Mechanisms of the Stromal Response to Smoothened Inhibition in Pancreatic Cancer

胰腺癌平滑抑制的基质反应机制

• 批准号: 8403907
• 负责人: Kenneth P Olive
• 金额: $ 31.4万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8403907
• 关键词: Ablation; Adrenal Glands; Adult; Affect; Alleles; Angiogenic Factor; Angiogenic Peptides; Antineoplastic Agents; Basal Cell; Basal Cell Nevus Syndrome; Basal cell carcinoma; Behavior; Binding; Biology; Cell Communication; Cell Proliferation; Cells; ChIP-seq; Clinical; Clinical Trials; Colorectal Cancer; Data; Desmoplastic; Development; Disease; Drug Delivery Systems; Ductal; Endothelial Cells; Epithelial; Epithelial Cells; Epitopes; Erinaceidae; Extracellular Matrix; Fibroblasts; Future; Gene Expression; Gene Targeting; Genes; Genetic; Genetically Engineered Mouse; Glioblastoma; Goals; Immunofluorescence Immunologic; In Vitro; Inherited; Large Intestine Carcinoma; Learning; Ligands; Lung; Maintenance; Malignant Neoplasms; Malignant neoplasm of esophagus; Malignant neoplasm of pancreas; Malignant neoplasm of prostate; Mediating; Mediator of activation protein; Mesenchymal; Mesenchyme; Molecular; Molecular Biology; Mutation; Neoplastic Epithelial Cell; Organ; Ovarian Carcinoma; Pancreatic Ductal Adenocarcinoma; Pancreatic carcinoma; Paracrine Communication; Pathway interactions; Pattern; Pharmaceutical Preparations; Play; Predisposition; Process; Reporter; Resolution; Role; Signal Transduction; Source; Stromal Cells; System; Testing; Therapeutic; Tissues; Tumor Tissue; Variant; Vascular Endothelial Growth Factors; Vascularization; Work; Wound Healing; angiogenesis; autocrine; cancer genetics; cancer type; cell type; chemotherapy; design; human SMO protein; in vivo; inhibitor/antagonist; insight; loss of function mutation; lung small cell carcinoma; malignant breast neoplasm; malignant stomach neoplasm; medulloblastoma; melanoma; mouse model; neoplastic cell; overexpression; pancreatic neoplasm; paracrine; pre-clinical; preclinical study; promoter; prostate carcinogenesis; public health relevance; research study; response; restoration; smoothened signaling pathway; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): The Hedgehog signaling pathway is overexpressed in a variety of cancers, leading to hyperactivation of target genes in Hh responding cells.1 In a number of cancers, the responding cells are stromal fibroblasts that are found near Hh ligand-expressing epithelial cells.2-5 This paracrine mechanism is one of many cell-cell interactions that take place between epithelial and mesenchymal cells. Through its role as a master regulator of other transcription factors, Hh pathway activation can have extremely potent effects on cell proliferation, behavior and survival. In pancreatic ductal adenocarcinoma (PDA), paracrine signaling from neoplastic epithelial cells to fibroblasts controls the development and maintenance of stromal desmoplasia, a very prominent feature of these tumors.4-7 We previously found that stromal desmoplasia in PDA contributes to primary chemoresistance by interfering with drug delivery.7 Inhibiting the Hh pathway with a targeted inhibitor of Smoothened (Smo) depleted the stroma from pancreatic tumors arising in a genetically engineered mouse model. This had the effect of facilitating drug delivery to the tumor parenchyma, ultimately aiding in their treatment and leading to prolonged survival. However, the precise molecular mechanisms by which Smo inhibitors target desmoplasia is unclear. To learn more about how Smo inhibitors affect stromal cells, we will examine the functional and molecular consequence of Smo inhibition in a genetically engineered mouse model of PDA. We will perform ChIP-SEQ for the downstream transcription factor Gli2 on pancreatic tumor tissues and compare the results to changes in global gene expression induced by Smo inhibition, providing insight into the differentially regulated genes whose promoters are bound by Gli transcription factors. Another effect of Smo inhibition in pancreatic tumors is the restoration of tissue vascularization, which is oddly low in pancreatic cancer. This paradoxical result is at odds with the known roles of the Hh pathway during angiogenesis. We hypothesize that angiogenesis occurs after Smo inhibition due to the relief of an anti- angiogenic signal provided by fibroblasts. We will test this by using hedgehog-independent means of depleting the stroma, and by examining several possible stroma-mediated mechanisms using tissues derived from genetically engineered mice. These experiments will leverage our expertise in mouse modeling, preclinical therapeutics and molecular biology to determine the basic mechanisms of Smo inhibition in pancreatic cancer and other systems employing paracrine Hh signaling. Currently, 25 different clinical trials have been initiated to investigate Smo inhibitors in 9 different cancers, including PDA. The experiments proposed here will aid our understanding of their results and assist in the design of future trials. More generally, we will learn about the relationship between epithelial and mesenchymal cells and the pathways that promote stromal desmoplasia in cancer.

描述（由申请人提供）：Hedgehog信号通路在多种癌症中过度表达，导致Hh应答细胞中靶基因过度激活在许多癌症中，应答细胞是在Hh配体表达上皮细胞附近发现的间质成纤维细胞。这种旁分泌机制是发生在上皮细胞和间充质细胞之间的许多细胞间相互作用之一。通过其作为其他转录因子的主调控因子，Hh通路的激活对细胞增殖、行为和存活具有极其强大的影响。在胰腺导管腺癌（PDA）中，从肿瘤上皮细胞到成纤维细胞的旁分泌信号控制着间质粘连形成的发展和维持，这是这些肿瘤的一个非常突出的特征。我们之前发现，PDA的间质结缔组织增生通过干扰药物传递而导致原发性化疗耐药在基因工程小鼠模型中，用一种靶向抑制剂Smoothened （Smo）抑制Hh通路可减少胰腺肿瘤的间质。这具有促进药物传递到肿瘤实质的作用，最终有助于治疗并延长生存期。然而，Smo抑制剂靶向结缔组织形成的确切分子机制尚不清楚。为了进一步了解Smo抑制剂如何影响基质细胞，我们将在PDA基因工程小鼠模型中研究Smo抑制的功能和分子后果。我们将对胰腺肿瘤组织下游转录因子Gli2进行ChIP-SEQ，并将结果与Smo抑制诱导的全局基因表达变化进行比较，从而深入了解Gli转录因子结合启动子的差异调控基因。Smo抑制在胰腺肿瘤中的另一个作用是恢复组织血管化，这在胰腺癌中异常低。这一矛盾的结果与Hh通路在血管生成过程中的已知作用不一致。我们假设血管生成发生在Smo抑制后，由于纤维母细胞提供的抗血管生成信号的缓解。我们将通过使用不依赖刺猬的方法来消耗基质，并通过使用来自基因工程小鼠的组织来检查几种可能的基质介导机制来验证这一点。这些实验将利用我们在小鼠建模，临床前治疗和分子生物学方面的专业知识来确定Smo抑制胰腺癌和其他使用旁分泌Hh信号的系统的基本机制。目前，25项不同的临床试验已经开始研究Smo抑制剂在9种不同癌症中的作用，包括PDA。这里提出的实验将有助于我们理解它们的结果，并有助于设计未来的试验。更一般地说，我们将了解上皮细胞和间充质细胞之间的关系以及促进癌症间质结缔组织形成的途径。