Defining a role for Hunk in oncogenic signaling

描述(由申请人提供)：这项建议的目标是了解HUNK在细胞内的作用机制，并确定HUNK蛋白在肿瘤发生中的作用。这项提案的第一个目标将解决大块头在神经驱动的乳腺肿瘤发生中的参与。这些实验对于确定Neu作用于肿瘤形成和维持的机制很重要。由于在约30%的人类乳腺癌中观察到Neu变性，这些研究将为开发更有效的治疗方法提供更多的洞察力。这一目标将使用体内遗传方法来实现，该方法采用小鼠模型，该模型包含一个可诱导的系统来驱动Neu肿瘤的发生。然后，这些动物将与缺乏体块的小鼠杂交，产生神经诱导的体型野生型和缺乏体型的动物。这些动物将被用于长期的慢性诱导研究，以确定大块头在肿瘤潜伏期和多发性中的作用。此外，还将进行短期诱导，以表征BUNK对Neu驱动的细胞生长和增殖的影响。最后，这个系统将被用来解决块蛋白在神经元特异性信号转导中的作用。该提案的第二个目标将解决BUNK在PI3K-Akt信号中的作用。由于BUNK是一种最近发现的蛋白激酶，人们对其作为信号分子的作用知之甚少。然而，我们已经获得了与PI3K-Akt信号有关的初步证据。为了解决第二个目标，我们将利用细胞生物学和生化技术来建立乳腺中BUNK和PI3K-Akt信号之间的关系。具体地说，我们将确定HUNK和Akt之间是否存在物理相互作用，HUNK是否是Akt的底物，以及Akt通过PI3K激活是否影响BUNK蛋白水平和/或活性。还将进行实验，以确定BUNK活性和/或水平是否影响Akt通过PI3K的信号传递能力。最后，这些实验将包括体内遗传学研究，以确定BUNK是否影响Akt依赖的肿瘤发生。Akt通路在许多人类癌症中发生突变，与Neu相似，乳腺癌中Akt活性经常增加。因此，本提案中概述的研究对于了解乳腺癌的分子基础以及如何更有效地治疗乳腺癌非常重要。据估计，2006年乳腺癌将成为女性癌症相关死亡的主要原因。几种蛋白激酶抑制剂对人类癌症的治疗非常有效。因此，确定新的治疗靶点是改善人类健康的重要因素。

DESCRIPTION (provided by applicant): The goal of this proposal is to understand the mechanism by which Hunk acts intracellularly and determine the role of Hunk protein in tumorigenesis. The first aim of this proposal will address the participation of Hunk in Neu-driven mammary tumorigenesis. These experiments are important to determine the mechanisms by which Neu acts on tumor formation and maintenance. As Neu abberrations are observed in ~30% of human breast cancers, these studies will provide additional insight into the development of more effective treatments. This aim will be addressed using in vivo genetic approaches that employ a mouse model that encorporates an inducible system to drive Neu oncogenesis. These animals will then be crossed with Hunk deficient mice to generate Neu-inducible Hunk wildtype and deficient animals. These animals will be used for long-term chronic induction studies to identify a role for Hunk in tumor latency and multiplicity. In addition, short-term inductions will be performed to characterize the affect of Hunk on Neu-driven cell growth and proliferation. Finally this system will be used to address the role of Hunk in Neu-specific signaling. The second aim of this proposal will address the role of Hunk in PI3K-Akt signaling. As Hunk is a recently discovered protein kinase, little is known about its role as a signaling molecule. However, we have obtained preliminary evidence implicating Hunk in PI3K-Akt signaling. To address the second aim we will employ cell biology and biochemical techniques to establish the relationship between Hunk and PI3K-Akt signaling in the mammary gland. Specifically, we will determine whether a physical interaction exists between Hunk and Akt, whether Hunk is a substrate of Akt, and whether the activation of Akt through PI3K impinges on Hunk protein levels and/or activity. Experiments will also be performed to address the whether Hunk activity and/or levels affect the signaling capacity of Akt through PI3K. Finally, these experiments will include in vivo genetic studies to determine whether Hunk influences Akt-dependent tumorigenesis. The Akt pathway is mutated in many human cancers and, similar to Neu, there is frequently an increase in Akt activity in breast cancers. Consequently, the studies outlined in this proposal are important for understanding the molecular basis of breast cancer and how it can be more effectively treated. It is estimated that breast cancer will be the leading cause of cancer-related death in women in 2006. Several protein kinase inhibitors have been extremely effective for the treatment of human cancer. As such, characterization of novel therapeutic targets is an important element for improving human health.