Alternatively Spliced Tissue Factor and Pathobiology of Pancreatic Cancer

描述（由申请人提供）：我们建议评估最近发现的称为选择性剪接组织因子（asTF）的蛋白质是否可以导致开发新的策略来对抗胰腺癌，特别是胰腺导管腺癌（PDAC），这是一种高度致命的癌症形式，也是一个主要的治疗挑战。asTF表达在PDAC中增加，并且其增强单核细胞募集、PDAC细胞增殖和迁移、耐缺氧、转移扩散和血管生长。我们证实asTF作为一种非蛋白水解的细胞激动剂，在肿瘤间质中增加PDAC的生长和扩散。为了研究asTF在PDAC中的作用模式，并评估其作为靶点的潜在效用，我们提出了以下三个目的：1。要识别的域，请执行以下操作： 结合β 1整联蛋白并通过β 1整联蛋白进行信号传导所需的人asTF。asTF在非典型区域结合β 1整联蛋白，作为整联蛋白配体/激活剂。我们将通过产生重组asTF突变体，体外评估所产生的表型，然后在PDAC细胞中表达它们，以确认我们的体内发现，来绘制通过β 1整联蛋白进行信号传导所需的asTF结构域。2.确定肿瘤源性asTF与宿主源性asTF对PDAC进展的贡献。该目的的基本原理基于肿瘤细胞以及基质单核细胞表达的asTF促进PDAC细胞增殖、单核细胞募集和已建立的转移瘤的侵袭性生长的假设。我们将使用一套独特的工具（细胞系、转基因小鼠和创新的成像技术）来评估 肿瘤细胞来源的asTF和宿主细胞来源的asTF对PDAC进展的相对贡献。3.目的探讨抗asTF单克隆抗体Rb 1治疗PDAC的可能性。我们建立了在裸鼠中生长人PDAC肿瘤标本的程序，并开发了抑制性抗人asTF单克隆抗体Rb 1，其在体外减少PDAC细胞的迁移，并在体内抑制PDAC细胞生长。我们将评估全身给予Rb 1减少人PDAC细胞和患者来源的PDAC肿瘤异种移植物生长的能力，以及Rb 1诱导免疫细胞和补体介导的细胞毒性的潜力。完成后，我们的研究极有可能i）对asTF在PDAC进展中的作用产生新的见解，这可能为治疗PDAC开辟新的途径，ii）阐明β 1整联蛋白信号传导在PDAC发病机制中的意义，iii）提高对单核细胞/巨噬细胞在PDAC病理生物学中所起作用的理解。

DESCRIPTION (provided by applicant): We propose to evaluate whether a recently discovered protein termed alternatively spliced Tissue Factor (asTF) can lead to the development of new strategies to fight pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), a highly lethal form of cancer and a major therapeutic challenge. asTF expression is increased in PDAC and it enhances monocyte recruitment, PDAC cell proliferation and migration, resistance to hypoxia, metastatic spread, and vessel growth. We posit that asTF enhances PDAC growth and spread as it accrues in tumor stroma, acting as a non-proteolytic cell agonist. To study asTF's mode(s) of action in PDAC and evaluate its potential utility as a target, we propose the following three Aims: 1. To identify the domain(s) of human asTF required for binding to, and signaling via beta1 integrins. asTF binds beta1 integrins in a non-canonical region, acting as an integrin ligand/activator. We will map asTF domain(s) required to signal via beta1 integrins by generating recombinant asTF mutants, assessing the resultant phenotype(s) in vitro, and then expressing them in PDAC cells to confirm our findings in vivo. 2. To determine the contribution of tumor-derived versus host- derived asTF to PDAC progression. Rationale for this Aim is grounded in the hypothesis that asTF expressed by tumor cells as well as stromal monocytes fuels PDAC cell proliferation, monocyte recruitment, and aggressive growth of established metastases. We will use a unique set of tools (cell lines, genetically modified mice, and innovative imaging technologies) to assess the relative contribution of tumor cell-derived asTF, and host cell-derived asTF to PDAC progression. 3. To investigate the potential utility of the inhibitory anti-asTF monoclonal antibod Rb1 to treat PDAC. We established the procedure for growing human PDAC tumor specimens in nude mice, and developed an inhibitory anti-human asTF monoclonal antibody Rb1 that reduces migration of PDAC cells in vitro, and suppresses PDAC cell growth in vivo. We will assess the ability of systemically administered Rb1 to reduce the growth of human PDAC cells and patient-derived PDAC tumor xenografts, and Rb1's potential to induce immune cell- and complement-mediated cytotoxicity. Upon completion, our studies are highly likely to i) yield new insights into the role of asTF in PDAC progression, which may open new avenues to treat PDAC, ii) elucidate the significance of beta1 integrin signaling in PDAC pathogenesis, and iii) improve understanding of the role(s) played by monocytes/macrophages in PDAC pathobiology.