Microfluidic tumor models to analyze the role of physicochemical cues in the angi

描述（申请人提供）：血管生成开关在肿瘤血管化和转移中起着基础作用；然而，微环境条件调节这一过程的潜在细胞和分子机制尚不清楚。该项目将解决这样一个假设，即不同肿瘤样壁龛的产生和这些壁龛内细胞之间的串扰上调了关键肿瘤细胞因子的表达，这些细胞因子有助于骨髓来源的内皮祖细胞（EPCs）的募集和肿瘤血管生成的增强。为了解决我们的假设，我们将利用基于物理科学的癌症生物学方法，结合三维细胞培养、微流体和数学建模。我们的研究设计基于4个目标：在目标1中，我们将设计3-D微流体肿瘤培养物，这将使我们能够测试这样的假设，即由空间解决的氧张力差异调节的可溶性因子信号，提供了一种跨壁龛的旁分泌机制，以调节肿瘤细胞和基质细胞细胞因子的差异表达。在目的2中，我们将评估肿瘤和基质细胞信号传导的全局和局部动态是否影响侵袭性血管生成，如目的1所阐明的那样。为此，我们将扩展目标1中开发的微流控平台，以集成内皮化微通道。该系统将是可重塑的，可以调整以显示增强的基质刚度，如典型的肿瘤基质。在目标3中，我们将确定目标2中定义的新血管形成的物理化学介导的变化是否会导致血管生态位的形成，从而影响内皮祖细胞的表型特征、时空贡献、生物学功能及其在肿瘤血管生成中的作用。最后，在目标4中，我们将对整合在微流控微血管中的EPCs进行动态全局转录组和表观基因组分析。生成的数据将被纳入计算信号转导网络分析，以确定可能负责血管生成开关中物理化学介导的变化的分子靶标。我们提出的研究有可能通过加强我们对肿瘤血管生成开关的理解，确定可能参与这一过程的分子机制，并提供治疗相关的靶点，来改进当前的抗血管生成治疗策略。

DESCRIPTION (provided by applicant): The angiogenic switch plays a fundamental role in tumor vascularization and metastasis; however, the underlying cellular and molecular mechanisms by which microenvironmental conditions regulate this process are still unclear. This project will address the hypothesis that the creation of distinct tumor-like niches and crosstalk between cells residing within these niches up-regulates expression of pivotal tumor cytokines that contribute to the recruitment of bone marrow-derived endothelial progenitor cells (EPCs) and enhanced tumor angiogenesis. To address our hypothesis we will utilize a physical-sciences based cancer biology approach that combines 3-D cell culture, microfluidics, and mathematical modeling. Our study design is based on 4 aims: In aim 1, we will design 3-D microfluidic tumor cultures that will allow us to test the hypothesis that the signaling of soluble factors, as regulated by spatially resolved differences in oxygen tension, provides a paracrine mechanism that spans between niches to regulate the differential expression of cytokines by both tumor and stromal cells. In aim 2, we will evaluate whether the global and local dynamics of tumor and stromal cell signaling, as elucidated in aim 1, impact invasion angiogenesis. To this end, we will expand the microfluidic platform developed in aim 1 to integrate endothelialized microchannels. This system will be remodelable and can be adjusted to exhibit enhanced matrix stiffness as typical of the tumor stroma. In aim 3, we will determine whether physicochemically mediated changes in neovessel formation as defined in aim 2 lead to the formation of vascular niches that impact the phenotypic identity, spatial and temporal contribution, and biological function of EPCs and their role in tumor angiogenesis. Finally, in aim 4, we will conduct dynamic global transcriptome and epigenome analysis of EPCs that have incorporated in the microfluidic microvessels. The generated data will be incorporated into computational signal transduction network analysis to identify molecular targets that may be responsible for physicochemically mediated changes in the angiogenic switch. Our proposed studies have the potential to improve current strategies of anti-angiogenic therapies by enhancing our understanding of the tumor angiogenic switch and identifying molecular mechanisms that may be involved in this process and provide therapeutically relevant targets. PUBLIC HEALTH RELEVANCE: Tumor angiogenesis represents a critical event of cancer that involves the recruitment of bone marrow derived endothelial progenitor cells; however, the exact mechanisms and effects by which microenvironmental conditions regulate these processes are not well understood. Using micropathological 3-D tumor models and mathematical modeling approaches this research will address the hypothesis that the creation of oxygen dependent tumor niches, and paracrine cellular crosstalk between these niches, up-regulates expression of pivotal tumor cytokines that impact invasion angiogenesis and the recruitment of endothelial progenitor cells. This interdisciplinary strategy has the potential to revolutionize our understanding of tumor vascularization and elucidate fundamentally new mechanisms of pro-angiogenic activity in cancers that could form a basis for improved anti-angiogenic therapies and clinical outcomes.