Targeting stem-like cells and their niche in pancreatic cancer

项目摘要 不到8%的胰腺导管腺癌（PDAC）患者在诊断后存活5年。PDAC是 通常在晚期诊断，限制了治疗选择。化疗是AD的主要治疗手段- 先进的PDAC，虽然他们产生不完整的反应。因此，PDAC的新疗法的开发 患者急需。PDAC标准化疗失败的可能解释是细胞 肿瘤内的表型异质性。异源性可以使细胞亚群在治疗中存活 并重新填充肿瘤癌症干细胞样细胞（CSC）已经在多种实体瘤类型中描述。 CSC具有强大的增殖潜力，并且通常对癌症疗法具有抗性。删除或重新区分- 癌症干细胞样细胞的诱导是一种有吸引力的策略：通过在肿瘤细胞中检测癌细胞表型， 此外，这种疗法可以抑制肿瘤进展，并改善对常规疗法的反应。 派我们的试验数据表明，由一个癌细胞亚群产生的分泌型Wnt配体驱动干细胞， 类似于另一个癌细胞亚群中的状态，本质上形成一个专门的微环境，或生态位， 在胰腺肿瘤中维持CSC。我们发现CSC表达Wnt靶基因Lgr 5，而 小生境细胞以豪猪蛋白（Porcupine）为标记，豪猪蛋白是一种在免疫后修饰Wnt的酶。假设：破坏 CSC和小生境细胞可以转化为PDAC患者的新治疗策略。我们建议确定 驱动Lgr 5 + CSC和Porcupine+ niche细胞状态的机制，并探索Wnt抑制的潜力。 PDAC治疗的方法这些研究有可能转化为新的PDAC疗法。目标1.间- Lgr 5+干细胞样PDAC细胞的门控功能。我们将分析Lgr 5+胰腺癌细胞并评估其能力， 在功能上有助于PDAC进展、转移和对化疗的抗性。我们将执行 在基因工程中，Lgr 5+细胞的谱系追踪和消融，基因表达和蛋白质组学分析， 小鼠PDAC肿瘤。结果将确定Lgr 5+细胞是否是已建立的肿瘤中的CSC， 告知它们的分子特征，这可以提供额外的手段来靶向这些细胞。目标2.阐明 豪猪+ PDAC生态位细胞的生物学。我们将确定驱动豪猪+生态位的分子机制 细胞状态。我们将使用Porcupine报告等位基因在PDAC中消融这些细胞，以评估在肿瘤进展中的作用。 锡永小生境细胞用于蛋白质组学和基因表达谱分析。结果将提供有关角色的见解 豪猪+细胞在PDAC进展中的作用以及如何靶向它们。目标3。治疗性靶向Wnt信号传导 在PDAC。我们将通过使用豪猪的小分子抑制剂作为单一药物靶向Wnt信号传导， 联合化疗。为了改善这些药物在促结缔组织增生性PDAC肿瘤中的递送，我们将 将它们与环糊精载体分子复合。这些疗法将在原位小鼠和大鼠中进行测试。 RNF 43野生型和突变型PDAC中PDAC的细胞来源的异种移植模型。这些努力将检验治疗- Wnt抑制剂在PDAC中的潜在作用可能使胰腺肿瘤对化疗敏感。

PROJECT SUMMARY Less than 8% of pancreatic ductal adenocarcinoma (PDAC) patients are alive 5 years after diagnosis. PDAC is typically diagnosed at an advanced stage, limiting treatment options. Chemotherapies are the mainstay for ad- vanced PDAC, though they produce incomplete responses. Thus, development of novel therapies for PDAC patients is urgently needed. A possible explanation for failure of standard chemotherapies in PDAC is cellular phenotypic heterogeneity within tumors. Heterogeneity may enable subpopulations of cells to survive therapy and repopulate the tumor. Cancer stem-like cells (CSCs) have been described in multiple solid tumor types. CSCs have robust proliferative potential and are typically resistant to cancer therapies. Elimination or re-differ- entiation of cancer stem-like cells is an attractive strategy: By homogenizing cancer cell phenotypes within tu- mors, such therapies may suppress tumor progression and lead to improved responses to conventional thera- pies. Our pilot data suggest that secreted Wnt ligands produced by one cancer cell subpopulation drive a stem- like state in another cancer cell subpopulation, in essence forming a specialized microenvironment, or niche, within pancreatic tumors that maintains CSCs. We found that CSCs express Wnt target gene Lgr5, whereas niche cells are marked by Porcupine, an enzyme that post-translationally modifies Wnt. Hypothesis: Disrupting CSC and niche cells can translate into novel therapeutic strategies for PDAC patients. We propose to identify mechanisms that drive Lgr5+ CSC and Porcupine+ niche cell states and to explore the potential of Wnt inhibi- tors in PDAC therapy. These studies have the potential to translate into new PDAC therapies. Aim 1. Interro- gate function of Lgr5+ stem-like PDAC cells. We will profile Lgr5+ pancreatic cancer cells and evaluate ability to functionally contribute to PDAC progression, metastasis, and resistance to chemotherapy. We will perform lineage-tracing and -ablation, and gene expression and proteomic profiling of Lgr5+ cells in genetically engi- neered mouse PDAC tumors. Results will determine whether Lgr5+ cells are CSCs in established tumors and inform their molecular characteristics, which may provide added means to target these cells. Aim 2. Elucidate biology of Porcupine+ PDAC niche cells. We will identify molecular mechanisms that drive Porcupine+ niche cell state. We will use Porcupine reporter allele to ablate these cells in PDAC to evaluate role in tumor progres- sion, and isolate niche cells for proteomic and gene expression profiling. Results will provide insights into role of Porcupine+ cells in PDAC progression and how to target them. Aim 3. Therapeutically target Wnt signaling in PDAC. We will target Wnt signaling by using small molecule inhibitors of Porcupine as single agents and in combination with chemotherapy. To improve delivery of these drugs into desmoplastic PDAC tumors, we will complex them with cyclodextrin carrier molecules. These therapies will be tested in orthotopic mouse and pa- tient-derived xenograft models of PDAC in RNF43 wild-type and mutant PDAC. These efforts will test thera- peutic potential of Wnt inhibitors in PDAC, which may sensitize pancreatic tumors to chemotherapy.