The Role of SKIDA1 in Acute Myeloid Leukemia Initiation and Maintenance

SKIDA1 在急性髓系白血病发生和维持中的作用

• 批准号: 10606263
• 负责人: Jonny Mendoza-Castrejon
• 金额: $ 3.36万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10606263
• 关键词: Acute Myelocytic Leukemia; Adult; Age; Alleles; Binding; Biological Assay; Blood Cells; Cell Line; Cells; ChIP-seq; Childhood; Childhood Acute Myeloid Leukemia; Childhood Leukemia; Chimeric Proteins; Chromatin; Chromosomal translocation; Co-Immunoprecipitations; Collecting Cell; Data; Dependence; Development; Doxycycline; Embryo; Enhancers; Frequencies; Gene Expression; Genes; Genetic Enhancer Element; Genetic Transcription; Genetic study; Genome; Goals; Hematopoiesis; Hematopoietic System; Hematopoietic stem cells; Human; Infant; Infant Leukemia; Knockout Mice; Life; Link; LoxP-flanked allele; MLL gene; MLL-AF9; Maintenance; Maps; Mixed-Lineage Leukemia; Monitor; Mus; Mutation; Neonatal; Neonatal Leukemia; Pattern; Preleukemia; Retroviridae; Role; Testing; Transplantation; Work; acute myeloid leukemia cell; adult leukemia; age related; cellular transduction; conditional knockout; driver mutation; experimental study; innovation; leukemia; leukemogenesis; loss of function; mouse genetics; mouse model; neonate; novel; novel therapeutics; postnatal; progenitor; programs; promoter; response; self-renewal; single-cell RNA sequencing; targeted treatment; transcriptome; transcriptome sequencing

ABSTRACT Chromosomal translocations involving the MLL1 gene often drive infant acute myeloid leukemia (AML). MLL fusion proteins (e.g., MLL-ENL, MLL-AF9, MLL-AF10) activate self-renewal programs in hematopoietic stem and progenitor cells, ultimately leading to transformation. The high frequency of MLL1 rearrangements in infant leukemias suggests that neonatal progenitors are uniquely poised to transform in response to these mutations. Indeed, we have recently shown that MLL-ENL initiates AML more efficiently in neonatal progenitors than in adult progenitors. This raises the question of whether MLL-ENL induces key effectors of transformation more efficiently in neonatal progenitors than in adult progenitors. We identified Ski/Dach Domain Containing 1 (Skida1) as a gene that is highly induced by MLL-ENL in neonatal, but not adult hematopoietic progenitors. SKIDA1 is also highly expressed in human pediatric MLL1 rearranged AML. Expression is largely restricted to leukemias with MLL1 rearrangements. To test whether Skida1 promotes leukemogenesis, we generated a germline loss-of-function mouse allele. Skida1 deletion by itself had negligible effects on normal hematopoiesis, consistent with the lack of expression in normal hematopoietic progenitors. Furthermore, Skida1 deletion did not affect normal HSC function. However, when we induced MLL-ENL expression in Skida1-/- neonates, we observed near complete loss of HSCs and a severe reduction in lineage committed hematopoietic progenitor cells (HPCs). Thus, Skida1-dependence emerges as a consequence of MLL-ENL expression. Next, we generated a conditional loss-of-function mouse allele. Skida1 conditional deletion in the hematopoietic system did not perturb normal hematopoiesis at any age. We are currently crossing the conditional Skida1 mouse to our MLL-ENL mouse model to test whether Skida1 promotes leukemogenesis in the context of MLL-ENL-expressing progenitors. Thus, I hypothesize that Skida1 sustains pre-leukemic HSCs and HPCs and promotes AML during neonatal stages of life. Aim 1 will use a Skida1 conditional knockout mouse to interrogate how Skida1 sustains MLL-ENL-expressing HSCs and HPCs. I will also test whether Skida1 is necessary to maintain fully transformed AML cells. Aim 2 builds upon Aim 1 by adding mechanistic studies to identify Skida1-dependent changes in gene expression and cell fate. I will test whether SKIDA1 binds chromatin to regulate leukemogenesis, and I will identify SKIDA1 binding partners. The aims of this proposal will evaluate SKIDA1 as a potential link between age-specific transcriptional programs and AML initiation, as well as offer a novel therapeutic vulnerability for treating infant leukemia.

摘要 涉及MLL 1基因的染色体易位通常会导致婴儿急性髓细胞白血病（AML）。MLL 融合蛋白（例如，MLL-ENL、MLL-AF 9、MLL-AF 10）激活造血干细胞中的自我更新程序 和祖细胞，最终导致转化。婴儿MLL 1基因重排的高频率 白血病表明新生儿祖细胞具有独特的能力来响应这些突变而发生转化。 事实上，我们最近已经证明，MLL-ENL在新生儿祖细胞中启动AML的效率比在新生儿祖细胞中更高。 成年祖先这就提出了一个问题，即MLL-ENL是否能诱导更多的转化关键效应子。 在新生祖细胞中比在成年祖细胞中更有效。我们确定了Ski/Dach结构域包含1 （Skida 1）是新生儿造血祖细胞中受MLL-ENL高度诱导的基因，但在成人造血祖细胞中不受诱导。 SKIDA 1在人类儿科MLL 1重排AML中也高度表达。表达主要限于 MLL 1重排的白血病。为了测试Skida 1是否促进白血病发生，我们生成了一个 生殖系功能丧失小鼠等位基因。Skida 1缺失本身对正常人的影响可以忽略不计。 在正常造血祖细胞中缺乏表达，这与正常造血祖细胞中缺乏表达一致。此外，委员会认为， Skida 1基因缺失不影响正常HSC功能。然而，当我们诱导MLL-ENL表达时， 在Skida 1-/-新生儿中，我们观察到HSC几乎完全丧失， 造血祖细胞（HPC）。因此，Skida 1依赖性是MLL-ENL的结果 表情接下来，我们产生了条件性功能丧失小鼠等位基因。Skida 1条件删除 造血系统在任何年龄均不干扰正常造血。我们目前正在穿越 条件性Skida 1小鼠与我们的MLL-ENL小鼠模型进行比较，以测试Skida 1是否促进白血病发生 MLL-ENL表达祖细胞的背景。因此，我假设Skida 1维持白血病前HSC 和HPC，并在新生儿阶段促进AML。Aim 1将使用Skida 1条件性击倒 研究Skida 1如何维持表达MLL-ENL的HSC和HPC。我还将测试 Skida 1是维持AML细胞完全转化所必需的。目标2是在目标1的基础上增加了 研究确定Skida 1依赖的基因表达和细胞命运的变化。我将测试SKIDA 1是否 结合染色质来调节白血病的发生，我将确定SKIDA 1的结合伙伴。其目的是 一项提案将评估SKIDA 1作为年龄特异性转录程序和AML之间的潜在联系 启动，以及提供一种新的治疗脆弱性治疗婴儿白血病。