Heparan Sulfate Proteoglycans in Bone Stromal Metastasis

间质细胞影响前列腺癌(Pca)细胞，并通过与Pca细胞的相互作用而改变 在侵袭和转移的所有阶段，最终导致PCa在骨的定植。互动 在转移性前列腺癌壁龛中存在的细胞中，包括骨，是这个项目的重点， 重点介绍与硫酸乙酰肝素(HS)结合的蛋白多糖Pin，分子， 以及支持前列腺癌生长和进展的HS结合蛋白的受体。我们假设两者都是 反应性间质中Pin表达的增加和Pca细胞对Pin的降解支持侵袭性 侵袭性前列腺癌细胞的生长。为了准确定义Pin的结构和功能角色，它的各种 结构域及其相关的HS链在前列腺癌的骨转移中发挥作用，我们将使用一个 结合生化方法、体外模型、小鼠模型和临床标本来解决 具体目标如下：1)利用二维和三维细胞培养、动物模型和临床标本 检测导致Pin基因转录和表达增加的分子机制 反应性基质细胞、骨髓基质细胞和在骨中进行转分化的PCA细胞。 利用这些信息评估通路抑制剂降低Pin及其相关基因表达的能力 信号网络改变基因表达，支持PCa生长，并有利于推进Pca的定植 骨头。2)检测侵袭性PCa细胞激活的分解代谢酶对Pin的降解 转移的生态位，并确定发生的功能变化。细胞外支架的丢失 功能完整的Pin和b.)由于生物活性而获得生长、血管生成和转分化功能 通过HS链的分解代谢释放的PIN衍生的蛋白水解物片段和结合分子。3)评估 识别Pin降解产生的新表位作为新敏感性的抗体的有用性 首先在临床前动物模型中检测在骨中生长的侵袭性PCA细胞的诊断，然后在 自发性前列腺癌患者的标本。总之，这些相互交织的目标将使我们能够评估 PIN的表达、分解代谢、激活以及HS依赖的生长和进展最终导致PCa 骨转移灶。 相关性(请参阅说明)： 最近的数据支持这一范式转变的结论，即骨髓基质细胞的变化 周围生长在骨骼中的前列腺癌细胞为治疗前列腺癌提供了两个翻译机会， 能够：1)跟踪反应性间质的变化，作为肿瘤生长和侵袭的早期指标 2)在反应性间质中激活的靶向通路作为肿瘤生长的新干预措施 并在侵袭性表型建立后疾病进展。我们将把基础和基础相结合 实现这些双重目标的翻译方法。

Stromal cells affect prostate cancer (PCa) cells and are themselves altered by interactions with PCa cells during all phases of invasion and metastasis, ultimately leading to PCa colonization of bone. Interactions among the cells present in the metastatic PCa niche, including bone, are the focus of this project, with emphasis on the heparan sulfate proteoglycan perlecan, Pin, molecules that bind to heparan sulfate (HS), and receptors for HS binding proteins which support PCa growth and progression. We hypothesize that both increases in Pin expression in the reactive stroma and Pin degradation by the PCa cells support aggressive growth of invasive PCa cells. To precisely define the structural and functional roles that Pin, its various domains and its associated HS chains play in skeletal metastasis of prostate cancer, we will use a combination of biochemical approaches, in vitro models, mouse models and clinical specimens to address the following specific aims: 1) Use 2-D and 3-D cell culture, animal models and clinical specimens to examine the molecular mechanisms leading to increases in Pin gene transcription and expression by reactive stromal cells, bone marrow stromal cells, and by PCa cells undergoing transdifferentiation in bone. Use the information to evaluate pathway inhibitors for the ability to reduce Pin expression and its associated signaling networks that alter gene expression, support PCa growth and favor progression to colonization of bone. 2) Examine the degradation of Pin by catabolic enzymes activated by invasive PCa cells in the metastatic niche and to identify the functional changes which occur by a.) loss of the extracellular scaffolding function of intact Pin and b.) gain of growth, angiogenic and transdifferentiating functions owed to bioactive Pin -derived proteolytic fragments and binding molecules released by catabolism of HS chains. 3) Evaluate the usefulness of antibodies recognizing neoepitopes created by Pin degradation as new sensitive diagnostics for detection of invasive PCa cells growing in bone, first in pre-clinical animal models, then in specimens from PCa patients. Together, these interwoven aims will allow us to evaluate the link between Pin expression, catabolism, activation and HS-dependent growth and progression of PCa ultimately to the bone metastatic niche. RELEVANCE (See instructions): Recent data support the paradigm shifting conclusion that changes in the bone marrow stromal cells surrounding prostate cancer cells growing in bone provide two translational opportunities for treating PCa, the ability to: 1) follow changes in reactive stroma as early indicators of tumor growth and invasion at secondary sites; and 2) target pathways activated in reactive stroma as novel interventions of cancer growth and disease progression after an invasive phenotype has been established. We will combine basic and translational approaches to achieve these dual goals.