Targeting stem-like cells and their niche in pancreatic cancer

项目总结 胰腺导管腺癌(PDAC)患者确诊后存活5年的比例不到8%。PDAC是 通常在晚期确诊，限制了治疗选择。化疗是广告的中流砥柱。 先进的PDAC，尽管它们会产生不完整的响应。因此，开发治疗PDAC的新疗法 迫切需要病人。PDAC标准化疗失败的一个可能原因是细胞 肿瘤内表型的异质性。异质性可能使细胞亚群在治疗中存活 并重新填充肿瘤。肿瘤干细胞(CSCs)存在于多种实体肿瘤中。 CSCs具有强大的增殖能力，通常对癌症治疗具有抵抗力。淘汰或重新区分- 肿瘤干细胞的鉴定是一种有吸引力的策略：通过将肿瘤细胞表型均质化在组织工程中。 更重要的是，这种疗法可能会抑制肿瘤的进展，并导致对传统热疗的改善反应。 派。我们的试验数据表明，由一个癌细胞亚群产生的分泌的Wnt配体驱动干细胞- 在另一个癌细胞亚群中类似的状态，本质上形成了一个专门的微环境，或利基， 在维持肿瘤干细胞的胰腺肿瘤内。我们发现CSCs表达Wnt靶基因Lgr5，而 利基细胞被豪猪碱标记，这是一种翻译后修饰Wnt的酶。假设：颠覆性 CSC和NICE细胞可以转化为PDAC患者的新治疗策略。我们建议确定 Lgr5+CSC和豪猪+龛细胞状态的驱动机制以及Wnt抑制的可能性。 TORS在PDAC治疗中的应用。这些研究有可能转化为新的PDAC疗法。目标1.内部- Lgr5+干细胞样PDAC细胞的门功能。我们将分析Lgr5+胰腺癌细胞并评估其能力 在功能上促进PDAC的进展、转移和对化疗的耐药性。我们将表演 基因工程中Lgr5+细胞的谱系追踪和消融、基因表达和蛋白质组学研究 嵌合的小鼠PDAC肿瘤。结果将确定Lgr5+细胞是否为已建立的肿瘤和 告知它们的分子特征，这可能提供更多的手段来靶向这些细胞。目标2.澄清 豪猪+PDAC壁龛细胞的生物学研究我们将确定推动豪猪+生态位的分子机制 单元状态。我们将使用豪猪报告等位基因来去除PDAC中的这些细胞，以评估其在肿瘤进展中的作用。 Sion，并分离利基细胞以进行蛋白质组和基因表达谱分析。结果将提供对角色的洞察 豪猪+细胞在PDAC进展中的作用以及如何靶向它们。目的3.治疗靶向Wnt信号转导 在PDAC中。我们将通过使用豪猪的小分子抑制剂作为单一药物和在 与化疗相结合。为了改善这些药物对促结缔组织增生性PDAC肿瘤的输送，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动物身上进行测试。 RNF43野生型和突变型PDAC异种移植模型的建立这些努力将考验Thera- 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.