Cohesin Mutations in Core-Binding Factor Acute Myeloid Leukemia

摘要 核心结合因子白血病是急性髓细胞白血病的一种亚型，30%的儿童和15%的成人 AMLS。核心结合因子复合体在正常的造血调节中是必不可少的，它由 AML1(也称为RUNX1)和Cbfb。涉及核心结合因子的染色体改变 复合体是白血病发展的众所周知的“驱动力”，具有相似的临床和预后 这意味着什么。T(8；21)导致融合癌蛋白AML1-ETO，inv(16)导致Cbfb-MYH11。 令人惊讶的是，这些突变本身并不能在动物模型中诱发急性髓系白血病，这表明还有更多的“成功” 必填项。粘附素复合体的四个成员之一(SMC1a、SMC3、RAD21、STAG1)的突变是 常见于AML患者，常(18%-20%)与AML1-ETO同时发生，但从未与AML1-ETO同时发生 Cbfb-MYH11.这表明存在或不存在凝集素突变的选择性压力取决于 对致癌基因的影响。通过了解更多关于这些白血病的基因构成以及如何增加 突变促进白血病的发生，我们可以开发有针对性的治疗方法，从而降低毒性和 与现有治疗方法相比的复发率。我们假设粘附素突变与 AML1-ETO在白血病转化中的作用，而粘附素突变和Cbfb-MYH11 形成一种人工合成的致命的相互作用。在目标1中，体内移植研究将使用AML1- ETO；SMC3+/+与AML1-ETO比较；SMC3+/-而Cbfb-MYH11；SMC3+/+和Cbfb-MYH11；SMC3+/-将 在体外进行研究。在目标2中，将进行分子研究，以深入探讨驱动 白血病。将进行芯片测序，以确定AML1-ETO基因组占有率的变化 引入粘附素单倍体功能不全。将执行atac-seq和rna-seq以确定 Cbfb-MYH11由于粘附素单倍体不足而染色质可及性和转录组。我们的预赛 研究表明，粘附素的丢失促进了AML1-ETO转导细胞的体外自我更新。 初步的ATAC-测序表明，几个基序与髓系发育有关(RUNX1， GATA2、ERG、PU.1)富含AML1-ETO；SMC3+/-背景。此外，RNA测序揭示了 与SMC3+/+相比，AML1-ETO；SMC3+/-中MYC、Rb和E2F癌基因信号上调。 在这项提议中，对未来的内科科学家来说，培训潜力很大，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 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，就像 完成这一项目所需的所有必要设备和资源。

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.