplasm in part through a novel MYC-dependent mechanism. Based on our findings, we hypothesize that loss of TRAF6 drives subsets of genetically-defined myeloid malignancies, specifically via a novel post-translational modification of MYC resulting in its activation. The objectives of the proposal are to uncover the molecular and cellular basis of TRAF6 deletion on pre-leukemic HSPC function with the long-term goal of uncovering improved therapeutic approaches by investigating the consequences of TRAF6 deletion in models of CH and on leukemia development (Aim 1), identifying the molecular basis of the tumor suppressor-like function of TRAF6 in AML (Aim 2), and evaluating the oncogenic potential of a novel TRAF6-dependent MYC post-translational modification (Aim 3). These studies are highly significant as they will provide critical insight into the progression of pre-leukemic states to overt leukemia as a result of subverting select innate immune pathways, describe a novel disease-modifying role of TLR-TRAF6, and reveal an unreported mechanism of MYC regulation. These studies have direct translational implications and fill an unmet clinical need for genetically- and phenotypically-defined subtypes of AML/MPN.

抽象的 克隆造血（CH）是一种相关的衰老状况，其特征是克隆生长 突变的白细胞细胞。尽管患有CH的人很健康，但他们的风险增加了 发展造血恶性肿瘤。确定所需的合作分子改变 克隆前白血病HSPC的恶性转化，我们进行了体内shRNA筛查，发现 靶向traf6的shRNA在以下转化向明显的髓样的转化中极为丰富 白血病。 TRAF6是一种泛素E3连接酶，合成赖氨酸（K）63连接的泛素链 导致Toll样受体（TLR）超家族途径激活的底物。支持我们的体内 在shRNA屏幕，启动子高甲基化和Traf6的表达降低中 髓样恶性肿瘤患者，包括约40-50％的急性髓性白血病（AML）。而且，我们的 初步数据表明，traf6缺失在白细胞前TET2缺陷HSPC中导致侵略性 髓样肿瘤部分通过一种新型的MYC依赖机制。根据我们的发现，我们 假设TRAF6的损失驱动遗传定义的髓样恶性肿瘤的子集，特别是 通过一种新型的MYC翻译后修饰，导致其激活。提案的目标 要揭示Traf6缺失的分子和细胞基础，该缺失在美氏hspc函数上 长期目标是通过研究的后果来揭示改进的治疗方法 CH和白血病开发模型中的TRAF6缺失（AIM 1），确定的分子基础 TRAF6在AML中的肿瘤抑制功能（AIM 2），并评估A的致癌潜力 新型TRAF6依赖性MYC翻译后修饰（AIM 3）。这些研究非常重要 因为它们将对美产血前国家在明显白血病的进展中提供批判性见解 颠覆精选的先天免疫途径，描述TLR-TRAF6的新型疾病改良作用，和 揭示了MYC调节的未报告机制。这些研究具有直接的翻译意义 并满足了对AML/MPN的遗传和表型定义亚型的未满足的临床需求。