Dual Kinase and LSD1 Inhibition in Acute Myeloid Leukemia

项目摘要/摘要 激酶抑制剂治疗对急性髓系白血病患者的临床治疗影响很小 白血病(AML)。我们已经证明，抑制表观遗传调节因子赖氨酸特异的脱甲基酶1(LSD1) 增强急性髓系白血病的激酶抑制疗效，包括针对Flt3、cKit和JAK2的药物。这种情况会发生 通过抑制MYC超级增强子(MYC-SE)，导致MYC基因表达和 因此，促进增殖的基因表达程序的表达减少。然而，我们缺乏一个 对于激酶加LSD1抑制是如何产生这种效应的，或者药物是否 组合具有独立于MYC-SE的重要影响。我们的长期目标是建立 激酶加LSD1抑制治疗急性髓系白血病的疗效，将这一概念转化为新的有效治疗方法 急性髓系白血病患者。这项提案的总体目标是：1)确定药物反应的机制基础 Flt3+LSD1抑制Flt3基因突变的AML和2)评估MEK和LSD1双重抑制的可能性 在NRAS-突变型AML中。我们的中心假设是MYC靶基因的抑制是必不可少的 激酶加LSD1抑制介导的细胞死亡机制。在目标1中，我们将调查三种可能 Flt3加LSD1抑制MYC靶基因的机制：1)通过失活 MYC-SE导致MYC基因表达降低，导致MYC靶基因表达丢失，2)通过 抑制依赖LSD1的MYC靶基因的激活；3)通过抑制信号通路 下游激活的Flt3，导致MYC失去与靶基因启动子的结合。我们还将 在参加FRIDA试验的AML患者中进行相关研究，调查这些机制，接受 Flt3加LSD1抑制剂治疗。在目标2中，我们将评估MEK plus的疗效和作用机制 用染色质和信号通路的综合评价对NRAS突变型AML进行LSD1抑制剂治疗 动力学。我们还将使用多种NRAS突变型AML小鼠模型，包括患者来源的 异种移植模型。在这些研究完成后，我们的预期结果是：1)确定了FLT3是如何 加用LSD1抑制可导致Flt3突变型AML的细胞死亡；2)建立双重MEK的临床前疗效 在NRAS突变型AML中加LSD1抑制。这些研究将提供关键的临床前理论基础，以扩大 激动剂加LSD1抑制剂的适应症适用于更大比例的AML患者。

PROJECT SUMMARY/ABSTRACT Kinase inhibitor therapy has made a minimal impact on the clinical treatment of patients with Acute Myeloid Leukemia (AML). We have shown that inhibition of the epigenetic regulator lysine-specific demethylase 1 (LSD1) augments the efficacy of kinase inhibition in AML, including drugs targeting FLT3, cKIT and JAK2. This occurs via the repression of the MYC super enhancer (MYC-SE), leading to a loss of MYC gene expression and consequently decreased expression of a pro-proliferative gene expression program. However, we lack a complete mechanistic understating of how kinase plus LSD1 inhibition produces this effect, or whether the drug combination has important effects that are independent from the MYC-SE. Our long-term objective is to establish the efficacy of kinase plus LSD1 inhibition in AML, translating this concept into new effective treatment for patients with AML. The overall objective of this proposal is to: 1) define the mechanistic basis for drug responses to FLT3 plus LSD1 inhibition in FLT3-mutant AML and 2) evaluate the potential of dual MEK and LSD1 inhibition in NRAS-mutant AML. Our central hypothesis is that the suppression of MYC-target genes is an essential mechanism of kinase plus LSD1 inhibition-mediated cell death. In Aim 1, we will investigate three possible mechanisms for FLT3 plus LSD1 inhibition-induced suppression of MYC target genes: 1) Via inactivation of the MYC-SE leading to decreased MYC gene expression resulting in a loss of MYC-target gene expression, 2) Via inhibition of LSD1-dependent activation of MYC-target genes and 3) through inhibition of signaling pathways down-stream of activated FLT3, resulting in a loss of MYC binding to the promoters of target genes. We will also perform correlative studies investigating these mechanisms in AML patients enrolled in the FRIDA trial, receiving FLT3 plus LSD1-inhbitor therapy. In Aim 2, we will evaluate the efficacy and mechanism of action of MEK plus LSD1 inhibitor therapy in NRAS-mutant AML, using an integrated evaluation of chromatin and signaling pathway dynamics. We will also employ multiple mouse models of NRAS-mutant AML including a patient-derived xenograft model. At the completion of these studies, our expected outcomes are to 1) have identified how FLT3 plus LSD1 inhibition drives cell death in FLT3-mutant AML and 2) establish the preclinical efficacy of dual MEK plus LSD1 inhibition in NRAS-mutant AML. These studies will provide key pre-clinical rationale for expanding the indications for kinase plus LSD1 inhibitor to a larger proportion of patients with AML.