Neuroendocrine Cancer: Tumor Regulation by PTHrP In Vitro and In Vivo

描述（由申请人提供）： 我们的总体假设是，PTHrP（甲状旁腺激素相关蛋白）在前列腺癌中的过表达的特征在于从该癌蛋白的三种天然亚型产生新的癌症特异性肽，并且这些新的肽可以调节肿瘤发生以及前列腺癌的生长和进展，特别是在骨骼中。我们的总体目标是确定这些肽及其对生长调节和肿瘤进展的影响，以充分了解这种恶性肿瘤的病理生物学。具体目标1。鉴定并充分表征源自前列腺癌中天然PTHrP多肽的PTHrP肽。我们将鉴定和表征前列腺癌产生的PTHrP肽。这将通过多方面的方法来实现，包括（a）免疫化学程序，如免疫亲和层析、多位点免疫测定和免疫组织化学，包括Western和（B）基于质谱（MS）的生化程序。这些方法将通过PTHrP的额外分子研究来补充。预期结果总结：我们希望确定PTHrP的前列腺特异性肽介导的前列腺癌的生长和增殖相关方面的影响。除了PTHrP的经典肽，我们希望发现新的肽，可以发挥其分子作用，通过新的分子途径。具体目标2。确定这些PTHrP处理肽如何调节骨骼和其他部位的前列腺癌进展。通过肽处理和通过将前列腺癌细胞直接植入骨和其他部位来在免疫受损的小鼠中实现该目的，所述前列腺癌细胞已经被基因工程改造用于PTHrP表达以分别显示PTHrP及其肽的生长调节作用。新的成像程序将用于监测肿瘤的行为。这些模型将使我们能够研究PTHrP各自的作用和介导前列腺癌体内进展的分子相互作用。预期结果总结：我们期望在我们的前列腺癌动物模型中鉴定PTHrP肽，其调节前列腺癌的骨骼和非骨骼进展。我们希望根据目标1的相应体外研究以及我们在该领域的初步结果，为这些体内研究提供信息和重点。我们期望在体内鉴定和阐明PTHrP及其衍生肽的生长调节结构域，从而促进利用这些机制来开发肿瘤的诊断和治疗靶点。 公共卫生相关性： 我们研究PTHrP（甲状旁腺激素相关蛋白）在前列腺癌中对退伍军人健康的重要性显而易见，因为这是我们患者中最常见的癌症之一。此外，我们的研究可以提供有关其他常见PTHrP表达癌症的基本和临床信息，这些癌症与退伍军人有关，包括乳腺癌、肺癌和造血系统恶性肿瘤，如骨髓瘤。我们提出的研究将提供有关PTHrP在癌症中的生长调节特性的基本信息。这些基本信息可以转化为临床应用，用于这些肿瘤的管理和诊断。另见研究计划第2节C项。

DESCRIPTION (provided by applicant): It is our overall Hypothesis that PTHrP (parathyroid hormone related protein) overexpression in prostate cancer is characterized by the generation of novel, cancer-specific peptides from the three native isoforms of this oncoprotein and that these novel peptides can regulate tumorigenesis and the growth and progression of prostate cancer, especially in the skeleton. Our overall Aim is to identify these peptides and their effects on growth-regulation and tumor progression in order to fully understand the pathobiology of this malignancy. Specific Aim 1. To identify and fully characterize the PTHrP peptides that are derived from the native PTHrP polypeptides in prostate cancer. We shall identify and characterize the PTHrP peptides produced by prostate cancers. This will be accomplished by a multifaceted approach that includes (a) immunochemical procedures like immunoaffinity chromatography, multi-site immunoassays, and immunohistochemistry, including Westerns and (b) biochemical procedures based on mass spectrometry (MS). These methods will be complemented by additional molecular studies of PTHrP. Summary of Expected Results: We expect to identify prostate-specific peptides of PTHrP that mediate effects on growth- and proliferation-related aspects of prostate cancer. In addition to PTHrP's classical peptides, we expect to discover new peptides that can exert their molecular action though novel molecular pathways. Specific Aim 2. To determine how these PTHrP-processed peptides regulate prostate cancer progression in skeletal and other sites. This aim will be accomplished in immunocompromised mice by peptide treatment and by directly implanting into bone and other sites prostate cancer cells that have been genetically engineered for PTHrP expression to respectively manifest the growth regulatory effects of PTHrP and its peptides. Novel imaging procedures will be used to monitor tumor behavior. These models will allow us to study PTHrP's respective effects and molecular interactions that mediate in vivo progression of prostate cancer. Summary of Expected Results: We expect to identify PTHrP peptides that regulate the respective progression, both skeletal and non-skeletal, of prostate cancer in our animal model for this tumor. We expect to inform and focus these in vivo studies based on the corresponding in vitro studies of Aim 1 as well as our Preliminary Results in this area. We expect to identify and elucidate the growth- regulatory domains of PTHrP and its derived peptides in vivo and to thus facilitate exploitation of these mechanisms for the development of diagnostic and therapeutic targets for the tumor. PUBLIC HEALTH RELEVANCE: The importance of our studies of PTHrP (parathyroid hormone related protein) in prostate cancer to Veterans Health is manifest, as this is one of the most common cancers among our patients. Furthermore, our studies may provide basic and clinical information about other common PTHrP-expressing cancers that are relevant to Veterans, including breast, lung, and hematopoetic malignancies like myeloma. The studies that we propose will provide fundamental information about the growth regulating properties of PTHrP in cancer. This basic information can be translated to clinical applications that can be used in the management and diagnosis of these tumors. See also Section 2, Item C of the Research Plan.