Regulation of Nutrient Stress-Induced Macropinocytosis in Pancreatic Ductal Adenocarcinoma

胰腺导管腺癌中营养应激诱导的巨胞饮作用的调节

基本信息

批准号：
10677661
负责人：
Cosimo Commisso
金额：
$ 45.68万
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：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10677661
关键词：
Acceleration Actins Amino Acids Animal Model Biological Models Bypass Cancer Etiology Cell Proliferation Cell Survival Cells Cessation of life Consumption Cytoskeleton Data Development Disease EGFR inhibition Ecosystem Enzymes Epidermal Growth Factor Receptor Evaluation Extracellular Protein Funding Gene Expression Glutamine Growth Human In Vitro Ligands Liquid substance Malignant Neoplasms Metabolic Metabolic stress Metabolism Microtubules Modality Molecular Norleucine Normal tissue morphology Nutrient Oncogenes Pancreatic Ductal Adenocarcinoma Pathway interactions Phosphorylation Phosphotransferases Play Process Production Proliferating Proteins Reaction Regulation Research Role Route Signal Transduction Small Interfering RNA Source Specimen Starvation Strategic Planning Stress Testing Tumor Suppressor Proteins United States Work analog atypical protein kinase C cancer cell cancer therapy cell growth deprivation experimental study glutamine analog in vivo knock-down mimetics mimicry neoplastic cell new therapeutic target novel novel therapeutics pancreatic ductal adenocarcinoma cell pancreatic ductal adenocarcinoma model response stress tolerance tumor tumor growth tumor microenvironment uptake

项目摘要

PROJECT SUMMARY Recent years have witnessed a growing appreciation of the role that metabolic reprogramming plays in conferring growth and survival advantages to tumor cells. Of particular relevance to this proposal is the now widely accepted notion that pancreatic ductal adenocarcinoma (PDAC) cells depend on macropinocytosis as an amino acid supply route. By stimulating the uptake of extracellular protein and targeting it for lysosomal degradation, the macropinocytosis pathway provides cancer cells with a source of protein-derived amino acids, allowing tumors to circumvent amino acid depletion and survive nutrient stress. Glutamine is a vital nutrient to tumors as it supports the metabolic reactions necessary to sustain tumor cell growth; however, hearty consumption by the tumor often leads to a glutamine-depleted tumor ecosystem. Our previously funded research demonstrated that glutamine depletion in PDAC tumors has the capacity to modulate macropinocytosis – dialing the process up or down as required. We attributed this inducible form of macropinocytic uptake to the activation of EGFR-Pak signaling. Interestingly, we have found that macropinocytosis is also induced by a glutamine structural analog that broadly suppresses glutamine metabolism; however, uptake in this setting does not employ EGFR signaling. Since the inhibition of glutamine metabolism is being actively pursued as a therapy for cancer, we set out to decipher how glutamine mimicry might elicit macropinocytosis as an adaptive response. We performed a high- throughput siRNA screen and identified the atypical protein kinase C (aPKC) subfamily of kinases, PKCι and PKCζ, as the most potent regulators of uptake. This proposal is based on our preliminary data demonstrating that knockdown of either PKCι or PKCζ not only suppresses macropinocytosis caused by glutamine analogs, but also abrogates uptake caused by glutamine starvation, suggesting that the aPKCs are general modulators of nutrient stress-induced macropinocytosis. Based on these data, our central hypothesis is that aPKC signaling is integral to nutrient stress-driven macropinocytosis and that the aPKCs support metabolic stress tolerance in PDAC tumors. We will 1) examine the molecular mechanisms underlying the role of aPKCs in nutrient stress- driven macropinocytosis and 2) determine the functional consequences of suppressing aPKC-dependent macropinocytosis in PDAC. This project constitutes the first evaluation of the role that the aPKCs play in the modulation of macropinocytosis and the first to interrogate aPKC function from the perspective of glutamine supply. Moreover, because our work will establish aPKC-dependent macropinocytosis as a critical metabolic adaptation in response to glutamine mimetics, our findings could have tremendous impact on the development of novel therapeutic modalities for PDAC.

项目概要近年来，人们越来越认识到代谢重编程在赋予与该提议特别相关的是现在被广泛接受的观点。胰腺导管腺癌 (PDAC) 细胞依赖巨胞饮作用作为氨基酸通过刺激细胞外蛋白的摄取并靶向其进行溶酶体降解，巨胞饮途径为癌细胞提供蛋白质衍生氨基酸的来源，使肿瘤避免氨基酸消耗并抵御营养应激。谷氨酰胺是肿瘤的重要营养素。支持维持肿瘤细胞生长所需的代谢反应；然而，我们之前资助的研究表明，肿瘤通常会导致谷氨酰胺耗尽的肿瘤生态系统。 PDAC 肿瘤中谷氨酰胺的消耗能够调节巨胞饮作用——加快该过程或我们将这种诱导形式的巨胞饮摄取归因于 EGFR-Pak 的激活。事实上，我们发现巨胞饮作用也是由谷氨酰胺结构类似物诱导的。广泛抑制谷氨酰胺代谢；然而，在这种情况下的摄取不利用 EGFR 信号传导。由于人们正在积极寻求抑制谷氨酰胺代谢作为癌症治疗方法，因此我们着手破译谷氨酰胺拟态如何引发巨胞饮作用作为适应性反应。吞吐量 siRNA 筛选并鉴定了激酶的非典型蛋白激酶 C (aPKC) 亚家族、PKCι 和 PKCδ，作为最有效的吸收调节剂，该建议基于我们的初步数据证明。敲低 PKCι 或 PKCζ 不仅可以抑制谷氨酰胺类似物引起的巨胞饮作用，而且还消除了谷氨酰胺饥饿引起的摄取，表明 aPKC 是通用调节剂基于这些数据，我们的中心假设是 aPKC 信号传导。是营养应激驱动的巨胞饮作用的组成部分，并且 aPKC 支持代谢应激耐受性我们将 1) 检查 aPKC 在营养应激中作用的分子机制 - 驱动的巨胞饮作用和 2) 确定抑制 aPKC 依赖性的功能后果 PDAC 中的巨胞饮作用这是对 aPKC 在 PDAC 中发挥的作用的首次评估。调节巨胞饮作用并首次从谷氨酰胺的角度探讨 aPKC 功能此外，因为我们的工作将建立 aPKC 依赖性巨胞饮作用作为一种关键的代谢。针对谷氨酰胺模拟物的适应，我们的发现可能会对发育产生巨大影响 PDAC 的新治疗方式。