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)在前列腺癌中过表达的特征是该癌蛋白的三种天然亚型产生新的癌症特异性多肽，这些新多肽可以调节肿瘤的发生和前列腺癌的生长和进展，特别是在骨骼中。我们的总体目标是鉴定这些多肽及其对生长调节和肿瘤进展的影响，以便充分了解这种恶性肿瘤的病理生物学。具体目的1.鉴定和鉴定前列腺癌中天然的PTHrP多肽。我们将鉴定和表征前列腺癌产生的PTHrP多肽。这将通过一种多方面的方法来实现，其中包括：(A)免疫亲和层析、多部位免疫分析和免疫组织化学程序，包括Westns和(B)基于质谱仪(MS)的生化程序。这些方法将得到PTHrP的额外分子研究的补充。预期结果总结：我们希望确定PTHrP的前列腺特异性多肽，它们对前列腺癌的生长和增殖相关方面有中介作用。除了PTHrP的经典多肽外，我们还希望发现能够通过新的分子途径发挥其分子作用的新多肽。具体目的2.确定这些PTHrP处理的多肽如何调节骨骼和其他部位的前列腺癌进展。在免疫低下的小鼠中，这一目标将通过多肽治疗和直接植入骨和其他部位的前列腺癌细胞来实现，这些细胞已经被基因工程改造为PTHrP表达，以分别证明PTHrP及其多肽的生长调节作用。新的成像程序将被用于监测肿瘤的行为。这些模型将使我们能够研究PTHrP在体内介导前列腺癌进展的各自作用和分子相互作用。预期结果摘要：我们希望在前列腺癌的动物模型中识别调节前列腺癌的骨骼和非骨骼进展的PTHrP多肽。我们希望根据Aim 1的相应体外研究以及我们在这一领域的初步结果来通知和关注这些体内研究。我们期望在体内识别和阐明PTHrP及其衍生多肽的生长调节域，从而促进这些机制的开发，以开发肿瘤的诊断和治疗靶点。 公共卫生相关性： 我们对前列腺癌甲状旁腺激素相关蛋白(PTHrP)的研究对退伍军人健康的重要性是显而易见的，因为这是我们患者中最常见的癌症之一。此外，我们的研究可能提供与退伍军人相关的其他常见的PTHrP表达癌症的基本和临床信息，包括乳腺癌、肺癌和骨髓瘤等血液系统恶性肿瘤。我们提出的研究将提供关于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，可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.