Targeting invadopodia-related mechanisms of cancer cell invasion and metastasis

转移导致>90%的乳腺癌相关死亡。肿瘤细胞结构已经被 假设转移所必需的是侵袭伪足，富含结构蛋白的突起（例如， Tks 5）、粘附蛋白（例如整联蛋白β1）和蛋白酶（例如MT 1-MMP），已知这些蛋白酶降解细胞内的细胞因子。 细胞外基质（ECM）蛋白。 一种新的，实时成像方法，允许调查的体内转移作用， invadopodia发现组装invadopodia的细胞以“慢”速度移动，并在 血管周围的壁龛在血管周围小生境之外，“快速”运动细胞，其不组装侵入伪足， 观察了该方法还表明，侵入伪足是必需的在体内的血管内渗。 初步的工作已经开始，以确定哪些方面的慢表型允许侵入伪足 组装件.使用新型数学模型、体外显微镜和新型计算图像分析 这表明，虽然快细胞不断迁移，慢细胞是在两个 振荡状态：i.侵入伪足状态，其中细胞是固着的，同时其降解周围的ECM; ii. 运动状态，类似于快速细胞。振荡动力学似乎取决于 ECM及其受体整合素β1。重要的是，入侵状态，而不是运动状态，仅限于 细胞周期的G1期。从G1期阻滞释放放大了侵袭足，这意味着G1期阻滞 治疗可促进转移。这个项目将确定独特的机制入侵足 与只增殖或增殖的细胞相比，这种状态具有靶向入侵状态的想法。 总的假设：侵袭伪足状态，这是转移所必需的，需要 在细胞运动和细胞周期进程中暂停。的启动和终止 入侵伪足状态由细胞外基质、入侵伪足成分之间的相互作用控制 整合素β1和Tks 5，以及细胞周期蛋白依赖性激酶抑制剂p27（在G1期表达）。 目标1.确定细胞周期在调节侵袭足状态中的作用。使用实时 成像细胞周期和侵入伪足标记在体外和体内，这个目的测试的假设，细胞周期蛋白， 依赖性激酶和相应的抑制剂调节内陷足状态，但不调节运动。 目标2.确定ECM-癌细胞相互作用在调节细胞间振荡中的作用 Invadopodia和Locomotion状态。这一目标将提供一种基于体内修饰的策略， 整合素β1活性对如何将侵袭伪足状态“关闭”以防止转移的影响。 意义侵袭伪足被认为是转移预防的新候选靶点。使用 侵袭性伪足患者的细胞周期抑制剂可能加速转移性播散。很长的- 长期目标是利用侵袭伪足预测和预防转移。

Metastasis causes >90% of breast cancer-related deaths. Tumor cell structures that have been hypothesized as necessary for metastasis are invadopodia, protrusions rich in structural proteins (e.g. Tks5), adhesion proteins (e.g. integrin β1) and proteases (e.g. MT1-MMP), known to degrade the extracellular matrix (ECM) proteins. A novel, real-time imaging methodology that allows investigation of the in vivo metastatic role of invadopodia found that cells which assemble invadopodia move at “Slow” speeds and are seen in perivascular niches. Outside of perivascular niches, “Fast” motile cells, which do not assemble invadopodia were observed. This method also showed that invadopodia are essential for intravasation in vivo. Preliminary work has begun to determine which aspects of the Slow phenotype allow invadopodia assembly. Use of novel mathematical models, in vitro microscopy and novel computational image analysis demonstrates that whereas the Fast cells continuously locomote, the Slow cells are in either of two oscillating states: i. Invadopodia state, in which a cell is sessile while it degrades surrounding ECM; ii. Locomotion state, similar to a Fast cell. The oscillation dynamics appear to depend on interactions between the ECM and its receptor integrin β1. Importantly, the Invadopodia, but not Locomotion state, is limited to G1 phase of the cell cycle. Release from G1-arrest amplifies invadopodia, implying that G1-arresting therapies may promote metastasis. This project will identify the mechanisms unique to the Invadopodia state compared to cells that only proliferate or locomote, with the idea of targeting the Invadopodia state. Overall Hypothesis: the Invadopodia state, which is essential for metastasis, requires a pause in both cell locomotion and cell cycle progression. The initiation and termination of the Invadopodia state are controlled by the interaction between the ECM, invadopodia components integrin β1 and Tks5, as well as the cyclin-dependent kinase inhibitor p27 (expressed during G1). Aim 1. Determine the role of the cell cycle in regulating the Invadopodia state. Using real-time imaging of cell cycle and invadopodia markers in vitro and in vivo, this Aim tests the hypothesis that cyclin- dependent kinases and corresponding inhibitors regulate the Invadopodia state, but not the Locomotion. Aim 2. Determine the role of ECM-cancer cell interactions in regulating the oscillations between Invadopodia and Locomotion states. This Aim will provide a strategy based on in vivo modification of integrin β1 activity on how to turn Invadopodia state ”off” towards metastatic prevention. Significance. Invadopodia is suggested as a new candidate target for metastatic prevention. The use of cell cycle inhibitors in patients with invadopodia may be accelerating metastatic dissemination. The long- term goal is to predict and prevent metastasis using invadopodia.