Cohesin Mutations in Core-Binding Factor Acute Myeloid Leukemia

摘要 核心结合因子白血病代表AML的一种亚型，包括30%的儿童和15%的成人 AML。核心结合因子复合物在正常造血的调节中是必不可少的， AML 1（也称为RUNX 1）和CBFB。涉及核心结合因子的染色体改变 复合物是众所周知的白血病发展的“驱动因素”， 影响t（8;21）导致融合癌蛋白AML 1-ETO，inv（16）导致CBFB-MYH 11。 令人惊讶的是，这些突变本身不会在动物模型中诱导AML，这表明额外的“命中”是可能的。 必需的.粘着蛋白复合物的四个成员之一（SMC 1a、SMC 3、RAD 21、STAG 1）的突变是 常见于AML患者，经常（18-20%）与AML 1-ETO同时发生，但从未与 CBFB-MYH 11.这表明存在或不存在粘着蛋白突变的选择压力取决于 在驱动癌基因上。通过更多地了解这些白血病的基因组成以及额外的 突变促进白血病发生，我们可以开发靶向治疗，这将减少毒性和 与现有治疗方法相比，复发率。我们假设，粘附素突变协同 AML 1-ETO在白血病转化过程中，而粘附素突变和CBFB-MYH 11 形成一种合成的致命的相互作用。在目标1中，将用AML 1-AML 2进行体内移植研究。 ETO; SMC 3 +/+与AML 1-ETO; SMC 3 +/-相比，而CBFB-MYH 11; SMC 3 +/+和CBFB-MYH 11; SMC 3 +/-将 在体外进行研究。在目标2中，将进行分子研究，以深入研究驱动 白血病将进行ChIP测序，以确定AML 1-ETO基因组占有率的变化， cohesin haploinsufficiency。将进行ATAC-seq和RNA-seq，以确定 CBFB-MYH 11的染色质可及性和转录组由于粘连蛋白单倍不足。我们的初步 研究表明，粘附素的缺失增强了AML 1-ETO转导细胞的体外自我更新。 初步的ATAC测序表明，涉及骨髓发育的几个基序（RUNX 1， GATA 2、ERG、PU. 1）在AML 1-ETO; SMC 3 +/-背景中富集。此外，RNA测序揭示了 与SMC 3 +/+相比，AML 1-ETO; SMC 3 +/-中MYC、Rb和E2 F致癌基因特征上调。 培训潜力丰富，为未来的医生科学家在这一建议，因为它涉及使用临床 观察，以产生假设，设计研究计划，并根据观察结果开发临床相关性。 基础科学研究成果。在整个培训过程中，将很容易获得指导支持， 所有必要的设备和资源需要完成这个项目。

Abstract Core-binding factor leukemia represents a subtype of AML and encompasses 30% of pediatric and 15% of adult AMLs. The core-binding factor complex is essential in the regulation of normal hematopoiesis and is composed of AML1 (also known as RUNX1) and CBFB. Chromosomal alterations involving the core-binding factor complex are well-known “drivers” of leukemia development and have similar clinical and prognostic implications. A t(8;21) leads to the fusion oncoprotein AML1-ETO and an inv(16) leads to CBFB-MYH11. Surprisingly, these mutations alone do not induce AML in animal models, suggesting additional “hits” are required. Mutations in one of four members of the cohesin complex (SMC1a, SMC3, RAD21, STAG1) are commonly found in patients with AML and frequently (18-20%) co-occur with AML1-ETO, but never with CBFB-MYH11. This suggests a selective pressure for the presence or absence of cohesin mutations depending upon the driver oncogene. By learning more about the genetic makeup of these leukemias and how additional mutations promote leukemogenesis, we can develop targeted therapies which will reduce both toxicity and the relapse rate compared to existing treatments. We hypothesize that cohesin mutations synergize with AML1-ETO during leukemic transformation, whereas cohesin mutations and CBFB-MYH11 form a synthetic lethal interaction. In Aim 1, in vivo transplant studies will be performed with AML1- ETO;SMC3+/+ compared to AML1-ETO;SMC3+/- while CBFB-MYH11;SMC3+/+ and CBFB-MYH11; SMC3+/- will be studied in vitro. In Aim 2, molecular studies will be performed to delve into the mechanisms driving leukemia. ChIP-sequencing will be performed to identify changes in AML1-ETO genomic occupancy upon introduction of cohesin haploinsufficiency. ATAC-seq and RNA-seq will be performed to identify changes in chromatin accessibility and transcriptome of CBFB-MYH11 due to cohesin haploinsufficiency. Our preliminary studies indicate that the loss of cohesin augments in vitro self-renewal of AML1-ETO transduced cells. Preliminary ATAC-sequencing demonstrates that several motifs implicated in myeloid development (RUNX1, GATA2, ERG, PU.1) are enriched in the AML1-ETO;SMC3+/- background. Further, RNA sequencing reveals upregulation of the MYC, Rb, and E2F oncogenic gene signatures in AML1-ETO;SMC3+/- compared to SMC3+/+. Training potential abounds for a future physician scientist within this proposal as it involves using clinical observations to generate a hypothesis, design a research plan and develop clinical correlations based upon the results of basic science research. Mentoring support will be easily accessible throughout this training, as will be all necessary equipment and resources needed to complete this project.