Molecular Mechanisms of Regulation and Modulation of Sphingosine Kinase 1 Activity in Cancer

癌症中鞘氨醇激酶 1 活性调控的分子机制

• 批准号: 9123143
• 负责人: Michael John Pulkoski-Gross
• 金额: $ 3.34万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9123143
• 关键词: Acetates; Active Sites; Affect; Apoptosis; Apoptotic; Area; Arginine; Binding; Binding Sites; Biochemical; Biological; Biological Assay; Biology; Breast; Cancer Biology; Cancer Etiology; Cancer Patient; Cancer cell line; Catalysis; Cause of Death; Cell Survival; Cell membrane; Cells; Cellular biology; Ceramides; Charge; Colon; Development; Disease; Electrostatics; Enzymes; Equilibrium; FDA approved; Fluorescence; Future; Glare; Glioblastoma; Goals; In Vitro; Investigation; Knowledge; Link; Lipids; Liposomes; Lung; Lysine; Malignant Epithelial Cell; Malignant Neoplasms; Maps; Mediating; Membrane; Metabolism; Molecular; Monitor; Neoplasm Metastasis; Pathway interactions; Phosphatidic Acid; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositol Phosphates; Phosphatidylinositols; Phospholipid Metabolism; Phospholipids; Phosphorylation; Phosphotransferases; Play; Production; Property; Prostate; Proteins; Regulation; Renal Cell Carcinoma; Research; Role; SPHK1 enzyme; Signal Transduction; Site; Small Interfering RNA; Sphingolipids; Sphingosine; Sphingosine-1-Phosphate Receptor; Structure; Surface; Techniques; Testing; Therapeutic; Tumor Volume; United States; United States Food and Drug Administration; Work; Xenograft Model; angiogenesis; base; biophysical techniques; blood vessel development; cancer cell; cancer therapy; cancer type; cell growth; cell motility; drug development; ezrin; inhibitor/antagonist; inorganic phosphate; knock-down; malignant breast neoplasm; migration; mutant; novel; outcome forecast; overexpression; phorbol-12-myristate; public health relevance; response; sensor; sphingosine 1-phosphate; sphingosine kinase; structural biology; tumor progression

 DESCRIPTION (provided by applicant): The central goal of this proposal is to understand how sphingosine kinase 1 (SK1) is regulated in order to build better inhibitors as alternative cancer therapeutics. SK1 is an important enzyme in the sphingolipid metabolism pathway as it sits between the pro-apoptotic sphingolipids ceramide and sphingosine and the pro- survival and pro-angiogenic lipid sphingosine-1-phosphate (S1P). S1P has been shown to have both intra- and inter-cellular signaling properties that play an important role in angiogenesis and invasion. SK1 has been detected in numerous different cancer types and cell lines. Additionally, SK1 activity has been shown to be over-expressed in several different cancer types. SK1 activity has been previously shown to be modulated by anionic phospholipids (APLs) which can be found in the plasma membrane of all cells. Furthermore, it has been shown that SK1 can translocate to the plasma membrane where its substrate is located. Despite the strong underlying support for the roles of SK1 and S1P in cancer, there is a lack in understanding of the molecular mechanisms that control SK1 activation and ultimately S1P levels. Based on these premises, we seek in Specific Aim 1 to determine the molecular mechanism of SK1 activation by APLs, both in vitro, in cells, and through structural biology, which we suggest is mediated through a novel APL binding site. Additionally, we will look at the effects of the SK1 membrane binding mutants on S1P-mediated cancer biological responses including phosphorylation of the migration and invasion associated protein Ezrin. Furthermore, I have identified novel interactions between SK1 and phosphatidylinositol phosphates (PIPs) which can also be found at the plasma membrane. I have shown that certain PIPs can de-activate SK1 even in the presence of activating APLs. This proposal, in specific Aim 2, aims at understanding these interaction and their biological consequences to cancer cell invasion and angiogenesis. Currently, there are no inhibitors of SK1 approved by the U.S. Food and Drug Administration for the treatment of any disease. Therefore, there is a need for the development of SK1 inhibitors as alternative therapeutic options for cancer. The overarching goal of these studies is to understand the molecular mechanism of SK1 activation by APLs and how PIPs can affect SK1 activity. Understanding the mechanisms by which SK1 activity is allosterically modulated will open the door to a new class of SK1 inhibitors which target SK1s ability to bind to the membrane, therefore limiting its access to its substrate. Targeting S1P production allows for a new avenue of anti-cancer therapies.

 描述（由申请人提供）：该提案的中心目标是了解鞘氨醇激酶 1 (SK1) 是如何调节的，以便构建更好的抑制剂作为替代癌症疗法。 SK1 是鞘脂代谢途径中的重要酶，因为它位于促凋亡鞘脂神经酰胺和鞘氨醇与促存活和促血管生成脂质 1-磷酸鞘氨醇 (S1P) 之间。 S1P 已被证明具有细胞内和细胞间信号传导特性，在血管生成和侵袭中发挥重要作用。 SK1 已在多种不同的癌症类型和细胞系中检测到。此外，SK1 活性已被证明在几种不同的癌症类型中过度表达。 先前已证明 SK1 活性受到阴离子磷脂 (APL) 的调节，阴离子磷脂存在于所有细胞的质膜中。此外，研究表明 SK1 可以易位至其底物所在的质膜。尽管 SK1 和 S1P 在癌症中的作用得到了强有力的支持，但人们对控制 SK1 激活和最终 S1P 水平的分子机制仍缺乏了解。基于这些前提，我们在具体目标 1 中寻求确定 APL 在体外、细胞内以及通过结构生物学激活 SK1 的分子机制，我们认为这是通过一个新的 APL 结合位点介导的。此外，我们将研究 SK1 膜结合突变体对 S1P 介导的癌症生物反应的影响，包括迁移和侵袭相关蛋白 Ezrin 的磷酸化。 此外，我还发现了 SK1 和磷脂酰肌醇磷酸 (PIP) 之间的新相互作用，这种相互作用也可以在质膜上发现。我已经证明，即使存在激活的 APL，某些 PIP 也可以使 SK1 失活。该提案的具体目标 2 旨在了解这些相互作用及其对癌细胞侵袭和血管生成的生物学影响。 目前，美国食品和药物管理局还没有批准用于治疗任何疾病的 SK1 抑制剂。因此，需要开发SK1抑制剂作为癌症的替代治疗选择。这些研究的首要目标是了解 APL 激活 SK1 的分子机制以及 PIP 如何影响 SK1 活性。了解 SK1 活性变构调节机制将为新型 SK1 抑制剂打开大门，该抑制剂针对 SK1 与膜结合的能力，从而限制其对其底物的接触。以 S1P 生产为目标为抗癌治疗开辟了一条新途径。