Cancer-associated fibroblast in the regulation of bladder cancer stem cells

描述（由申请人提供）：膀胱癌是美国第五大最常见的恶性肿瘤，每年约有70,000例新诊断病例，在开始进展后基本上是无法治愈的。许多困难在于缺乏对纤维母细胞微环境功能参与的机制认识，以及它与上皮癌室在调节早期膀胱癌侵袭中的相互作用。申请人和他的合作者在缩小这一差距方面取得了相当大的进步。他们是第一批分离和鉴定人类膀胱癌干细胞的人。最近，他们发现表型癌干细胞的扩增与较差的临床结果和膀胱癌侵袭相关。他们的建议旨在通过阐明癌症相关成纤维细胞（CAFs）在膀胱癌干细胞和肿瘤进展调节中的功能贡献来扩展这些发现。这一应用的基础是证明CAF基因表达升高的膀胱癌患者也患有肌肉浸润性癌症，生存率较低。此外，活化的CAFs位于表型癌症干细胞附近，这表明这两种细胞类型之间可能存在功能相互作用。其他研究结果表明，cas分泌的胶原I （COL1）可以结合盘状蛋白结构域受体酪氨酸激酶1 （DDR1）对膀胱癌细胞起重要作用，并调节其致瘤特性。这一进展导致了一个新的工作假设——激活的CAFs和膀胱癌细胞之间的COL1-DDR1信号是CAFs调节癌症干细胞和肿瘤进展的机制之一。将追求三个具体的研究目标。目的1旨在确定CAFs在调节癌症干细胞和肿瘤进展中的功能参与，重点是使用原发性患者标本。为了进一步明确CAFs的临床意义，我们将利用两个独立的患者队列来评估CAFs/COL1表达与膀胱癌分化和选定的临床预后信息的关系。Aim 2将采用功能获得和功能丧失策略来确定DDR1对膀胱癌细胞的功能贡献，以介导CAFs促进的生物学特性。这些研究将得到新分离的膀胱CAFs的可用性和申请人在分离癌症干细胞以供后续分析方面的专业知识的帮助。最后，Aim 3将使用已建立的蛋白质组学分析方法访问Stat3和与DDR1相关的其他下游机制。申请人打算在该途径中发现早期膀胱癌干预的药物靶点，作为本提案的长期目标。

DESCRIPTION (provided by applicant): Bladder cancer, the fifth most common malignancy in the U.S. with approximately 70,000 new cases diagnosed each year, is essentially incurable after it has begun to progress. Much of the difficulty lies in the scarcity of mechanistic insightsin the functional involvement of the fibroblastic microenvironment, and its interactions with the epithelial cancer compartment in modulating early bladder cancer invasion. The applicant and his collaborators have made considerable strides in closing this gap. They were among the first to isolate and characterize human bladder cancer stem cells. Recently, they showed that an expansion of phenotypic cancer stem cells correlates with a poorer clinical outcome and bladder cancer invasion. Their proposal aims to extend these findings by elucidating the functional contribution of cancer-associated fibroblasts (CAFs) in the modulation of bladder cancer stem cells and tumor progression. This application has its foundation via demonstrating that bladder cancer patients with an elevated expression of CAF genes also have muscle-invasive cancer and a poorer survival. Moreover, activated CAFs localize immediately adjacent to phenotypic cancer stem cells, suggesting a possible functional interaction between these two cell types. Additional findings indicate an important role of collagen I (COL1) excreted by CAFs, which can bind to discoidin domain receptor tyrosine kinase 1 (DDR1) on bladder cancer cells and modulate their tumorigenic properties. This progress has led to a novel working hypothesis - that COL1-DDR1 signaling between activated CAFs and bladder cancer cells is one of the mechanisms exerted by CAFs to regulate cancer stem cells and tumor progression. Three specific research aims will be pursued. Aim 1 seeks to establish the functional involvement of CAFs in the regulation of cancer stem cells and tumor progression, with an emphasis on using primary patient specimens. To further define the clinical significance of CAFs, we will utilize tw independent patient cohorts to assess the expression of CAFs/COL1 in relation to bladder cancer differentiation and selected clinical prognostic information. Aim 2 will employ both gain-of-function and loss-of-function strategies to define the functional contributions of DDR1 on bladder cancer cells to mediate the biological properties promoted by CAFs. These studies will be aided by the availability of newly isolated bladder CAFs and the applicant's expertise in isolating cancer stem cells for subsequent analysis. Finally, Aim 3 will access Stat3 and additional downstream mechanisms related to DDR1, using established proteomics profiling approach. The applicant intends to uncover druggable targets within this pathway for early bladder cancer intervention, as the long-term goal of this proposal.