Abl Kinases in growth factor signaling, motility, and invasion

描述(申请人提供)：生长因子调节细胞的增殖、迁移和存活。这些过程的精确调控至关重要，因为解除调控的生长因子信号增加了细胞迁移，并推动了肿瘤的侵袭和转移，这是癌症相关死亡的主要原因。尽管Abl非受体酪氨酸激酶启动了白血病的发生，但它们在实体瘤的发生和发展中的作用尚未被研究。在此之前，我们已经证明Abl激酶通过Src家族和PLC-1激活生长因子受体下游，并影响生长因子介导的成纤维细胞的细胞骨架重组和迁移。在实体肿瘤中，如乳腺癌中，生长因子受体、Src激酶和PLC-1的失控会导致肿瘤的侵袭和转移。我们的研究表明，在高度侵袭性的乳腺癌细胞系中，Abl激酶在激活的生长因子受体和Src激酶下游被显著激活，并促进乳腺癌的侵袭。基于这些发现，这项建议的总体目标是表征导致乳腺癌Abl激酶激活的条件，并确定由Abl激酶控制的促进侵袭的信号级联反应。我们假设，Abl家族的激酶翻译并引导生长因子受体和Src激酶介导的信号影响乳腺癌的侵袭和转移。评估这一假说的三个具体目标是：1)确定激活乳腺癌中Abl激酶的条件；2)确定Abl激酶促进乳腺癌细胞侵袭的生物学和分子机制；以及3)确定Abl激酶的激活是否促进乳腺癌的体内转移。为了实现我们的目标，我们将结合生化、分子、细胞和整个动物方法，使用：1)原代乳腺组织、乳腺癌细胞株；RNAi和抑制剂，以确定Abl激活的机制和条件；2)RNAi、趋化、侵袭和酶谱分析，以确定Abl激酶促进侵袭的机制；以及3)体内转移研究，以评估Abl激酶的激活是否促进免疫受损小鼠的转移。这些数据可能为ABL激酶的异常调节如何促进乳腺癌进展提供机械性的见解，这可能有助于发现预防乳腺癌转移和降低死亡率的新药物组合。

DESCRIPTION (provided by applicant): Growth factors modulate cell proliferation, migration, and survival. Precise regulation of these processes is critical as deregulated growth factor signaling increases cellular migration and drives tumor invasion and metastasis, the major cause of cancer-related deaths. Although Abl nonreceptor tyrosine kinases initiate leukemia development, their role in the development or progression of solid tumors has not been studied. Previously, we showed that Abl kinases are activated downstream of growth factor receptors via Src family kinases and PLC-yl, and influence growth factor-mediated cytoskeletal reorganization and migration in fibroblasts. Deregulation of growth factor receptors, Src kinases and PLC-yl in solid tumors, such as breast cancer, drives tumor invasion and metastasis. Our studies demonstrate that the Abl kinases are dramatically activated downstream of activated growth factor receptors and Src kinases in highly aggressive breast cancer cell lines, and promote breast cancer invasion. Based on these findings, the overall objective of this proposal is to characterize the conditions leading to Abl kinase activation in breast cancer, and to define invasion-promoting signaling cascades controlled by the Abl kinases. We hypothesize that Abl family kinases translate and direct growth factor receptor and Src kinase-mediated signals to influence breast cancer invasion and metastasis. Three Specific Aims are described to evaluate this hypothesis: 1) Determine the conditions that activate the Abl kinases in breast cancer; 2) Identify biological and molecular mechanisms by which Abl kinases promote breast cancer cell invasion; and 3) Determine whether activation of the Abl kinases promotes breast cancer metastasis, in vivo. To achieve our goal, we will combine biochemical, molecular, cellular, and whole animal approaches using: 1) primary breast tissue, breast cancer cell lines; RNAi, and inhibitors to identify mechanisms and conditions of Abl activation; 2) RNAi, chemotaxis, invasion, and zymography assays to identify mechanisms by which Abl kinases promote invasion; and 3) in vivo metastasis studies to assess whether activation of the Abl kinases promotes metastasis in immune- compromised mice. These data are likely to provide mechanistic insight into how abnormal regulation of the Abl kinases contributes to breast cancer progression, which may aid in the discovery of new drug combinations for preventing breast cancer metastasis and decreasing mortality.