Role of Focal Adhesion Kinase in Tumorigenesis

描述(由申请人提供)：本提案的总体目标是了解粘着斑激酶(FAK)信号在肿瘤发生过程中的作用。许多实验室的工作已经确定FAK是整合素和生长因子受体信号通路的组成部分。在许多晚期和转移性肿瘤中，FAK过度表达并高度酪氨酸磷酸化。然而，关于FAK如何在体内细胞转化和肿瘤进展过程中起作用，我们的了解非常有限。我们将检验整体假设，即FAK表达和活性的增加提供了选择性优势，通过提高锚定非依赖细胞的存活，通过调节金属蛋白酶的表达，并通过体内血管生成因子的释放来促进实体瘤的生长。特别是，我们将检验这一假设，即这些事件部分地通过RAC活性升高、JNK/SAP激酶信号转导以及基因表达事件的改变来调节。本提案的目的-1将利用FAK反义mRNA在体内外检测FAK在人腺癌细胞中表达上调的功能意义。AIM-2将通过显性-负性frnk表达来评价FAK酪氨酸磷酸化在体内外调节乳腺癌细胞生长/存活中的作用。AIM-3将通过比较转化的FAK缺失细胞和重组的FAK细胞，确定Src-FAK信号在体外促进细胞侵袭以及促进肿瘤生长和体内血管生成的分子联系。在所有这些研究中，我们将实施一种创新的策略，通过腺病毒介导的表位标记的FAK及其突变体的过表达来挽救FAK功能的丧失或缺失。这些研究将阐明FAK作为一种适配子蛋白与FAK作为信号转导蛋白的作用的功能差异。这些目标的实现将产生有关FAK信号作用的新信息，并将有助于开发控制肿瘤细胞生长和扩散的治疗策略。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to understand the role of focal adhesion kinase (FAK) signaling with respect to the processes of tumorigenesis. Work from a number of labs has identified FAK as a component of both integrin and growth factor receptor signaling pathways. In many advanced and metastatic tumors, FAK is overexpressed and highly tyrosine phosphorylated. However, our knowledge is very limited with regard to how FAK contributes to the processes of cell transformation and tumor progression in vivo. We will test the overall hypothesis that elevated FAK expression and activity provides a selective advantage promoting solid tumor growth through the enhancement of anchorage-independent cell survival, through the regulation of metalloproteinase expression, and through the release of angiogenic factors in vivo. In particular, we will test the hypothesis that these events are mediated in part through elevated Rac activity, JNK/SAP kinase signaling, and through the alteration of gene expression events. Aim-1 of this proposal will test the functional significance of elevated FAK expression in human adenocarcinoma cells in vitro and in vivo using FAK antisense mRNA. Aim-2 will evaluate the role of elevated FAK tyrosine phosphorylation in the regulation of mammary carcinoma cell growth/survival in vitro and in vivo using dominant-negative FRNK expression. Aim-3 will determine the molecular connections of Src-FAK signaling promoting cell invasion in vitro as well as enhanced tumor growth and angiogenesis in vivo through comparisons of Src-transformed FAK-null and FAK-reconstituted cells. In all of these studies, we will implement an innovative strategy of rescuing the loss or absence of FAK function through the adenoviral-mediated overexpression of epitope-tagged FAK and mutants of FAK. These studies will elucidate the functional differences of FAK as an adaptor protein compared to a role for FAK as signaling kinase. Achievement of these goals will yield new information on the role of FAK signaling and will aid in the development of therapeutic strategies to control the growth and spread of tumor cells.