Heparan Sulfate Proteoglycans in Bone Stromal Metastasis

基质细胞影响前列腺癌（PCa）细胞，并且其自身通过与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。相互作用 在转移性前列腺癌壁龛中存在的细胞中，包括骨，是该项目的重点， 强调硫酸乙酰肝素蛋白聚糖串珠素，Pin，与硫酸乙酰肝素（HS）结合的分子， 以及支持PCa生长和进展的HS结合蛋白的受体。我们假设 反应性基质中Pin表达的增加和PCa细胞对Pin的降解支持了侵袭性前列腺癌的发生。 侵袭性PCa细胞的生长。为了精确定义Pin的结构和功能角色， 结构域及其相关的HS链在前列腺癌骨转移中的作用，我们将使用 生物化学方法、体外模型、小鼠模型和临床标本的组合， 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， 研究导致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经历转分化的PCa细胞。 使用这些信息评估通路抑制剂降低Pin表达的能力及其相关的 改变基因表达的信号网络，支持PCa生长并有利于PCa定植的进展。 骨头2)检测在前列腺中侵袭性PCa细胞激活的分解代谢酶对Pin的降解。 转移小生境，并确定发生的功能变化a.）细胞外支架丢失 完整销的功能和B.）由于生物活性物质， 钉衍生的蛋白水解片段和通过HS链的催化释放的结合分子。3)评价 识别由Pin降解产生的新表位的抗体作为新的敏感性抗体的有用性 用于检测骨中生长的侵袭性PCa细胞的诊断，首先在临床前动物模型中，然后在 来自PCa患者的标本。这些相互交织的目标将使我们能够评估 前列腺癌的Pin表达、分解代谢、激活和HS依赖性生长和进展最终导致前列腺癌的发生 骨转移灶 相关性（参见说明）： 最近的数据支持范式转变的结论，即骨髓基质细胞的变化 在骨中生长的周围前列腺癌细胞为治疗PCa提供了两种转化机会， 能够：1）跟踪反应性基质的变化，作为肿瘤生长和侵袭的早期指标， 次级位点;和2）在反应性基质中激活的靶向途径作为癌症生长的新干预 以及在已经建立侵袭性表型之后的疾病进展。我们将结合联合收割机的基本和 翻译方法来实现这些双重目标。

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.