Ceramide, Membrane Glycolipids and Glycoprotein Expression

神经酰胺、膜糖脂和糖蛋白表达

• 批准号: 7350165
• 负责人: Myles C. Cabot
• 金额: $ 44.58万
• 依托单位: SAINT JOHN'S CANCER INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7350165
• 关键词: 4-propionyloxy-4-phenyl-N-methylpiperidine; ABCB1 gene; AIDS/HIV problem; ATP-Binding Cassette Transporters; Animal Model; Antibiotics; Apoptosis; Bacteria; Biological Models; Cancer cell line; Carrier Proteins; Cell model; Cells; Ceramide glucosyltransferase; Ceramides; Cerebrosides; Communicable Diseases; Disease; Down-Regulation; Doxorubicin; Drug Kinetics; Drug resistance; Enzymes; Funding; Gangliosides; Gene Expression; Generations; Glucose; Glucosylceramides; Glycolipids; Glycoproteins; Goals; HIV Protease Inhibitors; Human; In Vitro; Knowledge; Lead; Leishmaniasis; Lipid Biochemistry; Lipids; Malaria; Malignant - descriptor; Malignant Neoplasms; Mammary Neoplasms; Membrane; Metabolism; Methods; Mission; Modeling; Molecular and Cellular Biology; Multi-Drug Resistance; Nature; Nitrous Oxide; Outcome; P-Glycoprotein; P-Glycoproteins; Pharmaceutical Preparations; Phenotype; Play; Protein Family; Protein Overexpression; Proteins; Regulation; Research; Research Personnel; Role; Staging; Testing; Therapeutic; Tumor Biology; United States National Institutes of Health; Vertebral column; Vision; Widespread Disease; Work; Xenograft Model; antitumor agent; cancer cell; chemotherapy; clinical effect; concept; drug sensitivity; human disease; improved; in vitro Model; in vivo; inhibitor/antagonist; irradiation; lipid metabolism; malignant breast neoplasm; member; novel strategies; practical application; programs; protein expression; research study; response; tumor; tumor xenograft

DESCRIPTION (provided by applicant): This project will determine the influence of ceramide, ceramide metabolites, and glucosylceramide synthase (GCS) on expression of the multidrug-resistant phenotype, using cancer cells in vitro, and tumor xenographs in vivo, as model systems. GCS catalyzes the formation of glucosylceramide (GC), the building block of higher glycolipids (cerebrosides, gangliosides). Glycolipids such as GC are also substrates for ABC transporter proteins, of which the MDR1 protein, P-glycoprotein (P-gp) is a member. Overexpression of MDR1/P-gp in cells represents a major impediment to effective treatment of many infectious and malignant diseases. Our objective is to improve treatment of disease. If lipids are involved in expression of the MDR1 phenotype, then blocking lipid metabolism at a specific juncture may be a means of limiting multidrug resistance. Many agents - chemotherapy drugs, nitrous oxide, gamma-irradiation - promote an increase in cellular ceramide, which elicits apoptosis. However, high levels of ceramide can also trigger overexpression of GCS due to increased availability of the enzymes lipoidal substrate, leading to elevated levels of GC. Because of the relationship between chemotherapy drugs and ceramide generation, and because high levels of GC are found in multidrug-resistant cancer cells and tumors, we hypothesize that lipids enhance expression of the multidrug-resistant phenotype. This enhancement would dull cellular responses to antibiotics, antitumor agents, and HIV protease inhibitors. The aims of this proposal are: 1. to determine the influence of GCS on MDR1/P-gp expression; 2. to determine the influence of GCS modulation by PPMP, a GCS inhibitor, on MDR1/P-gp expression and response to doxorubicin in an in vitro multidrug-resistant breast tumor xenograft model; 3. to determine the influence of lipids (ceramide, glycolipids) on expression of the multidrug-resistant phenotype, 4. to determine the influence of chemotherapy drugs on GCS and MDR1 expression. We have ordered the Aims to facilitate testing of proof of principle. Aim 1 will demonstrate the power of targeting GCS as an approach to limiting MDR1 expression, using in vitro models. Aim 2, using animal models, will evaluate the power of targeting GCS as an approach to treating drug resistance, in vivo. Aims 3 and 4 focus on mechanisms, and their outcomes will not detract from the possible therapeutic value of the study. This is the first study to investigate the influence of lipids on the multidrug-resistant phenotype. The results could lead to improved treatment of HIV/AIDS, malignant disorders, and bacterial and parasitic infectious diseases, as treatment of these diseases is classically hindered by drug resistance.

描述（由申请人提供）：该项目将使用体外癌细胞和体内肿瘤异种移植作为模型系统，确定神经酰胺、神经酰胺代谢物和葡萄糖神经酰胺合酶（GCS）对多重耐药表型表达的影响。 GCS 催化葡萄糖神经酰胺 (GC) 的形成，葡萄糖神经酰胺是高级糖脂（脑苷脂、神经节苷脂）的组成部分。 GC 等糖脂也是 ABC 转运蛋白的底物，其中 MDR1 蛋白、P-糖蛋白 (P-gp) 是其中的成员。细胞中 MDR1/P-gp 的过度表达是有效治疗许多传染性和恶性疾病的主要障碍。我们的目标是改善疾病的治疗。如果脂质参与 MDR1 表型的表达，那么在特定时刻阻断脂质代谢可能是限制多药耐药性的一种手段。许多药物——化疗药物、一氧化二氮、伽马射线——促进细胞神经酰胺的增加，从而引发细胞凋亡。然而，由于类脂底物酶的可用性增加，高水平的神经酰胺也会引发 GCS 的过度表达，从而导致 GC 水平升高。由于化疗药物和神经酰胺生成之间的关系，并且由于在多重耐药癌细胞和肿瘤中发现高水平的GC，我们假设脂质增强了多重耐药表型的表达。这种增强会减弱细胞对抗生素、抗肿瘤药物和艾滋病毒蛋白酶抑制剂的反应。本提案的目的是： 1. 确定GCS对MDR1/P-gp表达的影响； 2.确定GCS抑制剂PPMP调节GCS对体外多重耐药乳腺肿瘤异种移植模型中MDR1/P-gp表达和对阿霉素反应的影响； 3.确定脂质（神经酰胺、糖脂）对多药耐药表型表达的影响，4.确定化疗药物对GCS和MDR1表达的影响。我们已下令制定目标以促进原则证明的测试。目标 1 将使用体外模型展示靶向 GCS 作为限制 MDR1 表达的方法的力量。目标 2 将使用动物模型来评估靶向 GCS 作为治疗体内耐药性的方法的功效。目标 3 和 4 侧重于机制，其结果不会减损该研究可能的治疗价值。这是第一项研究脂质对多重耐药表型影响的研究。这些结果可能会改善艾滋病毒/艾滋病、恶性疾病以及细菌和寄生虫传染病的治疗，因为这些疾病的治疗通常会受到耐药性的阻碍。