Role of iNOS, Nitric Oxide & Arginase in Statin-Mediated Toxicity in Cancer Cells

iNOS（一氧化氮）的作用

• 批准号: 7934163
• 负责人: BALARAMAN KALYANARAMAN
• 金额: $ 8.51万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7934163
• 关键词: Acetyl Coenzyme A; Anabolism; Animal Model; Antineoplastic Agents; Antioxidants; Apoptosis; Apoptotic; Arginine; Benz(a)Anthracenes; Biological Assay; Blood Volume; Blood flow; Breast; Breast Cancer Cell; Bromides; Cancer cell line; Cancerous; Cardiovascular Diseases; Cardiovascular Physiology; Catabolism; Cause of Death; Cell Cycle Progression; Cell Death; Cell Proliferation; Cells; Chemoprevention; Chemopreventive Agent; Cholesterol; Citrulline; Clinical; Coenzyme A; Contrast Media; DNA Fragmentation; Development; Dose; Drug usage; Effectiveness; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Epithelial Cells; Farnesyl Transferase Inhibitor; Figs - dietary; Generations; Goals; Growth; High Pressure Liquid Chromatography; Human; Hydroxymethylglutaryl coenzyme A reductase; Hydroxymethylglutaryl-CoA reductase; Image; Imaging Techniques; Literature; MCF7 cell; Magnetic Resonance Imaging; Mammary Neoplasms; Mammary Tumorigenesis; Mammary gland; Measures; Mediating; Metabolic; Methods; Modeling; Molecular; Monitor; Monomeric GTP-Binding Proteins; Multiple Myeloma; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nutrient; Ornithine; Pharmaceutical Preparations; Polyamines; Postmenopause; Predisposition; Production; Protein Isoforms; Proteins; Rattus; Reaction; Relative (related person); Research; Role; Serum; Signal Transduction; Simvastatin; Small Interfering RNA; Squalene; Supplementation; Techniques; Testing; Thymidine; Time; Tocopherols; Tocotrienols; Toxic effect; Tumor Biology; Woman; arginase; base; benzanthracene; cancer cell; cancer therapy; cancer type; cell killing; cholesterol biosynthesis; cytotoxicity; farnesyl pyrophosphate; fluvastatin; geranylgeranyl pyrophosphate; human NOS2A protein; improved; in vivo; inhibitor/antagonist; innovation; killings; malignant breast neoplasm; mevalonate; mutant; neoplastic cell; overexpression; prenylation; prevent; protein geranylgeranyltransferase; research study; response; rho; sepiapterin; tetrahydrobiopterin; tumor; tumor growth; uptake

DESCRIPTION (provided by applicant): Long-term goal: Statins selectively inhibit the enzyme hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase leading to decreased cholesterol biosynthesis. Several natural and synthetic statins enhanced apoptosis in human lymphoblastoid, myeloma and breast cancer cells. This effect was directly related to their ability to inhibit HMG CoA reductase, which blocks the synthesis of isoprenylated small GTPases, and not by squalene, an immediate precursor of cholesterol. This proposal is based on the discovery that statins cause increased cytotoxicity to breast cancer cells through either increased expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) and/or decreased arginase expression. Statin-mediated cell death was partially reversed by 1400W, a more specific inhibitor of iNOS (NOS II), and by mevalonate, an immediate metabolic product of acetyl CoA/HMG-CoA reductase reaction. Mevalonate supplementation inhibited statin- induced iNOS and NO and restored arginase expression. Fluvastatin dose-dependently inhibited mammary tumor development in an in vivo animal model. Hypotheses to be tested are: (i) statins stimulate NO in breast cancer cells that is responsible for their proapoptotic, tumoricidal and antiproliferative effects, (ii) statins inhibit arginase expression and activity through inhibition of RhoA signaling in breast cancer cells, and (iii) supplementation with sepiapterin (iNOS co-factor) and tocotrienols potentiates statin-induced tumoricidal effects in breast cancer cells and in a rat model. Specific aims: (i) Assess the effects of various statins (lipophilic and hydrophilic) and tocotrienols on breast cancer cell proliferation, and apoptosis, (ii) Determine the induction of iNOS and NO formation in cells treated with statins alone and with sepiapterin and arginase inhibitors, (iii) Define the role of RhoA in statin-mediated NO generation, arginase expression, Nf:B inhibition and antiproliferative effects in breast cancer cells, (iv) Establish a chemopreventive rat model, and evaluate the effectiveness of statins alone and in combination with 3-tocotrienol or sepiapterin. Methods: We will use MCF- 7 and MDA-MB-231 cells and a chemically-induced breast cancer rat model. HPLC techniques will be used to detect and quantitate NO formation in cells treated with statins. Magnetic resonance imaging (MRI) will be used to assess the response to breast cancer therapy in a rat model. Significance: Recent research suggests that statins may prevent various types of cancers including breast cancer. However, the molecular mechanisms by which statins induce breast cancer cell death remain unknown. This proposal will advance our understanding of the chemopreventive and chemotherapeutic ability of statins, alone and in combination with naturally-occurring tocotrienols. Novelty: The overall goal is to elucidate the molecular mechanism by which statins exert antiproliferative/proapoptotic effects in breast cancer cells. The use of tocotrienols to synergistically enhance chemopreventive efficacy of statin in breast cancer cells and breast cancer animal model is innovative. MRI will be used to monitor chemopreventive effects of breast cancer in a rat model. PUBLIC HEARLTH RELEVANCE: Statins are one of the most widely prescribed group of drugs. Recent studies suggest that lipophilic statins may be beneficial for postmenopausal women. Studies also suggest that statins, when combined with other nutrients, become more potent as anticancer drugs. Breast cancer is the leading cause of death in women. Thus, it is both timely and important to understand the mechanism(s) by which statins kill breast cancer cells and to explore the possibility for clinical implementation of statins as chemopreventive drugs.

描述（由申请人提供）： 长期目标：他汀类药物选择性抑制羟甲基戊二酰辅酶 A (HMG-CoA) 还原酶，导致胆固醇生物合成减少。几种天然和合成的他汀类药物可增强人淋巴母细胞、骨髓瘤和乳腺癌细胞的凋亡。这种效应与它们抑制 HMG CoA 还原酶的能力直接相关，HMG CoA 还原酶会阻止异戊二烯化小 GTP 酶的合成，而不是与胆固醇的直接前体角鲨烯有关。该提议基于以下发现：他汀类药物通过增加诱导型一氧化氮合酶 (iNOS) 和一氧化氮 (NO) 的表达和/或减少精氨酸酶的表达，导致乳腺癌细胞的细胞毒性增加。他汀类药物介导的细胞死亡可被 1400W（一种更特异的 iNOS (NOS II) 抑制剂）和甲羟戊酸（乙酰 CoA/HMG-CoA 还原酶反应的直接代谢产物）部分逆转。补充甲羟戊酸可抑制他汀类药物诱导的 iNOS 和 NO，并恢复精氨酸酶的表达。在体内动物模型中，氟伐他汀剂量依赖性地抑制乳腺肿瘤的发展。要测试的假设是：(i) 他汀类药物刺激乳腺癌细胞中的 NO，从而产生促凋亡、杀肿瘤和抗增殖作用，(ii) 他汀类药物通过抑制乳腺癌细胞中的 RhoA 信号传导来抑制精氨酸酶的表达和活性，以及​​ (iii) 补充墨蝶呤（iNOS 辅因子）和生育三烯酚可增强他汀类药物诱导的精氨酸酶表达和活性。 对乳腺癌细胞和大鼠模型的杀肿瘤作用。具体目标：(i) 评估各种他汀类药物（亲脂性和亲水性）和生育三烯酚对乳腺癌细胞增殖和凋亡的影响，(ii) 确定单独使用他汀类药物以及使用墨蝶呤和精氨酸酶抑制剂处理的细胞中诱导 iNOS 和 NO 形成的情况，(iii) 确定 RhoA 在他汀类药物介导的 NO 生成、精氨酸酶表达、Nf:B 中的作用 对乳腺癌细胞的抑制和抗增殖作用，(iv)建立化学预防大鼠模型，并评估他汀类药物单独使用以及与3-生育三烯酚或墨蝶呤联合使用的有效性。方法：我们将使用 MCF-7 和 MDA-MB-231 细胞以及化学诱导的乳腺癌大鼠模型。 HPLC 技术将用于检测和定量他汀类药物处理的细胞中 NO 的形成。磁共振成像（MRI）将用于评估大鼠模型对乳腺癌治疗的反应。意义：最近的研究表明他汀类药物可以预防包括乳腺癌在内的各种类型的癌症。然而，他汀类药物诱导乳腺癌细胞死亡的分子机制仍不清楚。该提案将增进我们对他汀类药物单独使用以及与天然生育三烯酚联合使用的化学预防和化疗能力的理解。新颖性：总体目标是阐明他汀类药物在乳腺癌细胞中发挥抗增殖/促凋亡作用的分子机制。使用生育三烯酚协同增强他汀类药物对乳腺癌细胞和乳腺癌动物模型的化学预防功效是创新的。 MRI 将用于监测大鼠模型中乳腺癌的化学预防作用。公众健康相关性：他汀类药物是最广泛使用的药物之一。最近的研究表明，亲脂性他汀类药物可能对绝经后妇女有益。研究还表明，他汀类药物与其他营养素结合使用时，作为抗癌药物会变得更有效。乳腺癌是女性死亡的主要原因。因此，了解他汀类药物杀伤乳腺癌细胞的机制，探讨他汀类药物作为化学预防药物临床应用的可能性，是及时且重要的。