Dissecting the functional role of LINE1 retrotransposon-mediated interferon signaling in myeloid leukemia

剖析 LINE1 逆转录转座子介导的干扰素信号在髓系白血病中的功能作用

基本信息

批准号：
10536349
负责人：
Michael Lee
金额：
$ 3.77万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-18 至 2026-07-17
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10536349
关键词：
Ablation Acute Myelocytic Leukemia Address Adult Affect Apoptosis Biology CRISPR-mediated transcriptional activation Cell Aging Cell Cycle Arrest Cell Proliferation Clustered Regularly Interspaced Short Palindromic Repeats Complementary DNA DNA Dependence Development Double-Stranded RNA Elements Epigenetic Process Gene Expression Regulation Genetic Genetic Transcription Genetic study Genome Stability Genomic DNA Hematologic Neoplasms Hematopoiesis Hematopoietic Hematopoietic Neoplasms Human Immune Impairment In Vitro Individual Inflammation Innate Immune Response Interferon Activation Interferon Type I Interferons Jumping Genes Knockout Mice Knowledge Link Long Interspersed Elements MLL-AF9 Maintenance Malignant - descriptor Malignant Neoplasms Mediating Modeling Molecular Mus Myelogenous Myeloid Leukemia Natural Immunity Nature Nucleic Acids Pathogenesis Pathway interactions Patients RNA Reporting Repression Retrotransposition Retrotransposon Reverse Transcription Role Signal Pathway Signal Transduction Survival Rate Therapeutic Transcript Transgenic Mice Viral Work Xenograft procedure acute myeloid leukemia cell base cancer type chemotherapy clinical heterogeneity epigenetic silencing gene product in vivo inhibitor knock-down leukemia leukemia initiating cell leukemogenesis mimicry mouse model mutant novel therapeutics overexpression receptor response self-renewal sensor small hairpin RNA standard of care targeted treatment tumor tumorigenesis

项目摘要

PROJECT SUMMARY Acute myeloid leukemia (AML) is one of the most aggressive hematologic malignancies in adults, yet decades- old chemotherapies remain the standard of care and few targeted therapies exist owing to its molecular and clinical heterogeneity. An emerging hallmark of AML development is the epigenetic silencing of LINE1 retrotransposons which is required to maintain AML self-renewal, differentiation blockade, and genomic stability. Aberrant reactivation of LINE1 retrotransposons selectively impairs propagation of human and mouse AML cells without affecting normal hematopoiesis; however, it remains elusive how LINE1 activity inhibits myeloid leukemogenesis. Aberrant retrotransposon reactivation by cancer-targeting epigenetic inhibitors such as DNA hypomethylating agents (DMA) produces a type I interferon (IFN)-mediated ‘viral mimicry’ response in various cancer types, including leukemias, resulting in cell cycle arrest and apoptosis. We hypothesize that LINE1 retrotransposons contribute to the development of myeloid leukemia by modulating type I interferon signaling mediated by cGAS and/or RIG-I-like Receptor (RLR) sensing of LINE1 gene products. This proposal will establish the functional role of LINE1-mediated IFN signaling in myeloid leukemogenesis and determine the mechanisms by which LINE1 activates innate immune ‘viral mimicry’ pathways in AML cells. The Specific Aims of this proposal intend to 1) establish the functional role of LINE1-mediated interferon signaling in myeloid leukemogenesis and progression; and 2) identify the molecular sensors of LINE1-mediated interferon activation in AML. Ectopic LINE1 overexpression and CRISPR activation of endogenous LINE1s in human AML cells will determine whether LINE1 expression induces type I IFNs and impacts cell proliferation, myeloid differentiation, and/or apoptosis. Combining a conditional LINE1 activation transgenic mouse with the established MLL-AF9 retroviral leukemia model will determine whether activation of LINE1s induces hematopoietic-specific type I IFN to impair AML initiation and/or maintenance in vivo. Moreover, genetic ablation of cGAS, RIG-I, or MDA5 nucleic acid sensors individually or in combination in human AML cells and their corresponding knockout mouse models will determine how loss of DNA- and/or RNA-sensing pathways affects LINE1-induced inflammation and AML pathogenesis in vivo. Altogether, these stringent genetic studies will provide direct evidence to establish the functional role of LINE1-mediated IFN signaling in myeloid leukemia. Addressing these outstanding knowledge gaps will be critical to inform whether and how modulation of the retrotransposon-innate immunity crosstalk may be leveraged as a new mechanism-based therapeutic strategy to selectively eradicate AML cells.

项目概要急性髓系白血病（AML）是成人中最具侵袭性的血液恶性肿瘤之一，但数十年来，旧的化疗仍然是治疗标准，由于其分子和功能的原因，很少有靶向疗法存在。 AML 发展的一个新标志是 LINE1 的表观遗传沉默。逆转录转座子是维持 AML 自我更新、分化阻断和基因组稳定性所必需的。 LINE1 逆转录转座子的异常重新激活选择性损害人和小鼠 AML 细胞的增殖在不影响正常造血功能的情况下；然而，LINE1 活性如何抑制骨髓细胞仍不清楚。癌症靶向表观遗传抑制剂（例如 DNA）重新激活异常的逆转录转座子。低甲基化剂 (DMA) 在多种疾病中产生 I 型干扰素 (IFN) 介导的“病毒拟态”反应癌症类型，包括白血病，导致细胞周期停滞和细胞凋亡。逆转录转座子通过调节 I 型干扰素信号传导促进髓系白血病的发展该提案将由 LINE1 基因产物的 cGAS 和/或 RIG-I 样受体 (RLR) 感应介导。建立 LINE1 介导的 IFN 信号在骨髓性白血病发生中的功能作用并确定 LINE1 激活 AML 细胞中先天免疫“病毒拟态”途径的机制。该提案旨在 1) 确定 LINE1 介导的干扰素信号传导在骨髓中的功能作用白血病发生和进展；2) 识别 LINE1 介导的干扰素激活的分子传感器在人类 AML 细胞中异位 LINE1 过度表达和内源 LINE1 的 CRISPR 激活将确定 LINE1 表达是否诱导 I 型干扰素并影响细胞增殖、骨髓分化、和/或细胞凋亡将条件性 LINE1 激活转基因小鼠与已建立的 MLL-AF9 相结合。逆转录病毒白血病模型将确定 LINE1 的激活是否诱导造血特异性 I 型干扰素此外，cGAS、RIG-I 或 MDA5 核酸的基因消融。人类 AML 细胞及其相应的基因敲除小鼠模型中单独或组合的酸传感器将确定 DNA 和/或 RNA 传感途径的丧失如何影响 LINE1 诱导的炎症和 AML 总而言之，这些严格的遗传学研究将为确定这一点提供直接证据。 LINE1 介导的 IFN 信号传导在髓性白血病中的功能作用解决这些突出的知识。间隙对于了解逆转录转座子-先天免疫串扰是否以及如何调节至关重要可以作为一种新的基于机制的治疗策略来选择性地根除 AML 细胞。