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，其生长和进展受肿瘤细胞和周围基质元素之间复杂和相互作用的支配。成纤维细胞是一种主要的基质细胞类型，在正常乳腺中维持组织稳态，但在乳腺癌中促进肿瘤进展。癌相关成纤维细胞（CAF）通过形态、基因表达和分泌因子与正常乳腺成纤维细胞（NMF）区分。我们的实验室已经证明，在大多数乳腺癌中，CAF中细胞表面蛋白多糖syndecan 1 （Sdc1）的表达是被诱导的，并且Sdc1刺激乳腺癌的增殖。由于成纤维细胞的主要功能之一是细胞外基质（ECM）的组装，我们已经开始研究Sdc1的表达是否影响ECM的合成。我们的初步数据表明，Sdc1在CAF中的表达会影响ECM支架的结构或精细结构。本提案的目标是详细了解Sdc1如何调节乳腺癌中ECM的组装，以及Sdc1依赖性ECM改变可能对癌症行为产生的后果。基于我们的初步观察，我们提出以下假设：Sdc1在乳腺癌间质成纤维细胞中的异常表达导致ECM结构的改变，这有利于乳腺癌细胞的侵袭。我们假设这种改变的ECM结构有助于在疾病的自然历史中早期和晚期的入侵事件，并缩短患者的生存期。为了验证这一假设，我们提出以下具体目标：目的1：研究Sdc1和ECM结构在乳腺癌侵袭中的作用。ECM结构将在人类乳腺癌样本中仔细分析。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。创新的离体入侵试验将告诉我们Sdc1和/或ECM结构是否调节入侵。最后，Sdc1在确定ECM结构中的作用将在Sdc1缺失的动物中进行研究。目的2：分析Sdc1和ECM结构在导管原位癌（DCIS）向浸润性癌进展中的作用。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Sdc1表达是否会产生侵袭性ECM，从而促进从DCIS到浸润性癌的进展。目的3：破译入侵容许性ECM形成的分子机制。Sdc1分子结构域在体外调节ECM组装中的作用将通过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，这些目标将显著提高我们对乳腺癌中ECM产生调控的认识。对ECM组装机制的理解是设计新型治疗剂的关键，这些治疗剂旨在使ECM“正常化”，从而将肿瘤微环境从允许侵入恢复到限制侵入。

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.