Acyl-CoA synthetase ACSVL3 in Malignant Glioma: Metabolism and Oncogenic Cellular

恶性胶质瘤中的酰基辅酶 A 合成酶 ACSVL3：代谢和致癌细胞

• 批准号: 8067910
• 负责人: Paul A. WATKINS
• 金额: $ 34.51万
• 依托单位: HUGO W. MOSER RES INST KENNEDY KRIEGER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8067910
• 关键词: 1,2-diacylglycerol; Accounting; Adult; Affect; Apoptosis; Appearance; Autophagocytosis; Behavior; Brain Neoplasms; Cell Line; Cell Proliferation; Cells; Cellular Membrane; Childhood; Coenzyme A; Coenzyme A Ligases; Data; Diglycerides; Environment; Enzymes; Event; Family; Family member; Fatty Acids; Glioma; Growth; Histologic; Human; In Vitro; Knowledge; Lipids; Malignant - descriptor; Malignant Glioma; Mediating; Membrane; Membrane Lipids; Metabolic; Metabolic Pathway; Metabolism; Modeling; Mus; Neuroglia; Normal Cell; Oncogenic; PTEN gene; Pathway interactions; Phenotype; Phosphatidylinositols; Phospholipase; Phospholipase C; Phosphorylation; Phosphotransferases; Population; Pre-Clinical Model; Proteins; RNA Interference; Reaction; Receptor Protein-Tyrosine Kinases; Refractory; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Signaling Molecule; Signaling Protein; Specificity; Structure; Therapeutic; Translating; Tumor Suppressor Proteins; Tumorigenicity; Up-Regulation; Work; Xenograft Model; Xenograft procedure; base; cancer cell; cell growth regulation; fatty acid metabolism; glioma cell line; in vivo; knock-down; lipid metabolism; malignant phenotype; novel; novel therapeutic intervention; overexpression; public health relevance; rapid growth; research study; second messenger; subcutaneous; therapeutic target; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Malignant glioma accounts for a significant percentage of brain tumors. As these tumors are typically refractory to treatment, there is a need for new and novel therapeutic approaches. Levels of ACSVL3, an enzyme of fatty acid (FA) metabolism, were found to be highly upregulated in human malignant gliomas and were induced by oncogenic receptor tyrosine kinase (RTK) signaling in cultured glioma cells. ACSVL3 is one of 26 acyl-CoA synthetases (ACS) that "activate" FAs for their participation in biosynthetic, degradative, and regulatory downstream metabolic pathways. Rapid tumor growth requires high rates of membrane lipid synthesis; these lipids also have key functions in oncogenic cytoplasmic signaling. Using a well-established preclinical model of human glioma, we found that ACSVL3 knockdown (KD) using RNA interference decreased the in vitro malignant phenotype of human glioma cells. We established a correlation between ACSVL3 expression and tumorigenesis in glioma xenografts in vivo. We further established a relationship between ACSVL3 expression and oncogenic second messenger signaling via the phosphatidyl inositol-3 kinase (PI3K)/Akt and phospholipase c-3 (PLC-3)/diacylglycerol (DAG) pathways. We hypothesize that ACSVL3 generates specific FA-CoA products that influence oncogenesis by (i) generating specific structural lipids (ii) altering lipids involved directly in cell signaling, or (iii) altering lipids involved in membrane interactions with specific oncogenic signaling proteins. Based on our preliminary findings, we also hypothesize that targeting ACSVL3 will be of therapeutic value in treating malignant glioma, and propose the following Specific Aims: (1) To identify the consequences of ACSVL3 depletion on the in vitro phenotype of human glioma cell lines, (2) To identify the consequences of ACSVL3 depletion on lipid metabolism in malignant glioma cells, (3) To elucidate how ACSVL3 KD alters signal transduction in malignant glioma cells, and (4) To determine how ACSVL3 depletion inhibits glioma tumorigenicity. In Aim 1 we will investigate cell proliferation, apoptosis, and autophagy in control and KD human glioma cells to determine the specificity for ACSVL3 in oncogenesis. These studies will also be extended to other glioma models that may prove useful in subsequent Aims, such as cell lines that endogenously express the tumor suppressor PTEN. The function of ACSVL3 in lipid metabolism is not known for either normal or cancer cells. Aim 2 proposes studies to fill this gap in knowledge that will also identify lipid pathways that correlate with the malignant phenotype. In Aim 3, detailed analyses of the PI3K/Akt and PLC-?/ DAG signaling pathways in control and ACSVL3 KD glioma cells will be carried out. In Aim 4, effects of ACSVL3 KD on in vivo tumorigenesis, alterations in lipid metabolism, and RTK signaling will be explored, both in subcutaneous and in intracranial xenografts. The results of these studies will establish the mechanistic basis for ACSVL3 upregulation in glioma, pinpoint the role of this enzyme in oncogenic RTK signaling and lipid metabolism, and validate the therapeutic potential of targeting this protein in malignant glioma. PUBLIC HEALTH RELEVANCE: Malignant glioma accounts for a significant percentage of brain tumors in both the pediatric and adult populations, and there is a need for new and novel therapeutic approaches. In this application we will investigate an enzyme of fatty acid metabolism that we have identified as uniquely upregulated in human malignant glioma. Results of these studies will provide a critical assessment of the mechanism by which this enzyme contributes to the malignant phenotype, and the potential therapeutic benefit of targeting this enzyme in glioma.

描述(申请人提供)：恶性胶质瘤在脑肿瘤中占很大比例。由于这些肿瘤通常难以治疗，因此需要新的治疗方法。ACSVL3是一种脂肪酸(FA)代谢酶，在人脑恶性胶质瘤中高度上调，并受致癌受体酪氨酸激酶(RTK)信号的诱导。ACSVL3是26个酰基辅酶A合成酶(acyl-CoA synthetase，ACS)之一，它“激活”FA参与生物合成、降解和调节下游代谢途径。肿瘤的快速生长需要高速率的膜脂合成；这些脂类也在致癌细胞质信号转导中起关键作用。利用已建立的人脑胶质瘤临床前模型，我们发现使用RNA干扰的ACSVL3基因敲除(KD)降低了人脑胶质瘤细胞的体外恶性表型。我们在脑胶质瘤异种移植瘤中建立了ACSVL3表达与肿瘤发生的相关性。我们进一步建立了ACSVL3的表达与通过磷脂酰肌醇-3激酶(PI3K)/Akt和磷脂酶c-3(PLC-3)/二酰甘油(DAG)途径的致癌第二信使信号之间的关系。我们假设ACSVL3产生特定的FA-CoA产物，通过(I)产生特定的结构脂(Ii)改变直接参与细胞信号的脂类，或(Iii)改变参与与特定致癌信号蛋白的膜相互作用的脂类来影响肿瘤的发生。根据我们的初步发现，我们还假设以ACSVL3为靶点将在治疗恶性胶质瘤方面具有治疗价值，并提出以下具体目标：(1)确定ACSVL3缺失对人脑胶质瘤细胞系体外表型的影响，(2)确定ACSVL3缺失对恶性胶质瘤细胞脂质代谢的影响，(3)阐明ACSVL3 KD如何改变恶性胶质瘤细胞的信号转导，以及(4)确定ACSVL3缺失如何抑制胶质瘤的发生。在目标1中，我们将研究对照和KD人脑胶质瘤细胞的增殖、凋亡和自噬，以确定ACSVL3在肿瘤发生中的特异性。这些研究还将扩展到其他可能被证明对后续目标有用的胶质瘤模型，例如内源性表达肿瘤抑制因子PTEN的细胞系。无论是正常细胞还是癌细胞，ACSVL3在脂类代谢中的作用尚不清楚。目标2建议进行研究，以填补这一知识空白，也将确定与恶性表型相关的脂类途径。在目标3中，将对对照和ACSVL3KD胶质瘤细胞中的PI3K/Akt和PLC-β/DAG信号通路进行详细的分析。在目标4中，将探索ACSVL3KD在皮下和颅内异种移植中对体内肿瘤发生、脂代谢变化和RTK信号的影响。这些研究结果将为ACSVL3在胶质瘤中上调的机制奠定基础，明确该酶在致癌RTK信号转导和脂质代谢中的作用，并验证该蛋白在恶性胶质瘤中的治疗潜力。 公共卫生相关性：恶性胶质瘤在儿童和成人人群中都占脑肿瘤的很大比例，需要新的和新的治疗方法。在这项应用中，我们将研究一种脂肪酸代谢酶，我们已经确定这种酶在人类恶性胶质瘤中唯一上调。这些研究的结果将为该酶促进恶性表型的机制以及靶向该酶在胶质瘤中的潜在治疗益处提供关键的评估。