Thrombin-dependent mechanisms of pancreatic ductal adenocarcinoma disease

项目摘要 胰腺导管腺癌（PDAC）是所有癌症中死亡率最高的，正在迅速成为 是美国癌症死亡的第二大原因，据估计，医疗保健系统将花费2.4美元， 每年10亿。PDAC患者的5年生存率为7%， 患有转移性疾病的个体。不幸的是，在改变患者结果方面几乎没有进展， 在过去的40年里，强调需要创新的方法来定义分子途径， 影响PDAC的发展。PDAC可以在获得激活的外分泌上皮细胞中启动 KRAS原癌基因突变，导致细胞转化为胰腺上皮内瘤变 （PanIN）病变可进展为PDAC。对KRAS活性的关键转录反应增加 表达凝血系统的生理激活剂组织因子（TF）。TF介导 凝血酶原转化为活性蛋白酶凝血酶，这反过来又促进了纤维蛋白在 肿瘤微环境（TME）和激活G蛋白偶联蛋白酶激活受体（PAR） 靶细胞，包括PDAC肿瘤细胞、肿瘤相关巨噬细胞（TAM）和癌症相关巨噬细胞。 成纤维细胞（CAF）。科学的前提是基于胰腺癌和胰腺癌之间的已知关系。 高水平的血液凝固系统活性，但其独特之处在于它将定义新发现的 TME中的特异性凝血因子通过其促进PDAC发病机制的串扰。我们的中央 假设凝血酶驱动早期PanIN发展以及晚期PDAC肿瘤生长， 通过与TME中的纤维蛋白基质沉积和肿瘤上的PAR-1信号传导相关的机制转移 和TME细胞促进PDAC疾病的前馈途径。这一假设将通过使用 独特的基因工程小鼠模型，尖端的药物试剂， 患者来源的PDAC肿瘤细胞追求三个特定的目的-（1）确定凝血酶-纤维蛋白轴 有助于早期PanIN发展和晚期PDAC肿瘤生长和转移;（2）确定 肿瘤细胞、TAM和CAF上凝血酶受体PAR-1信号传导的个体机制 加重PDAC发病机制的不同方面;和（3）确定药理学纤维蛋白 和PAR-1抑制在阻止已建立的小鼠PDAC和人患者来源的PDAC进展中的作用。 异种移植瘤这些研究意义重大，因为它们将（i）首次确定 凝血酶在整个PDAC疾病;（ii）确定凝血酶依赖性PDAC疾病的具体机制 进展;和（iii）提供使用特定的最先进的抑制剂靶向PDAC肿瘤的新机会 纤维蛋白基质和PAR-1信号通路。这些发现将极大地促进对 PDAC疾病的潜在机制，并有望突出新的治疗机会， 开发更好的治疗方案-这是一个长期目标，对患者的结局有最大的益处。

PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDAC) has the highest mortality rate of all cancers, is rapidly becoming the second leading cause of cancer deaths in the U.S., and is estimated to cost the health care system $2.4 billion each year. Patients with PDAC have a 5-year survival rate of 7% and that number drops to 2% for individuals with metastatic disease. Unfortunately, there has been little progress in shifting patient outcome over the past 40 years, highlighting the need for innovative approaches to define the molecular pathways that influence PDAC development. PDAC can be initiated in exocrine epithelial cells that acquire an activating mutation in the KRAS protooncogene, causing the cells to transition to pancreatic intraepithelial neoplasia (PanIN) lesions that can progress into PDAC. A key transcriptional response to KRAS activity is increased expression of the physiological activator of the coagulation system, Tissue Factor (TF). TF mediates conversion of prothrombin to the active protease thrombin that in turn promotes extensive fibrin deposits within the tumor microenvironment (TME) and activates G-protein coupled protease-activated receptors (PARs) on target cells, including PDAC tumor cells, tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs). The scientific premise is based on a known relationship between pancreatic cancer and high-level blood coagulation system activity, but is unique in that it will define newly discovered mechanisms of crosstalk by which specific coagulation factors in the TME promote PDAC pathogenesis. Our central hypothesis is that thrombin drives early PanIN development as well as advanced PDAC tumor growth and metastasis by mechanisms linked to both fibrin matrix deposition in the TME and PAR-1 signaling on tumor and TME cells promoting a feed forward pathway of PDAC disease. This hypothesis will be tested by utilizing a combination of unique genetically engineered mouse models, cutting-edge pharmaceutical reagents, and patient-derived PDAC tumor cells to pursue three Specific Aims - (1) determine how the thrombin-fibrin axis contributes to early PanIN development and late stage PDAC tumor growth and metastasis; (2) determine the individual mechanisms by which thrombin receptor PAR-1 signaling on tumor cells, TAMs and CAFs exacerbates distinct aspects of PDAC pathogenesis; and (3) determine the efficacy of pharmacological fibrin and PAR-1 inhibition in halting the progression of established mouse PDAC and human patient-derived xenograft tumors. These studies are significant because they will (i) be the first to define the impact of thrombin throughout PDAC disease; (ii) identify specific mechanisms of thrombin-dependent PDAC disease progression; and (iii) provide novel opportunities to target PDAC tumors using specific state-of-the-art inhibitors of fibrin matrix and PAR-1 signaling pathways. The discoveries made will greatly advance the understanding of mechanisms underlying PDAC disease and are expected to highlight novel therapeutic opportunities for developing improved treatment options - a long-term goal with the greatest benefit to patient outcome.