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（由申请人提供）：恶性神经胶质瘤占脑肿瘤的很大一部分。由于这些肿瘤通常是对治疗的难治性，因此需要采用新的新型治疗方法。发现ACSVL3的水平是脂肪酸（FA）代谢的酶，发现在人类恶性神经胶质瘤中高度上调，并通过培养的神经胶质瘤细胞中的致癌受体酪氨酸激酶（RTK）信号传导诱导。 ACSVL3是26个酰基-COA合成酶（AC）之一，它们“激活” FAS以参与生物合成，降解和调节性下游代谢途径。快速肿瘤生长需要高膜脂质合成速率。这些脂质在致癌细胞质信号传导中也具有关键功能。使用人神经胶质瘤的公认临床前模型，我们发现使用RNA干扰的ACSVL3敲低（KD）降低了人神经胶质瘤细胞的体外恶性表型。我们在体内胶质瘤异种移植物中建立了ACSVL3表达与肿瘤发生之间的相关性。我们通过磷脂酰肌醇-3激酶（PI3K）/AKT和磷脂酶C-3（PLC-3）/二酰基甘油（DAG）途径在ACSVL3表达与致癌的第二信号信号之间建立了关系。我们假设ACSVL3会产生特定的FA-COA产物，该产品通过（i）通过（i）产生特定的结构脂质（ii）直接涉及细胞信号传导涉及的脂质的特定结构脂质，或（iii）改变与特异性肿瘤信号蛋白的膜相互作用所涉及的脂质。根据我们的初步发现，我们还假设靶向ACSVL3在治疗恶性神经胶质瘤方面将具有治疗价值，并提出以下具体目的：（1）确定ACSVL3耗竭对人膜瘤细胞的体外表型的影响，以确定对ACSVL3 DEPERS的体外表型的影响，（2） （3）为了阐明ACSVL3 KD如何改变恶性神经胶质瘤细胞中的信号转导，（4）确定ACSVL3耗竭如何抑制神经胶质瘤肿瘤性。在AIM 1中，我们将研究对照和KD人神经胶质瘤细胞中的细胞增殖，凋亡和自噬，以确定肿瘤发生中ACSVL3的特异性。这些研究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，例如内源表达肿瘤抑制剂PTEN的细胞系。 ACSVL3在脂质代谢中的功能均以正常或癌细胞而闻名。 AIM 2提出了研究，以填补这一空白，以确定与恶性表型相关的脂质途径。在AIM 3中，将对对照和ACSVL3 KD神经胶质瘤细胞中的PI3K/ AKT和PLC-？/ DAG信号通路进行详细分析。在AIM 4中，ACSVL3 KD对体内肿瘤发生，脂质代谢的改变和RTK信号的影响，无论是在皮下和颅内异种移植物中。这些研究的结果将建立神经胶质瘤中ACSVL3上调的机械基础，查明该酶在致癌性RTK信号传导和脂质代谢中的作用，并验证靶向该蛋白质在恶性神经胶质瘤中的治疗潜力。 公共卫生相关性：恶性神经胶质瘤在儿科和成人人群中占脑肿瘤的很大一部分，并且需要采用新的新型治疗方法。在此应用中，我们将研究一种脂肪酸代谢的酶，我们在人类恶性神经胶质瘤中已被确定为独特的上调。这些研究的结果将对该酶有助于恶性表型的机制进行批判性评估，以及靶向这种酶在神经胶质瘤中的潜在治疗益处。