Microglia promote dispersal of glioma cells through Pyk2 intracellular signaling

描述（由申请人提供）：多形性胶质母细胞瘤预后异常差，诊断后中位生存期约为一年，这在很大程度上是由于胶质瘤细胞的高度浸润行为否定了当前医学方法的有效性。小胶质细胞浸润大多数胶质瘤并释放影响肿瘤侵袭的因子。我们的初步数据表明，小胶质细胞释放的可溶性因子激活了人类和啮齿动物胶质瘤细胞系的迁移/侵袭，并上调了Pyk2的磷酸化。靶向Pyk2的siRNA消除了小胶质对胶质瘤细胞迁移的影响。基于这些数据，我们假设在肿瘤微环境中，小胶质细胞通过激活胶质瘤细胞内的Pyk-2信号通路释放可溶性因子，促进胶质瘤细胞向其他脑区迁移和扩散。在目前的研究中，我们将使用细胞生物学的方法来研究参与Pyk2激活/磷酸化的细胞内机制，以响应小胶质细胞释放的可溶性因子。我们还将在小鼠模型中检验Pyk2阻滞剂补充传统化疗胶质瘤治疗的有效性，以消除小胶质细胞对胶质瘤细胞扩散的影响。为了验证我们的假设，我们提出了以下具体目标：具体目标#1：验证小胶质细胞通过Pyk2细胞内通路激活胶质瘤细胞迁移/侵袭的假设。具体目标#2：验证磷脂酶C？1 (PLC) ?1)和表皮生长因子受体（EGFR）介导小胶质细胞激活的胶质瘤运动。特定目的#3：测试替莫唑胺（TMZ）和PF-562271联合治疗与目前单独治疗TMZ相比，在减少胶质瘤生长和扩散方面的有效性。我们假设的验证将为开发旨在防止胶质瘤细胞扩散到健康大脑区域的治疗策略提供一个平台。

DESCRIPTION (provided by applicant): Glioblastoma multiforme, carries an exceptionally poor prognosis with median survival of approximately one year following diagnosis, in large part, due to the highly infiltrative behavior of glioma cells negating the effectiveness of current medical approaches. Microglia infiltrate most gliomas and release factors which influence tumor invasion. Our preliminary data indicate that soluble factors, released by microglia activate migration/invasion and up regulate phosphorylation of Pyk2 in human and rodent glioma cell lines. siRNA targeting Pyk2 eliminates the microglial effect on glioma cell migration. Based on these data we hypothesize that in the tumor microenvironment microglia release soluble factors which promote migration and dispersal of glioma cells to other brain regions through activation of the Pyk-2 intracellular signaling pathway in glioma cells. In the present study using cell biology approaches, we will examine the intracellular mechanisms involved in Pyk2 activation/phosphorylation in response to soluble factors released by microglia. We will also examine, in a murine model, the effectiveness of supplementing traditional chemotherapeutic glioma treatment with a Pyk2 blocker in order to eliminate the effect of microglia on glioma cell dispersal. To test our hypothesis we propose the following specific aims: Specific Aim #1: To test the hypothesis that microglia activate migration/invasion of glioma cells through a Pyk2 intracellular pathway. Specific Aim #2: To test the hypothesis that phospholipase C?1 (PLC?1) and epidermal growth factor receptor (EGFR) mediate microglial activated glioma mobility. Specific aim #3: To test the effectiveness of combined treatment of temozolomide (TMZ) and PF-562271 in decreasing glioma growth and dispersal as compared to the current treatment of TMZ alone. Validation of our hypothesis will provide a platform for developing therapeutic strategies aimed at prevention of glioma cell dispersal into healthy brain regions.