ECM geometrical and mechanical properties modulate RTK signaling

 描述（由申请人提供）：受体酪氨酸激酶（RTK）扩增或RTK信号通路的一种或多种组分的不适当激活发生在许多侵袭性、治疗抗性肿瘤中，包括三阴性乳腺癌、肺癌和胰腺癌。RTK信号传导的临床重要性促使了设计用于阻断受体活化和下游信号传递的靶向疗法的开发。RTK抑制剂可以有显着的短期效益，但患者经常出现复发性，RTK抑制剂耐药肿瘤。我们的目标是了解这种治疗失败的根本原因。由于细胞间的相互作用， 遗传或表观遗传RTK信号传导异质性。细胞外基质（ECM）肿瘤微环境是物理和生物化学异质性，我们和其他人发现ECM的空间机械特征对RTK信号传导产生深远的影响。这是我们的论文，除了遗传变异，从ECM的外部空间机械因素是RTK治疗阻力的一个关键原因。我们预测，ECM环境小生境可能会保护一些癌细胞免受RTK抑制剂治疗，从而有利于肿瘤克隆的生存，并提高这些恶性细胞发生“有益”突变的可能性，这些突变会增加它们的侵略性，并最终危及患者的生存。然而，来自ECM的空间机械线索调节RTK信号传导的分子机制仍不清楚。格罗夫斯实验室已经开发出强大的支持脂质膜平台，以研究蛋白质在信号组装中的动力学，无论是在重建还是在与活细胞的混合连接中。使用这些系统，格罗夫斯和他的同事证明，RTK的空间组织和它们在质膜上的效应物调节信号转导的启动。Weaver小组拥有一系列2维和3维器官型培养系统和一套新型转基因小鼠模型，其中ECM力学和地形学以及糖萼可以控制，从而能够在培养和体内进行精确研究。Weaver表明ECM力学和地形学以及缺氧诱导的大体积糖萼改变RTK信号传导;可能是通过改变膜几何形状和RTK效应物活性。在这里，格罗夫斯和韦弗联合收割机结合他们的专业知识，以测试特定的分子机制，空间机械线索从ECM改变RTK信号。他们将把重点放在拉斯;一个GTdR作为一个关键的RTK信号节点，并询问物理调制对Ras激活的影响，在他们的脂质双层，细胞，和体内平台。这些研究将揭示细胞微环境调节RTK信号传导并有助于治疗抗性的分子机制。从这一理解，耦合本身的分子机制将成为新的目标，以减少癌症患者中RTK抑制剂耐药的发生率。

 DESCRIPTION (provided by applicant): Receptor tyrosine kinase (RTK) amplification or inappropriate activation of one or more components of the RTK signaling pathway occur in many aggressive, treatment resistant tumors including triple negative breast cancer, and lung and pancreatic cancers. The clinical importance of RTK signaling has motivated the development of targeted therapies designed to block receptor activation and downstream signal transmission. RTK inhibitors can have dramatic short-term benefits, however patients frequently present with recurrent, RTK inhibitor resistant tumors. Our goal is to understand the fundamental origins of this therapeutic failure. Treatment resistance can arise due to cell-to-cell genetic or epigenetic RTK signaling heterogeneity. The extracellular matrix (ECM) tumor microenvironment is physically and biochemically heterogeneous and we and others find that the spatial-mechanical features of the ECM exert profound effects on RTK signaling. It is our thesis that in addition to genetic variation, external spatial-mechanical factors from the ECM are a critical cause of RTK therapy resistance. We predict that ECM environmental niches may protect some cancer cells from RTK inhibitor treatments, thus favoring the survival of tumor clones and enhancing the probability of these malignant cells developing `beneficial' mutations that increase their aggression and ultimately compromise patient survival. Yet, the molecular mechanisms whereby spatial-mechanical cues from the ECM regulate RTK signaling remain unclear. The Groves lab has developed robust supported lipid membrane platforms to study dynamics of proteins in signaling assemblies, both in reconstitution and in hybrid junctions with living cells. Using these systems Groves and colleagues demonstrated that the spatial organization of RTKs and their effectors at the plasma membrane modulate signal transduction initiation. The Weaver group has an arsenal of 2- and 3-dimensional organotypic culture systems and a suite of novel transgenic mouse models in which ECM mechanics and topography and the glycocalyx can be controlled, enabling precision studies in culture and in vivo. Weaver showed that ECM mechanics and topography and a hypoxia induced bulky glycocalyx alter RTK signaling; likely by altering membrane geometry and RTK effector activity. Here Groves and Weaver combine their expertise to test specific molecular mechanisms by which spatial-mechanical cues from the ECM alter RTK signaling. They will focus on Ras; a GTPase as a key RTK signaling node and interrogate the impact of physical modulations on Ras activation in their lipid bilayer, cellular, and in vivo platforms. These studies will reveal te molecular mechanisms by which the cellular microenvironment modulates RTK signaling and contributes to treatment resistance. From this understanding, the molecular mechanisms of coupling themselves will emerge as new targets to reduce incidence of RTK inhibitor resistance in cancer patients.