Syndecan-1 in Stromal Fibroblasts of Breast Carcinomas

描述（由申请人提供）：乳腺癌应被视为一个器官系统，其中生长和进展受肿瘤细胞和周围基质成分之间复杂和相互作用的控制。成纤维细胞，其中包括一个主要的基质细胞类型，维持正常乳腺组织的稳态，但促进乳腺癌的肿瘤进展。癌相关成纤维细胞（CAF）在形态、基因表达和分泌因子方面与正常乳腺成纤维细胞（NMF）不同。我们的实验室已经表明，在CAF中的细胞表面蛋白聚糖syndecan 1（Sdc 1）的表达在大多数乳腺癌中被诱导，并且Sdc 1刺激乳腺癌增殖。由于成纤维细胞的主要功能之一是组装细胞外基质（ECM），我们已经开始研究Sdc 1表达是否影响ECM合成。我们的初步数据表明，Sdc 1在CAF中的表达影响ECM支架的结构或精细结构。这是这个建议的目标，详细了解如何Sdc 1调节ECM组装在乳腺癌和什么后果Sdc 1依赖性ECM改变可能对癌的行为。基于我们的初步观察，我们提出以下假设：乳腺癌间质成纤维细胞Sdc 1的异常表达导致ECM结构改变，这是允许乳腺癌细胞侵袭。我们认为这种改变的ECM结构有助于疾病自然史早期和晚期的侵袭事件，并缩短患者的生存期。为了验证这一假设，我们提出了以下具体目标：目标1：检查Sdc 1和ECM结构在乳腺癌侵袭中的作用。将在人乳腺癌样品中仔细分析ECM结构。使用组织微阵列，我们将确定ECM结构特征是否预测患者预后。创新的离体入侵检测将告知我们Sdc 1和/或ECM结构是否调节入侵。最后，将用Sdc 1缺陷动物检查Sdc 1在确定ECM结构中的参与。目的2：分析Sdc 1和ECM在导管原位癌（DCIS）向浸润癌发展过程中的作用。通过将新的ECM成像工具应用于人类样本和DCIS动物模型，我们将确定基质Sdc 1表达是否产生了促进DCIS进展为浸润性癌的侵袭许可ECM。目的3阐明细胞外基质形成的分子机制。特定Sdc 1分子结构域参与调节ECM组装将在体外用结构域缺失和取代实验进行分析。整合素细胞粘附受体的协同作用将通过功能丧失和功能获得实验进行研究。总之，这些目标将显着推进我们对乳腺癌中ECM产生调节的认识。对ECM组装的机械理解是设计新型治疗剂的关键，所述新型治疗剂旨在使ECM“正常化”，从而将肿瘤微环境从侵袭许可性恢复为侵袭限制性。 公共卫生相关性：美国每年约有20万例新诊断病例，乳腺癌是并仍然是一个主要的健康问题。即使有先进的治疗选择，每年仍有4万名妇女死亡。我们的项目旨在了解乳腺癌中结缔组织支架的结构是如何调节的，以及它如何影响癌症的侵袭和扩散。这项工作产生的知识可能会导致针对这种支架结构的新疗法，并防止癌细胞逃逸。

DESCRIPTION (provided by applicant): Breast cancer should be viewed as an organ system in which growth and progression are governed by complex and reciprocal interactions between tumor cells and surrounding stromal elements. Fibroblasts, which comprise a predominant stromal cell type, maintain tissue homeostasis in normal breast but promote tumor progression in breast cancer. Carcinoma-associated fibroblasts (CAF) distinguish themselves from normal mammary fibroblasts (NMF) by morphology, gene expression and secreted factors. Our lab has shown that expression of the cell surface proteoglycan syndecan 1 (Sdc1) in CAF is induced in the majority of breast carcinomas and that Sdc1 stimulates breast carcinoma proliferation. Because one of the main functions of fibroblasts is the assembly of an extracellular matrix (ECM), we have begun to examine whether Sdc1 expression affects ECM synthesis. Our preliminary data indicate that Sdc1 expression in CAF influences the architecture, or fine structure, of the ECM scaffold. It is the goal of this proposal to understand in detail how Sdc1 regulates ECM assembly in breast carcinomas and what consequences Sdc1-dependent ECM alterations might have on carcinoma behavior. Based on our preliminary observations, we state the following hypothesis: The aberrant expression of Sdc1 by breast carcinoma stromal fibroblasts leads to an altered ECM architecture, which is permissive to breast carcinoma cell invasion. We posit that this altered ECM architecture contributes to invasion events early and late during the natural history of the disease and shortens patient survival. To test this hypothesis, we propose the following specific aims: Aim 1: Examine the role of Sdc1 and ECM architecture in breast carcinoma invasion. The ECM architecture will be carefully analyzed in human breast carcinoma samples. Using tissue microarrays, we will determine whether ECM architectural features predict patient prognosis. Innovative ex vivo invasion assays will inform us whether Sdc1 and/or the ECM architecture regulate invasion. Lastly, the involvement of Sdc1 in determining the ECM architecture will be examined with Sdc1-deficient animals. Aim 2: Analyze the role of Sdc1 and ECM architecture in the progression from ductal carcinoma in situ (DCIS) to invasive carcinoma. By applying novel ECM imaging tools to human samples and to a DCIS animal model, we will determine whether stromal Sdc1 expression creates an invasion-permissive ECM that facilitates progression from DCIS to invasive carcinoma. Aim 3 Decipher the molecular mechanisms responsible for the formation of an invasion-permissive ECM. The involvement of specific Sdc1 molecular domains in regulating ECM assembly will be analyzed in vitro with domain deletion and substitution experiments. The cooperative role of integrin cell adhesion receptors will be investigated with loss of function and gain of function experiments. Together, these aims will significantly advance our knowledge about the regulation of ECM production in breast cancer. A mechanistic understanding of ECM assembly is key to the design of novel therapeutic agents that are aimed at "normalizing" the ECM and thus revert the tumor microenvironment from invasion-permissive to invasion-restrictive. PUBLIC HEALTH RELEVANCE: With approximately 200,000 newly diagnosed cases in the US per year, breast cancer is and remains a major health issue. Even with the advanced treatment options available, 40,000 women die annually. Our project aims at understanding how the architecture of the connective tissue scaffold in breast cancer is regulated and how it affects cancer invasion and spread. The knowledge generated with this work may lead to novel therapies that target the structure of this scaffold and prevent the escape of cancer cells.