NEK2 Over-expression Causes Drug Resistance in Myeloma

描述(由申请人提供)： 这项工作的长期目标是确定NEK2在促进癌症进展中的功能作用，并利用这一知识开发新的治疗方法。多发性骨髓瘤患者的生存期从几个月到10年不等。我们以前已经证明，在包括骨髓瘤在内的多种癌症中，NEK2-表达增加；较高水平的NEK2-表达诱导细胞快速生长和对多种化疗药物的耐药性。这个项目建立在我们的发现基础上，当调节细胞周期的特定基因(NEK2)过度表达时，患者会经历一种临床侵袭性的形式，并迅速死亡骨髓瘤和其他癌症。我们有几个惊人的发现，支持这样一种假设，即NEK2的过度表达扰乱了肿瘤细胞的正常增殖周期，导致骨髓瘤患者的生存不良。我们检验这一假说的目标将通过使用体外和体内模型执行三个特定目标来实现。目的：探讨NEK2在骨髓瘤发生发展中的作用。我们建议评估NEK2高表达的骨髓瘤细胞在不同阶段的大量骨髓瘤患者中是否具有耐药特征；我们还将检测NEK2高表达或低表达的原代骨髓瘤细胞的体外和体内的生长和耐药性；我们将NEK2导入内源性NEK2低表达的正常成纤维细胞和小鼠骨髓瘤细胞系，然后分析这种变化对细胞转化、细胞生长和化疗药物反应的影响。目的：探讨NEK2介导的信号通路在癌细胞增殖和存活中的作用。为了实现这一目标，我们将确定在多发性骨髓瘤中，NEK2介导的细胞生长和耐药是否需要一些与细胞生长相关的信号通路。我们将研究直接与NEK2蛋白相互作用的关键底物。此外，还将对缓解和复发的骨髓瘤样本进行基因表达谱(GEP)分析，这些样本的基线GEP也是GEP，以确定不同骨髓瘤阶段受NEK2调控的基因。目的3：开发以NEK2或其信号通路为靶点的新型治疗方法。通过对激酶抑制剂文库的筛选，我们已经鉴定出两个小分子，它们可以特异性地抑制NEK2激酶的活性，并在体外诱导癌细胞显著死亡。我们将利用这些分子作为工具来探索它们在体内杀死骨髓瘤细胞的有效性。针对这些信号通路的抑制剂将单独使用或与目前使用的化疗药物联合使用，以评估它们在体外和体内的抗骨髓瘤活性。

DESCRIPTION (provided by applicant): The long-term objective of this work is to determine the functional role of NEK2 in promoting cancer progression and to use this knowledge to develop novel therapies. The variability in survival of multiple myeloma patients ranges from only a few months to >10 years. We have previously shown that NEK2- expression is increased in multiple cancers including myeloma; higher levels of NEK2-expression induce cell rapid growth and resistance to multiple chemotherapeutics. This project builds upon our finding that when a specific gene (NEK2) that regulates the cell cycle is overexpressed, patients experience a clinically aggressive form and rapid death of myeloma and other cancers. We have made several striking discoveries supporting the hypothesis that NEK2 over-expression disrupts the normal cycle of tumor cell proliferation, resulting in poor survival for myeloma patients. Our goal to test the hypothesis will be accomplished by execution of three specific aims using both in vitro and in vivo models. Aim1: To examine the role of NEK2 in the development and progression of myeloma. We propose to evaluate whether myeloma cells with high-NEK2 expression are characterized with drug resistance in a large cohort of patients with myeloma at different stages; we will also test the growth and drug-resistance of primary myeloma cells with NEK2 high- or NEK2 low-expression in vitro and in vivo; we will introduce NEK2 into normal fibroblast cells and murine cancer-derived myeloma cell line that have low endogenous NEK2 expression, we will then analyze the effects of this alteration on cell transformation, cellular growth, and response to chemotherapeutic agents. Aim 2: to determine NEK2-mediated signaling pathways in cancer cell proliferation and survival. To achieve this goal, we will determine whether some cell growth related signaling pathways are required for NEK2-mediated cell growth and drug resistance in multiple myeloma. We will examine key substrates that directly interact with the NEK2 protein. Furthermore, gene expression profiling (GEP) will be performed on myeloma samples in remission and at relapse who also have GEP at baseline to identify genes that are regulated by NEK2 at different myeloma stages. Aim 3: to develop novel treatments based on targeting NEK2 or its signaling pathways. Through the screen of kinase inhibitor libraries, we have identified two small molecules that can specifically inhibit NEK2 kinase activity, and induce dramatic cancer cell death in vitro. We will use these molecules as a tool to explore their efficacy in killing myeloma cells in vivo. Inhibitors targeting these signaling pathways will be used alone or in combination with the current used chemotherapeutic drugs to evaluate their antimyeloma activities in vitro and in vivo.