PIP5K1A is a novel mutant KRAS effector and essential for pancreatic cancer cell survival

PIP5K1A 是一种新型突变型 KRAS 效应子，对于胰腺癌细胞的生存至关重要

基本信息

批准号：
10666257
负责人：
Suyong Choi
金额：
$ 15.35万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10666257
关键词：
Amino Acids Animal Cancer Model Applications Grants Attenuated Binding Binding Proteins Biochemical Biological Assay Biological Testing Biopsy CRISPR/Cas technology Cancer Biology Cancer Etiology Cancer Patient Cancer cell line Cell Death Cell Survival Cell physiology Cells Cessation of life Complex Data Databases Disease Drug Targeting Feedback Functional disorder Funding Genes Goals Human In Vitro Incidence Isomerism KRAS2 gene Knock-out Lipids Malignant Neoplasms Malignant neoplasm of pancreas Malignant neoplasm of prostate Mediating Membrane Metabolism Modality Modeling Molecular Mutagenesis Mutate Mutation Null Lymphocytes Pathogenesis Pathway interactions Phosphatidylinositols Phosphotransferases Physiology Production Proliferating Protein Isoforms Proteins Recombinants Regulation Reporting Research Risk Factors Role Route Signal Transduction Site Specificity TP53 gene Testing The Cancer Genome Atlas Therapeutic Agents Tissues United States cancer cell cancer type cell motility cell type druggable target effective therapy human disease inhibitor inositol 4-phosphate mRNA Expression malignant breast neoplasm migration mutant neural new therapeutic target novel novel therapeutics overexpression pancreatic cancer cells pancreatic cancer model protein expression screening translational study tumor tumor progression

项目摘要

PROJECT SUMMARY/ABSTRACT Phosphoinositides are lipid messengers that control essentially all aspects of human physiology such as survival, proliferation, and motility. Disregulation of phosphoinositide signaling thus is closely associated with human diseases including cancer. Phosphatidylinositol 4,5-bisphosphate (PI4,5P2) is the most abundant phosphoinositide species and has a fundamental role in cancer biology by controlling the activity and subcellular localization of PI4,5P2-binding proteins. The majority of cellular PI4,5P2 is generated by phosphatidyl inositol 4- phosphate 5-kinase type 1 (PIP5K1) and the alpha isoform (encoded by the PIP5K1A gene) is often found to be overexpressed in many types of cancer. However, the detailed molecular functions of PIP5K1A in cancer are poorly understood. In this study, we propose to investigate the molecular mechanisms by which PIP5K1A and its product PI4,5P2 synergistically control KRAS in pancreatic cancer which is one of the deadliest diseases with a median survival period of 4-6 months. KRAS is mutated in >90% of pancreatic cancer and mutant KRAS drives all steps of pancreatic cancer progression. Unfortunately, most of mutant KRAS in pancreatic cancer remains undruggable despite decades of extensive efforts. Thus, novel drugging strategies targeting mutant KRAS in pancreatic cancer is an utmost urgency. We found that PIP5K1A associates with mutant KRAS in pancratic cancer cells and, importantly, recombinant mutant KRAS binds to and stimulates the kinase activity of PIP5K1A in vitro. This finding points out that PIP5K1A is a novel KRAS effector. Consistently, PI4,5P2 production was increased in wild-type KRAS and more dramatically in mutant KRAS expressing cells compared to KRAS-null cells. Moreover, PIP5K1A protein expression was profoundly elevated in pancreatic cancer cells and tissues and depletion of PIP5K1A significantly reduced survival of pancreatic cancer cells harboring mutant KRAS. This makes PIP5K1A a key drug target in pancratic cancer. It is well-documented that PI4,5P2 binds to and activates KRAS by facilitating membrane association and clustering. We hypothesize that 1) KRAS stimulates PI4,5P2 production by PIP5K1A and the generated PI4,5P2 further activates KRAS and its downstream signaling, 2) this positive feedback mechanism sustains constitutive activation of KRAS signaling in pancreatic cancer, and 3) blockade of PIP5K1A consequently attenuates KRAS signaling, leading to pancreatic cancer cell death. To test these hypotheses we will explore 1) the protein-protein and protein-phosphoinositide interactions governing the PIP5K1A-KRAS axis at the molecular level and 2) the impacts of this novel mechanism in pancreatic cancer cell survival/proliferation and motility. This project will provide pivotal information how KRAS signaling is maintained in pancreatic cancer and illuminate new routes to target mutant KRAS by the understudied kinase PIP5K1A.

项目概要/摘要磷酸肌醇是脂质信使，基本上控制着人类生理学的所有方面，例如生存、增殖和运动性。因此，磷酸肌醇信号传导失调与人类密切相关。疾病，包括癌症。磷脂酰肌醇 4,5-二磷酸 (PI4,5P2) 含量最丰富磷酸肌醇种类，通过控制活性和亚细胞在癌症生物学中具有基本作用 PI4,5P2 结合蛋白的定位。大多数细胞 PI4,5P2 由磷脂酰肌醇 4- 产生磷酸 5 激酶 1 型 (PIP5K1) 和 α 异构体（由 PIP5K1A 基因编码）经常被发现在许多类型的癌症中过度表达。然而，PIP5K1A 在癌症中的详细分子功能尚不清楚。不太了解。在这项研究中，我们打算研究 PIP5K1A 和其产品PI4、5P2协同控制胰腺癌中的KRAS，胰腺癌是最致命的疾病之一中位生存期为 4-6 个月。 > 90% 的胰腺癌和突变 KRAS 驱动器中 KRAS 发生突变胰腺癌进展的所有步骤。不幸的是，胰腺癌中大部分突变的 KRAS 仍然存在尽管经过数十年的努力，仍无法治愈。因此，针对突变 KRAS 的新药物策略胰腺癌是当务之急。我们发现 PIP5K1A 与胰腺中突变的 KRAS 相关癌细胞，重要的是，重组突变体 KRAS 结合并刺激 PIP5K1A 的激酶活性体外。这一发现指出PIP5K1A是一种新型的KRAS效应子。 PI4,5P2 的产量始终如一与 KRAS 缺失相比，野生型 KRAS 增加，突变型 KRAS 表达细胞中增加更显着细胞。此外，PIP5K1A 蛋白表达在胰腺癌细胞和组织中显着升高， PIP5K1A 的缺失显着降低了携带突变 KRAS 的胰腺癌细胞的存活率。这使 PIP5K1A 成为胰腺癌的关键药物靶点。有充分证据表明 PI4,5P2 结合并激活 KRAS 通过促进膜关联和聚类。我们假设 1) KRAS 刺激 PI4,5P2 PIP5K1A 的产生和生成的 PI4,5P2 进一步激活 KRAS 及其下游信号传导，2) 正反馈机制维持胰腺癌中 KRAS 信号传导的组成型激活，3) 阻断 PIP5K1A 会减弱 KRAS 信号传导，导致胰腺癌细胞死亡。测试我们将探讨这些假设 1）蛋白质-蛋白质和蛋白质-磷酸肌醇相互作用控制分子水平上的 PIP5K1A-KRAS 轴以及 2) 这种新机制对胰腺癌细胞的影响生存/增殖和运动性。该项目将提供如何维护 KRAS 信号的关键信息胰腺癌中的研究，并阐明了通过正在研究的激酶 PIP5K1A 靶向突变 KRAS 的新途径。