Identification of Proteins Mediating Prostate Cancer

描述(申请人提供)：前列腺癌转移到骨的分子机制还不是很清楚，调节这一过程的配体-受体系统在很大程度上也是未知的。本文提出了一种基于强大的平台技术的综合方法，该方法将用于剖析转移性前列腺癌细胞与骨髓相互作用的分子机制。最近建立的癌症患者随机肽噬菌体展示文库的筛选使快速分离特定组织血管系统的配体成为可能。我们建议使用从前列腺癌患者中分离的骨髓归巢多肽作为线索来鉴定介导前列腺癌表达的骨转移的人细胞表面蛋白。将使用一种增强的体内噬菌体展示试验，平行生物扫描来分离归巢于人骨髓的多肽基序。包含骨髓归巢基序的相应前列腺癌细胞表面蛋白将使用专门设计的生物信息学平台进行鉴定。对于几种被证实对骨髓具有高亲和力和特异性的多肽，基于它们的培养和原位检测，我们建议为可能的前列腺癌标记物确定相应的骨髓受体。对于受体的鉴定，我们将使用先前建立的候选受体方法、传统生物化学和噬菌体双杂交系统的组合：一种最近开发的分离相互作用蛋白的方法。因此，这项研究有望确定至少一个或两个配体-受体对，它们可能是已建立的或尚未确定的蛋白质，介导转移性前列腺癌细胞向骨骼的归巢。在未来，通过确定它们在疾病背景下表达的选择性，所识别的分子可以被验证为前列腺癌分析和干预的潜在生物医学靶点。在优化后，这一方法可能被简化为系统地描述肿瘤细胞-骨髓相互作用的分子多样性，以评估预后和/或用于个体转移性前列腺癌的治疗。

DESCRIPTION (provided by applicant): Molecular mechanisms of prostate cancer metastasis to the bone are not well understood, and the ligand-receptor systems mediating this process are largely unknown. Proposed here is an integrated approach based on powerful platform technologies that will be used to dissect the molecular mechanisms of interaction between metastatic prostate cancer cells and the bone marrow. Recently established screening of random peptide phage display libraries in cancer patients enables quick isolation of ligands that can home to the vasculature of specific tissues. We propose to use bone marrow-homing peptides isolated in prostate cancer patients as leads for identification of human cell surface proteins mediating bone metastasis expressed by malignant prostate tumors. Peptide motifs homing to human bone marrow will be isolated using an enhanced in vivo phage display assay, parallel biopanning. The corresponding prostate cancer cell surface proteins containing the bone marrow-homing motifs will be identified using a specially designed bioinformatics platform. For several peptides validated to have high affinity and specificity for bone marrow, based on their testing in culture and in situ, we propose to identify the corresponding bone marrow receptors for the putative prostate cancer markers. For receptor identification, we will use a combination of previously established candidate receptor approach, conventional biochemistry, and the phage two-hybrid system: a recently developed assay for isolation of interacting proteins. As a result, this study is expected to identify at least one or two ligand-receptor pairs, which may be established or yet uncharacterized proteins that mediate the homing of metastatic prostate cancer cells to the bone. In the future, the identified molecules can be validated as potential biomedical targets for prostate cancer profiling and intervention by determining selectivity of their expression in the context of the disease. Upon optimization, this approach may be streamlined to systematically profile the molecular diversity of tumor cell-bone marrow nteractions for assessment of prognosis and/or for treatment of metastatic prostate cancer in individual patients.