REGULATION OF AURORA-A KINASE ACTIVITIES BY AURORA-A INTERACTING PROTEINS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 癌症研究人员面临的一个主要挑战是开发显著提高治愈率的技术。只有当我们更充分地了解癌症的病理生理学，以便发现新的抗癌药物，并更好地整合药物基因组学时，才能实现这一点。Aurora-A在细胞周期和有丝分裂过程中调节多个过程，包括中心体成熟、有丝分裂进入、核膜破裂、两极纺锤体的形成和取向、胞质分裂和细胞不对称分裂的极性。因此，Aurora-A在过多的癌症中被发现扩增也就不足为奇了，特别是白血病和上皮性肿瘤，即乳腺癌、结肠癌、膀胱癌、卵巢癌和胰腺癌。Aurora-A可能促进肿瘤的发生、发展和转移，其功能障碍可能会以多种不同的方式导致细胞转化和癌症。通过与不同的Aurora-A相互作用蛋白(AurAIP)相互作用，Aurora-A可以组装成不同的信号模块，其错误调节可能会将细胞转化为不同类型的癌症，从而对Aurora-A抑制剂产生不同的反应。因此，迫切需要了解这些通路是如何被激活的以及它们被激活的结果，以便了解它们在肿瘤形成中的作用并制定治疗策略。我们实验室的长期目标是开发一种利用Aurora A激酶(Aurora-A)途径进行癌症治疗的有效诊断和治疗方法。我们建议利用我们对Aurora-A是如何被Aurora-A相互作用蛋白(AurAIP)激活的理解来开发翻译应用程序，这将增强群体靶向治疗的潜力。 我们的实验室已经确定了几个致癌AurAIP之一的TPX2是第一个被确认为Aurora-A的激活剂。我们已经确定HURP是另一个AurAIP，它能激活非洲爪哇卵提取液中的Aurora-A。我们将利用我们实验室开发的新的分析方法来了解Aurora-A是如何在有丝分裂的各个步骤中被这些结构无关的AurAIP调控的。了解每个Aurora-A激活途径如何与肿瘤发生联系，将有助于快速诊断，并确保Aurora-A途径的适当人群靶向用于抗癌治疗。 A.1.研究AurAIP与Aurora-A的相互作用是如何调节的 我们已发表的研究描述了一个AurAIP，TPX2，如何在时空上与Aurora-A相互作用。简单地说，活性TPX2与Aurora-A相互作用，并将Aurora-A靶向纺锤体。Importin与TPX2的结合阻止了TPX2与Aurora-A的相互作用。RAN是纺锤体组装的空间调节剂，可将TPX2从Importin？/？的抑制结合中释放出来。在这个目标中，我们将描述其他AurAIP与Aurora-A的相互作用是如何在细胞周期进程中调节的。 A.2.检查Aurora-A与其底物的结合是否受AurAIPs的调节 为了发挥分子支架的作用，AurAIPs应该能够通过局部浓缩蛋白质和将Aurora-A定位在靠近其底物的位置来提高信号传递的效率。我们将研究AurAIPs是否也通过选择性地将特定底物(S)带到Aurora-A来调节Aurora-A的路径特异性。 A.3.研究AurAIP如何调节Aurora-A功能 虽然人们对AurAIP的功能进行了大量的研究，但很少有研究针对了解这些AurAIP的作用是如何相互耦合的，以及这种耦合是否在Aurora-A功能的调节中起重要作用。解决这一问题的研究一直受到缺乏分析的阻碍，这使得人们无法解决交叉监管的复杂问题。我们计划使用一些体外和体内实验来研究四个AurAIP如何协调调节Aurora-A功能。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A major challenge facing cancer researchers is the development of technologies that significantly increase cure rates. This can only be achieved when we more fully understand cancer pathophysiology so that new anticancer agents can be discovered and better integration of pharmacogenomics can be developed. Aurora-A regulates multiple processes during the cell cycle and mitosis, including centrosome maturation, mitosis entry, nuclear envelope breakdown, bi-polar spindle formation and orientation, cytokinesis and cell polarity for asymmetric cell division. Thus, it is not surprising that Aurora-A is found to be amplified in a plethora of cancers particularly leukemia and those of epithelial origin, namely, breast, colon, bladder, ovarian, and pancreatic. Aurora-A may promote tumor initiation, progression and metastasis, and its malfunction may lead to cell transformation and cancer in a number of different ways. By interacting with distinct Aurora-A interacting proteins (AurAIPs), Aurora-A could assemble into different signaling modules, and its misregulation could transform cells into different cancer types that would differentially respond to Aurora-A inhibitors. Thus, there is an urgent need to understand how these pathways are activated and the result of their activation in order to understand their role in neoplasia and develop strategies for treatment. The long-term goal of our lab is to develop an effective diagnosis and therapeutic approach for cancer treatment utilizing the Aurora A kinase (Aurora-A) pathways. We proposed to use our understanding of how Aurora-A is activated by Aurora-A interacting proteins (AurAIPs) to develop translational applications, which will enhance the potential for population-targeted therapy. Our lab has characterized one of the several oncogenic AurAIPs, TPX2 as the first activator identified for Aurora-A. We have identified HURP as another AurAIP that activates Aurora-A in Xenopus egg extract. We will utilize novel assays developed by our lab to understand how Aurora-A is regulated by these structurally-unrelated AurAIPs in the various steps of mitosis. Understanding how each Aurora-A activation pathway links to tumorigenesis will facilitate rapid diagnosis and ensure appropriate population targeting of the Aurora-A pathway for anti-cancer therapy. A.1. Examine how AurAIPs interaction with Aurora-A is regulated Our published studies have characterized how one AurAIP, TPX2, spatiotemporally interacts with Aurora-A. Briefly, active TPX2 interacts with Aurora-A and targets Aurora-A to the spindle. Binding of Importin ¿/¿ to TPX2 prevents TPX2 from interacting with Aurora-A. Ran is a spatial regulator of spindle assembly that can release TPX2 from the inhibitory binding of Importin ¿/¿. In this aim, we will characterize how the interaction of other AurAIPs with Aurora-A is regulated in cell cycle progression. A.2. Examine whether the association of Aurora-A with its substrates is regulated by AurAIPs To function as molecular scaffolds, AurAIPs should be able to increase the efficiency of signaling by locally concentrating proteins and positioning Aurora-A in close proximity to its substrates. We will investigate whether AurAIPs also regulate pathway-specificity of Aurora-A by selectively bringing specific substrate(s) to Aurora-A. A.3. Examine how AurAIPs regulate Aurora-A function Although much effort has been devoted to studying the functions of AurAIPs individually, very few studies have been directed at understanding how the actions of these AurAIPs are coupled with one another and whether this coupling is important in the regulation of Aurora-A function. Studies addressing this question have been hampered by a lack of assays allowing one to address the complex issue of cross regulation. We plan to use a number of in vitro and in vivo assays to study how four AurAIPs might coordinately regulate Aurora-A function.