Identification of Proteins Mediating Prostate Cancer

描述（由申请人提供）：前列腺癌骨转移的分子机制尚不清楚，介导该过程的配体-受体系统在很大程度上未知。 本文提出了一种基于强大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之间相互作用的分子机制。 最近在癌症患者中建立的随机肽噬菌体展示文库的筛选使得能够快速分离可以归巢到特定组织的脉管系统的配体。 我们建议使用从前列腺癌患者中分离的骨髓归巢肽作为鉴定恶性前列腺肿瘤表达的介导骨转移的人细胞表面蛋白的线索。 将使用增强的体内噬菌体展示测定、平行生物淘选来分离归巢至人骨髓的肽基序。 将使用专门设计的生物信息学平台鉴定含有骨髓归巢基序的相应前列腺癌细胞表面蛋白。 对于几种经验证对骨髓具有高亲和力和特异性的肽，基于它们在培养物和原位中的测试，我们建议鉴定推定的前列腺癌标志物的相应骨髓受体。 对于受体鉴定，我们将使用先前建立的候选受体的方法，传统的生物化学，和噬菌体双杂交系统的组合：最近开发的测定相互作用的蛋白质的分离。 因此，这项研究预计将确定至少一个或两个配体-受体对，这可能是建立或尚未表征的蛋白质，介导转移性前列腺癌细胞归巢到骨。 在未来，通过确定其在疾病背景下表达的选择性，可以验证所鉴定的分子作为前列腺癌分析和干预的潜在生物医学靶点。 在优化后，该方法可以被简化以系统地分析肿瘤细胞-骨髓相互作用的分子多样性，用于评估预后和/或用于治疗个体患者中的转移性前列腺癌。

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.