Regulation and Function of Stromal Macropinocytosis in Pancreatic Ductal Adenocarcinoma

胰管腺癌间质巨胞饮的调控和功能

基本信息

批准号：
10293358
负责人：
Cosimo Commisso
金额：
$ 58.09万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10293358
关键词：
Actins Amino Acids Automobile Driving Bioenergetics Biological Bypass Cancer Etiology Cancer Patient Cell physiology Cells Cessation of life Cytoskeleton Data Development Evaluation Extracellular Protein Fibroblasts Glucose Glutamine Immune Immune checkpoint inhibitor In Vitro Link Liquid substance Malignant Neoplasms Malignant neoplasm of pancreas Metabolic Metabolism Modality Molecular Nutrient Pancreatic Ductal Adenocarcinoma Pathway interactions Patients Pharmacology Phase Phenotype Play Process Property Proteins Publishing Regulation Research Role Route Signal Transduction Source Starvation Strategic Planning Stress Stromal Cells Supporting Cell Testing Therapeutic Time United States Work base cancer cell cell stroma cell type chemotherapy deprivation extracellular fitness in vivo mouse model neoplastic cell novel novel therapeutics pancreatic ductal adenocarcinoma cell pancreatic ductal adenocarcinoma model sensor tumor tumor growth tumor microenvironment uptake

项目摘要

PROJECT SUMMARY Recent years have witnessed an appreciation of the role that metabolic adaptation plays in conferring survival advantages to cells that encounter the harsh nutrient-poor conditions of the tumor microenvironment. Of particular relevance to this proposal is the now widely accepted notion that macropinocytosis, an endocytic mechanism of fluid-phase uptake, functions in tumors as an amino acid supply route. By stimulating the uptake of extracellular protein and targeting it for lysosomal degradation, macropinocytosis provides cells with a source of protein-derived amino acids, allowing tumors to circumvent amino acid depletion and survive nutrient stress. Pancreatic ductal adenocarcinoma (PDAC) tumors are deficient in glutamine, a vital nutrient that supports tumor growth. Our published work in PDAC cells has established that glutamine depletion has the capacity to modulate macropinocytosis – dialing the process up or down as required. Interestingly, our preliminary data presented in this proposal demonstrate for the first time that glutamine scarcity can also stimulate macropinocytosis in cancer-associated fibroblasts (CAFs). Mechanistically, we have attributed glutamine stress-induced macropinocytic uptake in CAFs to a CAMKK2-AMPK signal that leads to the Rac1- dependent actin cytoskeleton dynamics that are required for macropinocytosis. AMPK is a bioenergetic stress sensor that is most often studied in the context of glucose starvation, which unlike glutamine depletion, does not boost CAF macropinocytosis. Notably, not much is known about AMPK activation and function during glutamine depletion. Our preliminary studies suggest that macropinocytosis has a dual purpose in CAFs – it can serve to sustain CAF viability and function, and it can provide secreted amino acids to nourish the tumor cells. Importantly, our in vivo and in vitro examinations of macropinocytosis in normal fibroblasts, as well as in CAFs originating from other tumor types, suggest that glutamine depletion-induced stromal uptake is unique to pancreatic CAFs. Based on these data, our central hypothesis is that glutamine scarcity selectively drives CAMKK2-AMPK-dependent macropinocytosis in CAFs, and that stromal macropinocytosis is a process that can be harnessed in PDAC therapy. In this proposal, we will 1) examine the molecular mechanisms driving the selective role of glutamine in CAF macropinocytosis, 2) functionally characterize stromal macropinocytosis in PDAC, and 3) determine whether the stromal reorganization that occurs with macropinocytosis inhibition can be leveraged for PDAC therapy. This project will be of great significance, novelty and impact, as it will constitute the first evaluation of the role of macropinocytosis in the PDAC tumor stroma and the first analysis to selectively link glutamine starvation to CAMKK2-AMPK signaling. Moreover, because macropinocytosis is important in both the tumor cells and the stroma, our work could have tremendous impact on the development of novel therapeutic modalities for PDAC.

项目概要近年来，人们认识到代谢适应在赋予生存方面所起的作用对于遇到肿瘤微环境严酷的营养匮乏条件的细胞来说具有优势。与该提案特别相关的是目前广泛接受的概念，即巨胞饮作用，一种内吞作用液相摄取机制，通过刺激摄取在肿瘤中发挥氨基酸供应途径的作用。胞外蛋白并靶向其进行溶酶体降解，巨胞饮作用为细胞提供了蛋白质衍生氨基酸的来源，使肿瘤能够避免氨基酸耗尽并在营养物质中生存胰腺导管腺癌 (PDAC) 肿瘤缺乏谷氨酰胺，这是一种重要的营养素。我们发表的 PDAC 细胞研究表明，谷氨酰胺消耗具有促进肿瘤生长的作用。调节巨胞饮作用的能力——根据需要向上或向下调节该过程。该提案中提供的初步数据首次证明谷氨酰胺短缺也会导致从机制上讲，我们将其归因于癌症相关成纤维细胞（CAF）的巨胞饮作用。谷氨酰胺应激诱导的 CAF 巨胞饮摄取 CAMKK2-AMPK 信号，从而导致 Rac1- AMPK 所需的依赖肌动蛋白细胞骨架动力学是一种生物能应激。最常在葡萄糖饥饿的情况下研究的传感器，与谷氨酰胺消耗不同，它不会不促进 CAF 巨胞饮作用值得注意的是，对于 AMPK 的激活和功能知之甚少。我们的初步研究表明，巨胞饮作用在 CAF 中具有双重目的——它可以维持 CAF 的活力和功能，并且可以提供分泌的氨基酸来滋养肿瘤重要的是，我们对正常成纤维细胞以及体内的巨胞饮作用进行了体内和体外检查。源自其他肿瘤类型的 CAF 表明，谷氨酰胺消耗诱导的基质摄取是肿瘤细胞所独有的。根据这些数据，我们的中心假设是谷氨酰胺缺乏选择性地驱动。 CAF 中 CAMKK2-AMPK 依赖性巨胞饮作用，并且基质巨胞饮作用是一个过程可以在 PDAC 治疗中利用。在本提案中，我们将 1) 检查驱动的分子机制。谷氨酰胺在 CAF 大胞饮作用中的选择性作用，2) 功能性表征基质巨胞饮作用 PDAC，以及 3) 确定巨胞饮抑制作用下发生的基质重组是否可以该项目将具有重大意义、新颖性和影响力。首次评估巨胞饮作用在 PDAC 肿瘤基质中的作用，并首次分析选择性地将谷氨酰胺饥饿与 CAMKK2-AMPK 信号传导联系起来，而且，因为巨胞饮作用是对肿瘤细胞和基质都很重要，我们的工作可能会对肿瘤细胞的发育产生巨大影响 PDAC 的新治疗方式。