Molecular Diversity in Bladder Cancer

描述（由申请人提供）：我们开发了一种体内选择系统，其中在静脉内施用噬菌体随机肽文库后回收选择性归巢不同组织的肽。在早期的工作中，我们发现了一个以前未被识别的地址系统，该系统使器官特异性靶向和肿瘤血管生成相关靶向成为可能。靶向肿瘤的肽的相应受体是在肿瘤进展期间上调或活化的细胞表面标志物。我们还开发了用于评估器官特异性和细胞类型分布的这种探针在体内的方法。我们的工作假设是，膀胱中存在组织相关和肿瘤分期相关的异质性;这种多样性可能影响对治疗的反应。在这里，我们建议定义（i）正常尿路上皮和（ii）膀胱癌中存在的细胞和分子差异。在具体目标#1下，我们将探索基于体内和离体噬菌体展示结合激光捕获显微切割（LCM）技术的新策略。我们的目标是分离肽，在体内的家到小鼠膀胱或结合离体的各种膀胱细胞类型。在特定目标#2下，我们将分离在肿瘤进展的不同阶段（从早期到晚期转移性疾病）归巢膀胱的肽和抗体。在互补策略中，我们将选择在膀胱癌进展的选定阶段被免疫球蛋白的循环池识别的肽。这些特异性探针将用于鉴定新的肿瘤和肿瘤相关抗原。在具体目标#3下，我们将分离、克隆和评估这些特异性和肿瘤特异性标志物在膀胱癌进展背景下的表达模式和功能。新的膀胱和膀胱癌受体的鉴定可能揭示了膀胱复杂的细胞和分子多样性。在特定目标#4下，我们将鉴定具有内化到尿路上皮细胞中的能力的特定肽。紧密细胞连接、携带糖胺聚糖（GAG）的特化管腔细胞表面和粘蛋白层的组合保护哺乳动物尿路上皮免受浓缩尿液化学物质和微生物粘附的影响。然而，在病理条件下，尿道炎的这些特征成为治疗剂有效递送至膀胱的障碍。在此，我们提出了追求候选肽的能力内化到尿路上皮细胞开发治疗膀胱癌的治疗靶向策略。

DESCRIPTION (provided by applicant): We have developed an in vivo selection system in which peptides that home selectively to different tissues are recovered after intravenous administration of a phage random peptide library. In earlier work, we uncovered a previously unrecognized address system that makes possible organ-specific targeting and angiogenesis-related targeting of tumors. The corresponding receptors for the peptides targeting tumors are cell surface markers that are upregulated or activated during tumor progression. We also developed methods for assessing organ-specificity and cell-type distribution of such probes in vivo. Our working hypothesis is that there are tissue-related and tumor stage related heterogeneity in the bladder; such diversity may affect the responses to therapies. Here, we propose to define the cellular and molecular differences that exist (i) in normal urothelium and (ii) in bladder cancer. Under Specific Aim #1, we will explore novel strategies based on in vivo and ex-vivo phage display combined with Laser Capture Microdissection (LCM) technologies. We aim to isolate peptides that home in vivo to the mouse bladder or that bind ex vivo to various bladder cell types. Under Specific Aim #2, we will isolate peptides and antibodies that home to the bladder at different stages of tumor progression, from early to late metastatic disease. In a complementary strategy, we will select peptides that are recognized by the circulating pool of immunoglobulins at selected stages of bladder cancer progression. These specific probes will be used to identify new tumor- and tumor-associated antigens. Under Specific Aim #3, we will isolate, clone, and evaluate the expression pattern and function of these specific and tumor-specific markers in the context of bladder cancer progression. The identification of novel bladder and bladder cancer receptors may shed light in the complex cellular and molecular diversity of the bladder. Under Specific Aim #4, we will identify specific peptides that have the ability to internalize into urothelial cells. The combination of tight cell junctions, a specialized luminal cell surface bearing glycosaminoglycans (GAG), and a mucin layer protect the mammalian urothelium against concentrated urine chemicals and microbial adhesion. However, under pathological conditions, such features of the urothelium become obstacles to effective delivery of therapeutic agents to the bladder. Herein we propose to pursue candidate peptides with the ability to internalize into urothelial cells to develop therapeutic targeting strategies for the treatment of bladder cancer.