Analysis of Homing Receptors in Prostate Cancer

描述（由申请人提供）：前列腺肿瘤转移的特点是发生在骨中，通常导致患者预后不良。 不幸的是，没有专门针对骨转移的分子发病机制的治疗方法。 最近的研究表明，前列腺肿瘤细胞表现出增强的亲合力骨髓内皮细胞（BMEC）相比，在其他组织中的血管衬里的粘附。 我们的实验室已经表明，骨转移性前列腺肿瘤细胞和BMEC之间的初始粘附相互作用是由内皮（E）-选择素介导的。 我们已经确定了一个候选的前列腺肿瘤细胞E-选择素配体称为P-选择素糖蛋白配体-1（PSGL-1）。 值得注意的是，PSGL-1在正常前列腺上皮和局部和转移性前列腺肿瘤组织的组织微阵列（TMA）上的表达分析揭示了PSGL-1几乎仅在转移性前列腺肿瘤细胞（包括骨中的肿瘤细胞）上发现。 我们假设PSGL-1促进前列腺肿瘤转移，包括前列腺癌的骨嗜性行为。 本提案中概述的研究目的是阐明前列腺肿瘤转移的分子发病机制，并鉴定促进转移行为和/或具有靶向新型抗癌疗法的结构基序的肿瘤细胞受体。 具体目标是：1）分析E-选择素配体和PSGL-1对转移性前列腺肿瘤细胞的糖生物学调节; 2）研究E-选择素结合PSGL-1在前列腺肿瘤转移中的功能作用。 实验将包括创新的蛋白质印迹，印迹滚动和细胞粘附测定以及PSGL-1 +和-转移性前列腺肿瘤细胞的体内滚动测定。 我们将采用人骨-NOD-SCID小鼠模型来探索PSGL-1在人前列腺肿瘤进展和转移中的作用。 将分析PSGL-1 +或-人转移性前列腺肿瘤细胞归巢到人骨异种移植物中的能力。 将发展自发性前列腺腺癌和远处转移的TRAMP小鼠与PSGL-1缺失小鼠杂交，以直接测试PSGL-1在体内前列腺肿瘤进展和转移中的作用。 这些分析的结果将为前列腺肿瘤转移的分子发病机制提供新的见解，并可能为靶向归巢受体的新疗法的开发提供理论基础。

DESCRIPTION (provided by applicant): Prostate tumor metastasis characteristically occurs in bone and often results in the poor prognosis of patients. Unfortunately, there are no treatments that specifically target the molecular pathogenesis of bone metastasis. Recent studies have indicated that prostate tumor cells exhibit an enhanced avidity for bone marrow endothelium (BMEC) compared with adhesion to blood vessel linings in other tissues. Our laboratory has shown that initial adhesive interactions between bone-metastatic prostate tumor cells and BMEC is mediated by endothelial (E)-selectin. We have identified a candidate prostate tumor cell E-selectin ligand known as P-selectin glycoprotein ligand-1 (PSGL-1). Remarkably, expression analysis of PSGL-1 on tissue micro-arrays (TMA) of normal prostate epithelium and of localized and metastatic prostate tumor tissue has revealed that PSGL-1 is almost exclusively found on metastatic prostate tumor cells, including tumor cells in bone. We hypothesize that PSGL-1 facilitates prostate tumor metastasis, including the bone tropic behavior of prostate cancer. The objective of studies outlined in this proposal is to elucidate the molecular pathogenesis of prostate tumor metastasis and identify tumor cell receptors that promote metastatic behavior and/or possess structural motif(s) for targeting of novel anti-cancer therapies. The specific aims are: 1) To analyze the glycobiological regulation of E-selectin ligand and PSGL-1 on metastatic prostate tumor cells and 2) To investigate the functional role of E-selectin-binding PSGL-1 in prostate tumor metastasis. Experimentation will include innovative Western blotting, blot rolling and cell adhesion assays as well as in vivo rolling assays of PSGL-1 + and - metastatic prostate tumor cells. We will employ a hu-bone-NOD-SCID mouse model to explore the role of PSGL-1 in human prostate tumor progression and metastasis. PSGL-1 + or - human metastatic prostate tumor cells will be analyzed for their capacity to home into human bone xenografts. TRAMP mice, which develop spontaneous prostate adenocarcinoma and distant metastases, will be crossed into PSGL-1 null mice to directly test the role of PSGL-1 in prostate tumor progression and metastasis, in vivo. Results from these analyses will offer new insights into the molecular pathogenesis of prostate tumor metastasis and may provide rationale for development of new therapies targeting homing receptors.