Targeting Regulators of Apoptosis in AML

治疗急性髓性白血病（AML）的主要治疗挑战是开发 旨在克服对化疗的耐药性，特别是治疗复发患者的策略 成功地调节耐药白血病细胞存活的因素在很大程度上是未知的。这个项目 旨在确定耐药白血病细胞凋亡的障碍，并靶向 凋亡抗性我们分析了促凋亡基因和抗凋亡基因在新诊断的乳腺癌中的表达， 和复发的AML，并确定Bcl-2，Mcl-1和XIAP的关键作用。此外，我们还确定了 微环境对于AML的化学敏感性是重要的，并鉴定了趋化因子受体CXCR 4 作为一个关键的调解人。最后，我们分析了AML中的PI 3 K/AKT/mTOR和Raf/Mek/Erk信号传导， 确定了其功能和预后的重要性。这些发现导致了小说的发展 AML的治疗概念。AML生存的关键分子成为治疗靶点， 因此开始了审判（项目4、5）。这些临床试验成为验证 假设发展。首先，我们将检验内源性凋亡途径的激活 使AML和AML干细胞（LSC）对化疗敏感。小分子和遗传方法将 用于靶向Bcl-2和Mcl-1，但整个Bcl-2家族将在大量AML和LSC中进行分析， 与利用反相蛋白质阵列（RPPA）的响应相关。激酶对Bcl-2和 将测定Mcl-1磷酸化状态和药物敏感性。第二，我们将探讨p53激活 作为AML的治疗策略，单独和在Bcl-2抑制的情况下。我们已经 证明了单独的MDM 2抑制诱导具有wtp 53的AML中的p53信号传导和细胞凋亡。我们将 现在研究MDMX、p53乙酰化和磷酸化的作用以及p53和Bcl-2的相互作用 为了更好地理解观察到的MDM-2抑制剂的活性及其与Bcl-2抑制剂的协同作用。 第三，建立骨髓微环境的体外模型，分析信号通路 研究CXCR 4、VLA-4和ILK抑制剂在克服白血病和间质中诱导的免疫应答中的作用。 微环境介导的耐药性如果成功的话，这些研究将为 针对白血病细胞及其微环境的改良AML疗法。

The main therapeutic challenge in the treatment of acute myeloid leukemias (AML) is the development of strategies aimed at overcoming resistance to chemotherapy and in particular to treat relapsed patients successfully. The factors regulating the survival of resistant leukemic cells are largely unknown . This project is designed to identify roadblocks to apoptosis in resistant leukemia cells and target mechanisms of apoptotic resistance. We have analyzed the expression of pro- and anti-apoptotic genes in newly diagnosed and relapsed AML and determined critical roles for Bcl-2, Mcl-1 and XIAP. Furthermore, we identified the microenvironment as important for chemosensitivity of AML and identified the chemokine receptor CXCR4 as a critical mediator. Finally,we analyzed PI3K/AKT/mTOR and Raf/Mek/Erk signaling in AML and established their functional and prognostic importance. These findings have led to the development of novel therapeutic concepts for AML. Molecules critical for AML survival became therapeutic targets and clinical trials have been initiated as a result (Proj.4,5). These clinical trials become the ultimate test to validate the hypotheses developed. First, we will test the hypothesis that activation of the intrinsic apoptosis pathway sensitizes AML and AML stem cells (LSC) to chemotherapy. Small molecules and genetic approaches will be used to target Bcl-2 and Mcl-1 , but the entire Bcl-2 family will be analyzed in bulk AML and LSC and correlated with response utilizing reverse-phase protein arrays (RPPA). The effects of kinases on Bcl-2 and Mcl-1 phosphorylation status and drug sensitivity will be determined. Second, we will explore p53 activation as a therapeutic strategy for AML, alone and in the context of Bcl-2 inhibition. We have already demonstrated that MDM2-inhibition alone induces p53 signaling and apoptosis in AML with wtp53. We will now investigate the role lof MDMX, of p53 acetylation and phosphorylation and interactions of p53 and Bcl-2 to better understand the observed activity of MDM-2 inhibitors and their synergism with Bcl-2 inhibitors. Third, we will develop in vitro models of bone marrow microenvironment, analyze signaling pathways induced in leukemias and stroma, and investigate effects of CXCR4, VLA-4 and ILK inhibitors in overcoming microenvironment-mediated drug resistance. If successful, these studies will provide rationale for greatly improved therapies for AML that target both, the leukemic cells and their microenvironment.