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.

项目摘要/摘要 磷酸肌醇是脂质使者，它基本控制人类生理的各个方面，例如生存， 增殖和运动。因此，磷酸肌醇信号传导的脱离与人类密切相关 包括癌症在内的疾病。磷脂酰肌醇4,5-双磷酸（PI4,5P2）是最丰富的 磷酸肌醇物种，通过控制活性和亚细胞来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是由磷脂酰肌醇4-产生的 通常发现磷酸5-激酶1型（PIP5K1）和α同工型（由PIP5K1A基因编码）是 在许多类型的癌症中过表达。但是，癌症中PIP5K1A的详细分子功能是 理解不佳。在这项研究中，我们建议研究PIP5K1A和 它的产品PI4,5P2协同控制胰腺癌的KRAS，这是最致命的疾病之一 中位生存期为4-6个月。 KRAS在胰腺癌和突变的KRAS驱动器中> 90％ 胰腺癌进展的所有步骤。不幸的是，胰腺癌中的大多数突变KRA仍然存在 尽管做了数十年的广泛努力，但不得不难。因此，针对突变kras的新型吸毒策略 胰腺癌是最紧迫的。我们发现PIP5K1A与胰腺中的突变kras相关 癌细胞，重要的是重组突变体KRAS与PIP5K1A的激酶活性结合并刺激 体外。这一发现指出，PIP5K1A是一种新颖的KRAS效应器。始终如一，PI4,5P2的生产是 与Kras-Null相比 细胞。此外，在胰腺癌细胞和组织中，PIP5K1A蛋白表达明显升高 PIP5K1A的耗竭显着降低了具有突变体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标。有充分记录的PI4,5P2与并激活 KRAS通过促进膜协会和聚类。我们假设1）KRAS刺激PI4,5P2 PIP5K1A和生成的PI4,5P2的生产进一步激活了KRAS及其下游信号，2） 阳性反馈机制维持胰腺癌中KRAS信号传导的组成型激活，3） 因此，PIP5K1A的封锁会减弱KRAS信号传导，导致胰腺癌细胞死亡。测试 这些假设我们将探索1）蛋白质 - 蛋白质蛋白和蛋白磷酸肌醇相互作用的相互作用 PIP5K1A-KRAS轴在分子水平和2）这种新机制在胰腺癌细胞中的影响 生存/增殖和运动。该项目将提供关键信息如何保持KRAS信号传导 在胰腺癌中，通过研究研究的激酶PIP5K1A照亮了针对突变体KRA的新途径。