P53 Activation as Novel Therapeutic Strategy for Acute Myelogenous Leukemia

该项目的主要目标是改善急性髓系白血病患者的治疗结果和治愈率。 通过开发新的、非遗传毒性的治疗策略，最大限度地诱导白血病， 细胞凋亡TP53是细胞凋亡的主要调节因子，其经常通过MDM2的过表达而失活。 通过用非遗传毒性小分子抑制剂抑制MDM2-p53相互作用恢复p53活性 （Nutlin-3a，RG7112，MI-63）显著增加细胞p53水平并诱导细胞凋亡。在过去的融资 在此期间，我们已经产生了临床前和临床证据来支持这一概念。虽然AML中的许多p53 p53定位于细胞质中，只有细胞核中的p53可以作为转录因子发挥作用。Exportini（CRM 1）是主要的 p53核转运蛋白。初步数据表明，CRM1过表达与患者预后不良有关。 急性髓细胞白血病SINE（selective inhibitors of nuclear export）是一种新型的、强效的、不可逆的、选择性的小分子化合物 CRM1的抑制剂[5，6]。我们的总体假设是，CRMI抑制和非CRMI抑制导致的p53核滞留， 通过抑制MDM2的基因毒性激活p53将诱导/增强AML中的细胞凋亡。另外我们 假设p53是微环境功能重要决定因素。在目标1中，我们将测试 AML中通过CRMI抑制阻断p53核输出增强由CRMI诱导凋亡的假说 M0M2抑制。我们报道AML细胞主要在细胞质中表达p53，并假设 CRMI抑制导致p53的核积累和活性，从而增强p53介导的转录。 依赖性凋亡SINE在正常人细胞中具有最小的毒性，包括体外造血细胞， in vivo.我们的初步数据显示，SINE以p53依赖的方式诱导AML中的细胞死亡。我们将 研究通过CRMI抑制的p53核保留是否与通过MDM2抑制的p53积累协同， 诱导AML细胞凋亡。在目标2中，我们将研究MDM2和CRMI抑制对p53激活的作用。 在骨髓微环境中。骨髓基质细胞保护AML细胞免受各种抗白血病药物的影响 药物，但MDM2抑制剂Nutlin-3a或SINE KPT-185即使在药物存在下也能杀死AML细胞。

The primary goal of this project is to improve treatment outcomes and cure rates of patients with acute myelogenous leukemia (AML) by developing novel, non-genotoxic therapeutic strategies that maximize the induction of leukemia cell apoptosis. TP53 is the master regulator of apoptosis that is frequently inactivated by overexpression of MDM2. Restoration of p53 activity by inhibition of MDM2-p53 interaction with non-genotoxic small molecule inhibitors (Nutlin-3a, RG7112, MI-63) dramatically increases cellular p53 levels and induces apoptosis. During the past funding period, we have generated pre-clinical and clinical evidence to support this concept. While much p53 in AML is localized in the cytoplasm, only nuclear p53 can function as transcription factor. Exportini (CRM1) is the major nuclear transporter of p53. Preliminary data suggest that CRM1 overexpression is associated with poor prognosis in AML. SINEs (selective inhibitors of nuclear export) are new, potent, irreversible and selective small molecule inhibitors of CRM1 [5, 6]. Our overall hypothesis is that nuclear retention of p53 by CRMI inhibition and non- genotoxic activation of p53 by inhibition of MDM2 will induce/enhance apoptosis in AML. in addition, we hypothesize that p53 is an important determinant of microenvironmental function. In Aim 1 we will test the hypothesis that blockade of p53 nuclear export by CRMI inhibition in AML enhances apoptosis induced by M0M2 inhibition. We reported that AML cells express p53 predominantly in the cytoplasm and hypothesize that CRMI inhibition results in nuclear accumulation and activity of p53, thereby enhancing p53-mediated transcription- dependent apoptosis. SINEs have minimal toxicities in normal human cells, including hematopoietic cells in vitro and in vivo. Our preliminary data show that SINEs induce cell death in AML in a p53-dependent manner. We will investigate if nuclear retention of p53 by CRMI inhibition synergizes with accumulation of p53 by MDM2 inhibition to induce apoptosis in AML. In Aim 2 we will investigate the role of p53 activation by MDM2 and CRMI inhibition in the bone marrow microenvironment. Bone marrow stromal cells protect AML cells from various anti-leukemic agents, but the MDM2 inhibitor Nutlin-3a or SINE KPT-185 kill AML cells even in the presence of