Ceramide, Membrane Glycolipids and Glycoprotein Expression

神经酰胺、膜糖脂和糖蛋白表达

• 批准号: 7682746
• 负责人: Myles C. Cabot
• 金额: $ 4.32万
• 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/7682746
• 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(申请人提供)：该项目将以体外癌细胞和体内肿瘤异种照相为模型系统，确定神经酰胺、神经酰胺代谢物和葡萄糖神经酰胺合成酶(GCS)对多药耐药表型表达的影响。GCS催化葡萄糖神经酰胺(GC)的形成，这是高级糖脂(脑苷脂、神经节苷脂)的组成部分。糖脂如GC也是ABC转运蛋白的底物，MDR1蛋白，P-糖蛋白(P-gp)是其中的一员。MDR1/P-gp在细胞中的过度表达是许多感染性和恶性疾病有效治疗的主要障碍。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，那么在特定的结合点阻断脂代谢可能是限制多药耐药的一种手段。许多药物--化疗药物、一氧化二氮、伽玛射线--都会促进细胞神经酰胺的增加，从而导致细胞凋亡。然而，高水平的神经酰胺也可以触发GCS的过度表达，这是由于酶类脂底物的可用性增加，导致GC水平升高。由于化疗药物与神经酰胺生成的关系，以及在多药耐药癌细胞和肿瘤中发现高水平的GC，我们假设脂类促进了多药耐药表型的表达。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。本研究的目的是：1.确定GCS对mdr1/P-gp表达的影响；2.确定GCS抑制剂PPMP对mdr1/P-gp表达的影响以及体外多药耐药乳腺肿瘤移植瘤模型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。我们已经下令了AIMS，以便利原则证明的测试。目的1将使用体外模型证明靶向GCS作为限制mdr1表达的方法的能力。目的2，使用动物模型，在体内评估靶向GCS作为治疗耐药性的方法的能力。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。这是第一次研究脂类对多药耐药表型的影响。这一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受到耐药性的阻碍。