Profilin as a target to suppress invasive breast cancer

乳腺癌死亡率是由于远处器官的转移性受累，这在很大程度上是由增加的 侵略性以前的研究表明，在表达下调profilin（肌动蛋白结合蛋白 其也具有肿瘤抑制作用）。这一点，连同我们的 初步数据显示，过表达选择性受损的profilin或它的突变体， 肌动蛋白或富含脯氨酸基序（PRM）蛋白显著降低乳腺癌的迁移 细胞，导致一个假设，profilin的功能调节乳腺癌的侵袭和转移 （假设）。该项目的总体目标是确定如何利用profilin的扰动来 抑制乳腺癌侵袭和转移。为了检验假设，在目标I中，我们将首先使用一系列 分子结构来确定profilin功能的调节如何改变乳腺癌的迁移 细胞接下来，为了确定细胞迁移中profilin依赖性变化的分子基础，我们将 研究profilin的各种扰动如何改变细胞骨架结构和细胞的增殖能力。 细胞在Aim II中，我们将首先使用光操纵技术来确定profilin的功能是否是 在迁移细胞中空间受限。接下来，我们将选择性地消除profilin与不同的 PRM蛋白的类别，以确定乳腺癌细胞迁移中的关键PRM相互作用，然后使用 荧光共振能量转移（FRET）技术来研究这些时空方面 细胞迁移过程中的相互作用。在目标III中，我们将首先确定Profiin的扰动如何改变乳房 部分模拟肿瘤细胞-基质相互作用的体外环境中的癌细胞侵袭。最后利用 动物模型我们将测试profilin的扰动是否有效抑制乳腺癌转移。

Breast cancer mortality is due to metastatic involvement of distant organs driven in large part by increased invasiveness. Previous studies show downregulation in the expression of profilin (an actin-binding protein which also has a tumor-suppressive effect) in metastatic breast cancer cells. This, taken together with our preliminary data showing that overexpressing profilin or it'smutants that are selectively impaired in binding to either actin or proline-rich motif (PRM) proteins significantly decreases the migration of breast carcinoma cells, leads to a hypothesis that profilin's function regulates breast cancer invasion and metastasis (HYPOTHESIS). The overall goal of the project is determine how perturbations of profilin can be utilized to suppress breast cancer invasion and metastasis. To test the hypothesis, in Aim I, we will first use a series of molecular constructsto determine how modulations of profilin's function alter the migration of breast cancer cells. Next, in order to determine the molecular basis for profilin-dependent changes in cell migration, we will investigate how various perturbations of profilin alter the cytoskeletal structure and the protrusive ability of cells. In Aim II, we will first employ photomanipulative techniques to determine whether profilin's function is spatially restricted in migrating cells. Next, we will abolish profilin's interaction selectively with different classes of PRM proteins to identify the key PRM interactions in breast cancer cell migration, and then use fluorescence resonance energy transfer (FRET) technique to study the spatiotemporal aspects of these interactions during cell migration. In Aim III,we will first determine how perturbations of profiin alter breast cancer cell invasion in an in vitro milieu partially mimicking tumor cell-stromal interactions. Finally, using animal model we will test whether perturbations of profilin are effective in inhibiting breast cancermetastasis.