ETS1 AND FLI1 IN STROMAL ACTIVATION IN BREAST CANCER

反应性间质在肿瘤发生中起重要作用。为了方便招聘， 微血管和肿瘤细胞的迁移细胞外基质（ECM）必须经历广泛的 重塑介导细胞外基质在静息状态下转换的分子机制 间质，并负责在肿瘤发生过程中这一过程的失调还没有得到很好的定义。那里 越来越多的证据，包括我们实验室最近的研究，表明Ets家族的成员，Flil和 Etsl是健康组织中基质稳态的关键调节剂，也是形成 反应性间质。我们假设Fli 1参与维持静止的间质， 健康组织血管中内皮细胞和血管周围细胞之间的适当相互作用。下调 Flil和Etsl的上调有助于乳腺肿瘤中的新血管生成。具体来说，我们假设 Ets因子作为TGF-β/CTGF和Ras-MAPK信号通路的整合剂的主要作用是 调节ECM重塑。这反过来又影响细胞迁移、细胞存活和 血管周细胞到新形成的血管。为了验证这些假设，我们提出了三个具体目标。在 目的1探讨Flil和Etsl在人微血管内皮细胞凋亡中的作用 细胞（HVMECs）。在目标2中，我们将采用HVMEC和乳腺癌的体外器官型共培养， 成纤维细胞中，以研究Etsl和Flil在毛细血管网络形成中的作用。具体来说，影响力 将使用该3D模型检查TGF-β、CTGF和肿瘤衍生因子的表达。在目标3中， 使用不同的遗传模型确定Flil在Neu-induced乳腺肿瘤发生中的作用， Flil表达式。这些将包括现有的Flil+/-小鼠和条件性组织特异性Flil缺失 突变体的纤维母细胞和内皮细胞，这将在这个项目中产生。在3D中获得的结果 共培养实验和体内动物模型将使用来自乳腺癌患者的组织进行验证。 癌

The reactive stroma plays an important role in tumorigenesis. In order to facilitate recruitment of the microvasculature and migration of tumor cells extracellular matrix>(ECM) must undergo extensive remodelling. The molecular mechanisms that mediate controlled regulation of ECM turnover in quiescent stroma and are responsible for dysregulation of this process during tumorigenesis are not well defined. There is growing evidence, including recent studies from our laboratory, that the members of the Ets family, Flil and Etsl, are the critical regulators of stromal homeostasis in healthy tissues, as well as contributors to formation of reactive stroma. We hypothesize that Fli 1 is involved in maintaining quiescent stroma, which facilitates proper interactions between endothelial and perivascular cells in healthy tissue blood vessels. Downregulation of Flil and upregulation of Etsl contributes to neoangiogenesis in breast tumors. Specifically, we hypothesize that the primary role of Ets factors as integrators of the TGF-P/CTGF and Ras-MAPK signalling pathways is in regulation of ECM remodeling. This in turn affects cell migration, cell survival, and recruitment of perivascular cells to the newly formed vessels. To test these hypotheses we propose three Specific Aims. In Aim 1 we will determine the possible role of Flil and Etsl in apoptosis of human microvascular endothelial cells (HVMECs). In Aim 2 we will employ an in vitro organotypic coculture of HVMECs and breast fibroblasts to investigate the roles of Etsl and Flil in capillary network formation. Specifically, the influence of TGF-p, CTGF, and tumor-derived factors will be examined using this 3D model. In Aim 3 we will determine the role of Flil in Neu-induced mammary tumorigenesis using various genetic models with altered Flil expression. These will include an existing Flil+/- mice and conditional tissue-specific Flil deletion mutants in fibroblasts and endothelial cells, which will be generated in this project. The results obtained in 3D coculture experiments and in animal models in vivo will be validated using tissue from patients with breast cancer.