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: 8259211
• 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/8259211
• 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; rapid growth; research study; second messenger; subcutaneous; therapeutic target; tumor; tumor growth; tumorigenesis

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-¿ (PLC-¿)/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.

恶性神经胶质瘤占脑肿瘤的很大一部分，因为这些肿瘤通常是难治性的。 为了治疗，需要新的治疗方法 ACSVL3（一种脂肪酶）的水平。 酸（FA）代谢，被发现在人类恶性胶质瘤中高度上调，并由 培养的神经胶质瘤细胞中的致癌受体酪氨酸激酶 (RTK) 信号转导 ACSVL3 是 26 种酰基辅酶 A 之一。 合成 (ACS)，“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； 脂质在致癌细胞质信号传导中也具有关键功能。 在人类神经胶质瘤中，我们发现使用 RNA 干扰的 ACSVL3 敲低 (KD) 降低了体外 我们建立了 ACSVL3 表达与人类神经胶质瘤细胞恶性表型之间的相关性。 我们进一步建立了 ACSVL3 表达之间的关系。 通过磷脂酰肌醇-3 激酶 (PI3K)/Akt 和致癌第二信使信号传导 磷脂酶c-¿ (PLC-¿)/二酰基甘油 (DAG) 途径我们发现 ACSVL3 产生特定的通路。 FA-CoA 产品通过 (i) 生成特定结构脂质 (ii) 改变脂质来影响肿瘤发生 直接参与细胞信号传导，或（iii）改变参与膜与特定物质相互作用的脂质 根据我们的初步研究结果，我们还针对 ACSVL3 进行了研究。 对治疗恶性胶质瘤具有治疗价值，并提出以下具体目标：（1） 确定 ACSVL3 缺失对人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中的信号转导，以及 (4) 确定 ACSVL3 如何改变恶性胶质瘤细胞中的信号转导 在目标 1 中，我们将研究细胞增殖、凋亡和自噬。 这些研究在对照和 KD 人神经胶质瘤细胞中进行，以确定 ACSVL3 在肿瘤发生中的特异性。 还将扩展到其他可能在后续目标中有用的神经胶质瘤模型，例如细胞系 内源性表达肿瘤抑制因子 PTEN ACSVL3 在脂质代谢中的功能尚不清楚。 目标 2 提出了填补这一知识空白的研究，该知识也将识别脂质。 与恶性表型相关的通路在目标 3 中，详细分析了 PI3K/Akt 和 PLC-¿ / 在目标 4 中，将研究对照和 ACSVL3 KD 神经胶质瘤细胞中的 DAG 信号通路的影响。 将探讨 ACSVL3 KD 对体内肿瘤发生、脂质代谢改变和 RTK 信号传导的影响 这些研究的结果将奠定机制基础。 对于胶质瘤中 ACSVL3 的上调，查明该酶在致癌 RTK 信号传导和脂质中的作用 代谢，并验证靶向该蛋白在恶性神经胶质瘤中的治疗潜力。