Mechanisms of adhesion and invasion in hyaluronic acid matrices

项目总结/摘要 透明质酸（HA）是人脑中最丰富的成分，在人脑中它起着重要的结构， 机械和细胞指导功能。HA与其受体CD 44之间的粘附严重调节 HA和/或CD 44的发育和稳态以及失调导致许多脑病理， 包括致命的脑肿瘤胶质母细胞瘤（GBM）的侵袭。尽管具有明显的生物学意义， HA-CD 44粘附，相对而言，对HA-CD 44粘附的生物物理机制知之甚少。 CD 44相互作用驱动细胞粘附、迁移或基质重塑或HA组成（例如分子生物学）如何影响细胞粘附、迁移或基质重塑。 重量）影响粘附和迁移。在过去的十年里，我们的团队为以下方面做出了重大贡献： 解决这些问题，包括引入和完善合成3D HA基质作为培养模型， 研究GBM入侵我们还发现，CD 44转导基于HA的机械信号，以调节 细胞形状、细胞骨架组装和运动性。最近，我们发现GBM细胞通过使用 “微触角”（McTNs），从细胞体延伸数十微米的CD 44依赖性过程， 与HA消化相关，并通过一种复合物与细胞骨架机械偶联， IQGAP 1和CLIP 170。McTNs与在侵袭性肿瘤中观察到的结构具有重要的相似性。 GBM在体内，McTN组分的过表达是预测侵袭性进展和不良预后的指标。 在GBM中生存。在R 01申请中，我们将利用这些发现和生物材料平台， 促进该领域对HA和CD 44如何促进细胞粘附、迁移和侵袭的理解。在 我们的第一个目标是研究McTNs如何促进粘附、侵袭和基质重塑。在我们 第二个目标，我们将确定脑组织中HA网络的生物物理特征如何有助于3D 迁移，使用GBM作为模型系统。我们的方法的特点是紧密集成的工程 生物材料培养模型、以人GBM干细胞/起始细胞为特征的小鼠模型和活检分析 从人GBM的特定解剖区域获得。我们的多机构团队还独特地结合了 在生物材料、机械生物学、神经外科和癌症生物学方面的专业知识。成功完成这些 这些研究将对HA和CD 44在生物物理学基础上产生前所未有的深入了解， 粘附和侵袭，这是一个高度基本感兴趣的问题，可能导致新的治疗靶点， GBM。

PROJECT SUMMARY/ABSTRACT Hyaluronic acid (HA) is the most abundant component of the human brain, where it serves essential structural, mechanical, and cell-instructive functions. Adhesion between HA and its receptor CD44 critically regulates development and homeostasis, and dysregulation of HA and/or CD44 causally drives many brain pathologies, including invasion of the deadly brain tumor glioblastoma (GBM). Despite the clear biological significance of HA-CD44 adhesion, comparatively little is known about either the biophysical mechanisms through which HA- CD44 interactions drive cell adhesion, migration, or matrix remodeling or how HA composition (e.g. molecular weight) influences adhesion and migration. Over the past decade, our team has made seminal contributions to addressing these questions, including introducing and refining synthetic 3D HA matrices as a culture model for studying GBM invasion. We also discovered that CD44 transduces HA-based mechanical signals to regulate cell shape, cytoskeletal assembly, and motility. Most recently, we discovered that GBM cells engage HA using “microtentacles” (McTNs), CD44-dependenent processes that extend tens of microns from the cell body, are associated with HA digestion, and mechanically couple to the cytoskeleton through a complex that includes IQGAP1 and CLIP170. McTNs bear important similarities to structures that have been observed in invasive GBMs in vivo, and overexpression of McTN components is predictive of with aggressive progression and poor survival in GBM. In this R01 application, we will leverage these discoveries and biomaterial platforms to advance the field’s understanding of how HA and CD44 contribute to cell adhesion, migration, and invasion. In our first aim, we will investigate how McTNs facilitate adhesion, invasion, and matrix remodeling. In our second aim, we will determine how biophysical features of the HA network in brain tissue contributes to 3D migration, using GBM as a model system. Our approach is distinguished by tight integration of engineered biomaterial culture models, mouse models featuring human GBM stem/initiating cells, and analysis of biopsies obtained from specific anatomic regions of human GBMs. Our multi-institutional team also uniquely combines expertise in biomaterials, mechanobiology, neurosurgery, and cancer biology. Successful completion of these studies will yield unprecedented insight into the biophysical basis through which HA and CD44 contribute to adhesion and invasion, a problem of high fundamental interest that may lead to novel therapeutic targets in GBM.