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

• 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
• 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

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.

项目总结/摘要 磷酸肌醇是脂质信使，基本上控制人类生理学的所有方面，如生存， 增殖和运动。因此，磷酸肌醇信号转导的失调与人类免疫功能密切相关。 包括癌症在内的疾病。磷脂酰肌醇4，5-二磷酸（PI 4，5 P2）是最丰富的 磷酸肌醇种类，通过控制活性和亚细胞在癌症生物学中发挥重要作用 PI 4，5 P2结合蛋白的定位。大多数细胞PI 4，5 P2是由磷脂酰肌醇4- 磷酸5-激酶1型（PIP 5 K1）和α亚型（由PIP 5 K1 A基因编码）通常被发现是 在许多癌症中过度表达。然而，PIP 5 K1 A在癌症中的详细分子功能是 不太了解。在这项研究中，我们建议研究PIP 5 K1 A和 其产物PI 4，5 P2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。KRAS在>90%的胰腺癌中发生突变，突变的KRAS驱动 胰腺癌进展的所有步骤。不幸的是，胰腺癌中的大多数突变KRAS仍然存在， 尽管几十年来的广泛努力，因此，靶向突变型KRAS的新的给药策略可以用于治疗糖尿病。 胰腺癌是当务之急我们发现PIP 5 K1 A与pancratic中突变的KRAS相关， 癌细胞，重要的是，重组突变KRAS结合并刺激PIP 5 K1 A的激酶活性 体外这一发现表明PIP 5 K1 A是一种新的KRAS效应子。因此，PI 4，5 P2的生产是 在野生型KRAS中增加，并且与KRAS缺失细胞相比，在突变型KRAS表达细胞中更显著 细胞此外，PIP 5 K1 A蛋白表达在胰腺癌细胞和组织中显著升高， PIP 5 K1 A的缺失显著降低了携带突变KRAS的胰腺癌细胞的存活。这 使PIP 5 K1 A成为胰腺癌的关键药物靶点。有充分的证据表明，PI 4，5 P2结合并激活 KRAS通过促进膜缔合和聚集。我们假设1）KRAS刺激PI 4，5 P2 PIP 5 K1 A的产生和产生的PI 4，5 P2进一步激活KRAS及其下游信号传导， 正反馈机制维持胰腺癌中KRAS信号传导的组成性激活，以及3） 因此，阻断PIP 5 K1 A会减弱KRAS信号传导，导致胰腺癌细胞死亡。测试 这些假设，我们将探讨1）蛋白质-蛋白质和蛋白质-磷酸肌醇的相互作用， PIP 5 K1 A-KRAS轴在分子水平上的作用和2）这种新机制在胰腺癌细胞中的影响 存活/增殖和运动性。该项目将提供关键信息KRAS信号是如何维持的 在胰腺癌中，并阐明了通过未充分研究的激酶PIP 5 K1 A靶向突变KRAS的新途径。