Abl kinases in growth factor signaling, motility and invasion

描述（由申请人提供）：生长因子调节细胞增殖、迁移和存活。这些过程的精确调控是至关重要的，因为不受调控的生长因子信号会增加细胞迁移并驱动肿瘤侵袭和转移，这是癌症相关死亡的主要原因。虽然Abl非受体酪氨酸激酶启动白血病的发展，但其在实体瘤的发展或进展中的作用尚未被研究。先前，我们发现Abl激酶通过Src家族激酶和PLC-yl在生长因子受体下游被激活，并影响成纤维细胞中生长因子介导的细胞骨架重组和迁移。在实体肿瘤（如乳腺癌）中，生长因子受体、Src激酶和PLC-yl的失调驱动肿瘤的侵袭和转移。我们的研究表明，在高侵袭性乳腺癌细胞系中，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，本提案的总体目标是表征导致Abl激酶在乳腺癌中激活的条件，并定义由Abl激酶控制的促进侵袭的信号级联。我们假设Abl家族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。本文描述了三个具体目的来评估这一假设：1)确定乳腺癌中激活Abl激酶的条件；2)明确Abl激酶促进乳腺癌细胞侵袭的生物学和分子机制；3)在体内确定Abl激酶的激活是否促进乳腺癌转移。为了实现我们的目标，我们将结合生化、分子、细胞和整个动物的方法，使用：1)原发乳腺组织，乳腺癌细胞系；RNAi和抑制剂鉴定Abl活化的机制和条件；2)通过RNAi、趋化性、侵袭和酶谱分析来确定Abl激酶促进侵袭的机制；3)体内转移研究，以评估激活Abl激酶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制见解，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.