Exploitation of RAS signaling to develop therapy and early detection strategies for PDA

利用 RAS 信号传导开发 PDA 的治疗和早期检测策略

• 批准号: 9012030
• 负责人: Rolf A Brekken
• 金额: $ 43.59万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-10 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9012030
• 关键词: 1-Phosphatidylinositol 3-Kinase; Abraxane; Acinar Cell; Address; Adult; Apoptosis; Biological; Biological Assay; Blood; Cancer Biology; Carcinoma; Cell Proliferation; Cells; Chronic; DDR1 gene; DDR2 gene; DNA; Development; Disease; Drug Combinations; Drug resistance; Duct (organ) structure; Ductal; Ductal Epithelial Cell; Early Diagnosis; Early identification; Endocrine; Epithelial; Event; Feedback; G Protein-Coupled Receptor Signaling; G alpha q Protein; Gene Expression; Gene Fusion; Genetic; Goals; Growth; Health; Intraepithelial Neoplasia; Ligands; Maintenance; Malignant Neoplasms; Malignant neoplasm of pancreas; Mass Spectrum Analysis; Metabolic; Metaplasia; Modeling; Monitor; Mouse Cell Line; Mucinous Neoplasm; Mus; Neoplasm Metastasis; Neoplasms; Oncogenes; Oncogenic; Pancreas; Pancreatic Ductal Adenocarcinoma; Pancreatic Intraepithelial Neoplasia; Pancreatic duct; Pancreatitis; Papillary; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Physiology; Plasma; Point Mutation; Process; Proteinase 3; Proteomics; Public Health; RGS Family Gene; RGS Proteins; Ras Inhibitor; Receptor Protein-Tyrosine Kinases; Refractory; Regulation; Reporter; Reporter Genes; Research; Signal Pathway; Signal Transduction; Staging; Stem cells; Stress; System; Techniques; Testing; Therapeutic; Transcriptional Regulation; Tumor Burden; Tumor Suppressor Proteins; Warfarin; Xenograft procedure; actionable mutation; axl receptor tyrosine kinase; base; cell type; chemotherapy; connective tissue growth factor; drug development; effective therapy; exome sequencing; experience; fusion gene; gemcitabine; gene induction; improved; in vivo; in vivo Model; inhibitor/antagonist; innovation; insight; migration; mimetics; mouse model; mutant; neoplastic cell; novel; novel drug combination; novel marker; novel therapeutics; pancreas development; pancreatic neoplasm; progenitor; pup; response; screening; small molecule; standard of care; therapy development; tool; transcription factor; transcriptome sequencing; tumor; tumor growth; tumor initiation; tumor microenvironment; tumor progression

DESCRIPTION (provided by applicant): The therapeutic problem we address is how to inhibit the development and progression of IPMN (intraductal papillary mucinous neoplasm), PanIN (Pancreatic Intraepithelial Neoplasia) and PDA (pancreatic ductal adenocarcinoma). The biological problem is to identify key signaling pathways that initiate and propagate IPMN, PanIN and PDA. A central debate in the field is whether PDA initiates in pancreatic progenitor cells or with dedifferentiation of parenchymal acinar cells to progenitor-like ductal cells, in a process termed acinar to ductal metaplasia (ADM). The function of the transcription factor Master Regulators (MRs) of acinar cell identity is critical to this process but post-translational regulaton of their activity through receptor tyrosine kinase (RTK) and G protein coupled receptor (GPCR) signaling is completely unexplored. Regulators of G protein signaling (RGS) proteins integrate multiple intracellular signals from RTKs and GPCRs to feedback regulate Gi and Gq protein signaling. We have developed a GFP reporter (Rgs16:GFP) that allows us to monitor neoplasia and tumor formation from early stages in in vivo mouse models of IPMN, PanIN and PDA. Combining the Rgs16:GFP reporter with mouse models for IPMN, PanIN and PDA is providing insights into development of these tumors and a novel and rapid in vivo screen for inhibitors of this process. We discovered RGS genes that suppress progression of IPMN to invasive carcinoma. Based on preliminary analyses using these models, we find that IPMN and PanIN initiate in discrete ductal progenitor cells in response to stress in the acinar or endocrine compartments of the pancreas. This interpretation challenges the currently favored paradigm that PDA initiates with cells that underwent ADM whereas we propose that chronic ADM stimulates proliferation of pre-existing progenitor cells in ducts. We find that the RTK Axl is expressed in pancreatic ducts and is highly expressed with Rgs16:GFP in PDA progenitor cells in primary culture. Our hypothesis is that the Axl-ligand Gas6 expressed in stroma evokes Axl signaling in epithelial progenitor cells and contributes to activation of KrasG12D, post-translational control of MR levels and/or activity, PDA initiation and progression. In our preliminary in vivo screens of new therapeutics to inhibit PDA progression, we determined that warfarin, which blocks Gas6 induced activation of Axl, combined with the standard of care Gemcitabine and Abraxane (GA), significantly reduced PDA progression. The Specific Aims of this proposal are 1) Identify optimal drug combinations, including inhibitors of Axl signaling, to inhibit PDA. 2) Identify early markers of IPMN, PanIN and PDA in plasma. 3) Determine Gas6-Axl function in PDA. The proposed project, if successful, will have a major impact on cancer by i) identifying early blood markers of PDA, and perhaps other epithelial cancers, ii) introducing a novel, general and rapid in vivo screening technique to find novel drug combinations that inhibit PDA progression, iii) providing novel genetic tools to determine if PDA initiates in progenitor cells in the pancreatic duct, Iv) identify previously unknown regulatory mechanisms of the MR transcription factors.

描述（申请人提供）：我们解决的治疗问题是如何抑制IPMN（导管内乳头状粘液性肿瘤）、PanIN（胰腺上皮内瘤变）和PDA（胰腺导管腺癌）的发生和进展。生物学问题是确定启动和传播 IPMN、PanIN 和 PDA 的关键信号通路。该领域的一个中心争论是，PDA 是在胰腺祖细胞中起始，还是在实质腺泡细胞去分化为祖细胞样导管细胞时起始，这个过程被称为腺泡到导管化生 (ADM)。腺泡细胞身份的转录因子主调节器 (MR) 的功能对此过程至关重要，但通过受体酪氨酸激酶 (RTK) 和 G 蛋白偶联受体 (GPCR) 信号传导对其活性进行翻译后调节尚未完全探索。 G 蛋白信号传导 (RGS) 蛋白的调节剂整合来自 RTK 和 GPCR 的多个细胞内信号，以反馈调节 Gi 和 Gq 蛋白信号传导。我们开发了 GFP 报告基因 (Rgs16:GFP)，使我们能够在 IPMN、PanIN 和 PDA 体内小鼠模型的早期阶段监测肿瘤形成和肿瘤形成。将 Rgs16:GFP 报告基因与 IPMN、PanIN 和 PDA 小鼠模型相结合，可以深入了解这些肿瘤的发展，并为该过程的抑制剂提供新颖且快速的体内筛选。我们发现 RGS 基因可以抑制 IPMN 进展为浸润性癌。基于使用这些模型的初步分析，我们发现 IPMN 和 PanIN 在离散的导管祖细胞中启动，以响应胰腺腺泡或内分泌室的应激。这种解释挑战了目前流行的模式，即 PDA 从接受 ADM 的细胞开始，而我们认为慢性 ADM 会刺激导管中预先存在的祖细胞的增殖。我们发现RTK Axl在胰管中表达，并且在原代培养的PDA祖细胞中与Rgs16:GFP一起高表达。我们的假设是，基质中表达的 Axl-配体 Gas6 会引发上皮祖细胞中的 Axl 信号传导，并有助于 KrasG12D 的激活、MR 水平和/或活性的翻译后控制、PDA 的启动和进展。在抑制 PDA 进展的新疗法的初步体内筛选中，我们确定华法林（可阻断 Gas6 诱导的 Axl 激活）与标准护理吉西他滨和 Abraxane (GA) 相结合，可显着减缓 PDA 进展。该提案的具体目标是 1) 确定最佳药物组合，包括 Axl 信号传导抑制剂，以抑制 PDA。 2) 鉴定血浆中IPMN、PanIN和PDA的早期标志物。 3)确定PDA中Gas6-Axl的功能。拟议的项目如果成功，将对癌症产生重大影响，方法是：i) 识别 PDA 的早期血液标志物，或许还有其他上皮癌，ii) 引入一种新颖、通用和快速的体内筛选技术，以寻找抑制癌症的新型药物组合。 PDA 进展，iii) 提供新的遗传工具来确定 PDA 是否在胰管的祖细胞中起始，iv) 识别以前未知的 MR 转录因子的调节机制。