Prostate Cancer Bone Metastasis Biology and Targeting

描述(申请人提供)：抗去势前列腺癌(CRPC)患者常发生致死性骨转移。关键的是，这种情况的生物学原因仍然不确定。我们目前资助的计划项目赠款(PPG)专注于表征选定的可溶性因子，即癌细胞和肿瘤微环境中的癌细胞和细胞分泌的硫酸乙酰肝素蛋白多糖(HSPG)和活性氧物种(ROS)，以开发预测PC进展和治疗反应的生物标记物。我们在当前资助期间的进展包括几项专利和多种抗体的开发，这些抗体识别HSPG片段作为诊断/预后生物标记物的潜在商业化。我们还人源化了一种针对β-2微球蛋白的治疗性抗体，用于临床翻译治疗PC骨转移。在这个竞争性的更新应用中，我们重新定义的长期目标是在肿瘤微环境中追求新的概念，将肿瘤细胞重新定向到转移表型。这些创新包括发现(1)转移可以由转移起始细胞(MICS)协调(项目1：Chung)，(2)HSPG perlecan及其降解产物是PC转移的关键介质(项目2：Farach-Carson)，(3)具有巨核细胞和/或拟骨(MO-模仿)特性的细胞驻留在原发瘤中，并且可以被基质因素改变而转移到骨骼(项目3：Bhowmick)；以及(4)PC基因组的表观遗传编程可以以促进转移的方式影响胆固醇和固醇代谢(项目4：Freeman)。为了测试这些概念，我们将使用我们团队独有的方法和资源。我们发现，MICS可以通过涉及RANK介导的信号网络的前馈作用对非转移性休眠细胞进行重新编程，刺激它们参与骨定植。这一新的概念得到了来自动物模型和独特的荷尔蒙天真PC患者的大量数据的支持，这些患者患有骨转移，并从已知总存活率的患者中收集病理标本。我们将继续探索循环肿瘤细胞(CTCs)和播散性肿瘤细胞(DTC)(项目1-Chung)以及内皮细胞和炎症细胞(项目2)如何被招募参与转移级联的潜在生物学。我们建议开发生物标记物来预测哪些患者将从惰性疾病转变为侵袭性疾病。我们的长期目标将通过识别汇聚在关键节点的信号通路来实现，这些关键节点可以作为药物的靶向。我们的团队开发了一系列最先进的方法和工具，包括使用NanoVelcro微流体分离肿瘤细胞的单细胞方法、全基因组测序、多重量子点标记(MQDL)定量IHC、芯片序列分析和RNA-序列分析。我们已经成功地进行了人DTC的3D培养，由工程人和小鼠细胞组成的组织重组，以及可靠的人PC骨和软组织转移模型。

DESCRIPTION (provided by applicant): Lethal bone metastasis frequently develops in patients with castration-resistant prostate cancer (CRPC). Critically, the biology of this conditio remains uncertain. Our currently funded Program Project Grant (PPG) focuses on characterizing selected soluble factors, heparan sulfate proteoglycans (HSPG) and reactive oxygen species (ROS) secreted by cancer cells and cells in the tumor microenvironment, to develop biomarkers to predict PC progression and treatment response. Our progress during the current funding period includes several patents and the development of multiple antibodies recognizing HSPG fragments for potential commercialization as diagnostic/ prognostic biomarkers. We also humanized a therapeutic antibody against β2-microglobulin for clinical translation to treat PC bone metastasis. In this competitive renewal application, our long-term redefined goal is to pursue new concepts in the tumor microenvironment that redirect tumor cells toward a metastatic phenotype. These innovations include the discoveries that (1) metastasis can be coordinated by Metastasis Initiating Cells (MICs) (Project 1: Chung), (2) the HSPG perlecan and its degradative products are critical mediators of PC metastasis (Project 2: Farach-Carson); (3) cells with megakaryocyte and/or osteomimetic (MO-mimicry) properties reside in primary tumors and can be altered by stromal factors to metastasize to bone (Project 3: Bhowmick); and (4) epigenetic programming of the PC genome can affect cholesterol and sterol metabolism in a manner that promotes metastasis (Project 4: Freeman). To test these concepts, we will use approaches and resources unique to our team. We showed that MICs can reprogram non-metastatic dormant cells through a feed-forward action involving a RANK-mediated signaling network, provoking them to participate in bone colonization. This novel concept is supported by substantial data from animal models and a unique population of hormone-naïve PC patients with bone metastasis and pathologic specimens collected from patients with known overall survival. We will pursue the underlying biology of how circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) (Project 1- Chung), and endothelial and inflammatory cells (Project 2), are recruited to participate in the metastatic cascade. We propose to develop biomarkers to predict which patients will switch from indolent to aggressive disease. Our long range objectives will be achieved by identifying signaling pathways converging on critical nodes that can be targeted with drugs. Our team has developed a range of state-of-the-art methods and tools, including single cell methods of tumor cell isolation using NanoVelcro microfluidics, whole genome sequencing, quantitative IHC by multiplex quantum dot labeling (mQDL), ChIP-seq and RNA-seq analyses. We have demonstrated success in 3D culture of human DTCs, tissue recombinants comprised of engineered human and murine cells, and reliable models of human PC bone and soft tissue metastases.