Fatty Acid Synthase:Molecular Target for Breast Cancer Therapy & Chemoprevention

脂肪酸合成酶：乳腺癌治疗的分子靶点

• 批准号: 7476258
• 负责人: RUTH LUPU
• 金额: $ 7.05万
• 依托单位: NORTHSHORE UNIVERSITY HEALTHSYSTEM
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-16 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7476258
• 关键词: Accounting; Acidity; Address; Affect; Anabolism; Angiogenic Factor; Animals; Anthracycline Antibiotics; Anthracyclines; Apoptosis; Attenuated; Behavior; Biogenesis; Biological Assay; Biopsy; Breast; Breast Cancer Cell; Breast Cancer Model; Breast Cancer Treatment; Breast Carcinoma; Cancer Etiology; Cancer Patient; Cancer cell line; Carcinoma; Cell Death; Cell membrane; Cell model; Cells; Cerulenin; Chemicals; Chemoprevention; Clinical; Code; Commit; Complex; Cultured Cells; Cytotoxic agent; Data; Development; Diagnosis; Diagnostic Neoplasm Staging; Diet; Dietary Fatty Acid; Disease; Down-Regulation; Drug resistance; Early Intervention; Employee Strikes; Engineering; Epigenetic Process; Epithelial; Epithelial Cells; Equilibrium; Event; Evolution; Exhibits; Exposure to; Extracellular Domain; Fatty Acids; Fatty acid glycerol esters; Fatty-acid synthase; Fibroblasts; Gene Amplification; Gene Expression; Gene Expression Profiling; Gene Targeting; Genes; Growth; Human; Hyperactive behavior; Hypersensitivity; Hypoxia; Immunotherapy; Impairment; In Vitro; Incubated; Inhibition of Apoptosis; Invasive; Laboratories; Lesion; Link; Lipids; MEKs; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mammary Neoplasms; Measurement; Mediating; Membrane; Messenger RNA; Metabolic; Minor; Modification; Molecular; Molecular Target; Mus; Mycotoxins; Nature; Neoplasm Metastasis; Neoplastic Cell Transformation; Noninfiltrating Intraductal Carcinoma; Normal Cell; Normal tissue morphology; Obesity; Oleic Acid; Oleic Acids; Oncogene Proteins; Oncogenes; Oncogenic; P-Glycoprotein; P-Glycoproteins; PEA3; PI3K/AKT; Pathway interactions; Pharmacologic Substance; Phase; Phenotype; Physiological; Play; Population Study; Predictive Value; Premalignant; Prevention; Protein Overexpression; Protein Tyrosine Kinase; Proteins; Proteomics; RNA Interference; Ras/Raf; Rate; Receptor Protein-Tyrosine Kinases; Regulation; Relative (related person); Reporting; Research; Research Personnel; Resistance; Risk; Roche brand of trastuzumab; Role; Score; Serum; Signal Transduction; Small Interfering RNA; Small RNA; Solid Neoplasm; Source; Staging; Stream; Testing; Therapeutic; Tissues; Transcriptional Activation; Transfection; Trastuzumab; Treatment Protocols; Tumorigenicity; Up-Regulation; Vascular Endothelial Growth Factors; Vinorelbine; angiogenesis; base; breast lesion; cancer cell; cancer risk; cancer therapy; cell growth; cell injury; cell killing; cellular engineering; chemotherapy; clinically relevant; cytotoxicity; docetaxel; fatty acid biosynthesis; gene repression; hormone therapy; humanized monoclonal antibodies; hypoxia inducible factor 1; in vivo; inhibitor/antagonist; lipid biosynthesis; lobular breast carcinoma in situ; malignant breast neoplasm; malignant phenotype; neoplastic; neoplastic cell; novel; novel therapeutics; orlistat; outcome forecast; prognostic; promoter; prospective; response; sensor; therapeutic target; transcription factor; tumor; tumor progression

DESCRIPTION (provided by applicant): There are two sources of fatty acids for animals, exogenous (dietary) fatty acids and de novo endogenous biosynthesis, of which the latter is regulated by Fatty Acid Synthase (FAS). The high level of fat in the Western diet has been implicated in the development of many human malignancies, including breast cancer. Indeed, dietary fatty acids have emerged as an intense focus of research and controversy in breast cancer etiology, prevention and/or therapy. Human breast cancer cell lines and breast tumors exhibit overexpression and hyperactivity of FAS, with FAS-overexpressing breast cancer tumors demonstrating shortened disease-free intervals or overall survivals. Moreover, FAS overexpression can also be identified in intraductal and lobular in situ breast carcinoma, pre-neoplastic lesions associated with increased risk for the development of infiltrating breast cancer, while elevated serum FAS levels have been identified in breast cancer patients with different clinical stages compared with healthy subjects. Interestingly, the relative absence of endogenous fatty acid biosynthesis in normal tissues has led to the notion that FAS blockade should provide a highly selective basis for anticancer therapy. These data, altogether, reveal that FAS-dependent de novo fatty biogenesis, an anabolic energy-storage pathway largely considered of minor importance in humans, may ultimately be used for diagnosis, prognosis, early intervention, and treatment of breast carcinomas. As a part of our efforts to assess the role of FAS signaling on the survival and proliferation of human breast cancer cells, we have identified a novel bi-directional molecular link between breast cancer-associated FAS and Her-2/neu oncogene. A positive correlation was found between high levels of FAS expression and the amplification and/or overexpression of Her-2/neu oncogene. Pharmacological inhibition of FAS by the natural mycotoxin cerulenin, or a related synthetic compound, C75 or a statin Orlistat, negatively regulated Her-2/neu-encoded p185Her-2/neu oncoprotein and its associated tyrosine-kinase activity. When FAS gene expression was silenced by RNA interference (RNAi) a dramatic decrease of p185Her-2/neu expression occurred in the Her-2/neu-overexpressing cells, whereas there was no effect in cells expressing physiological levels of Her-2/neu. Remarkably, pharmacological and RNAi mediated downregulation of Her-2/neu and, concomitantly, caused a prominent up-regulation of PEA3, a transcriptional represser of Her-2/neu. Furthermore, a simultaneous targeting of FAS and Her-2/neu signaling by chemical FAS inhibitors and the humanized monoclonal antibody directed against p185Her-2/neu trastuzumab (Herceptin(tm)), resulted in a synergistic growth inhibitory effect towards Her-2/neu overexpressing cells. These findings support the hypothesis that breast cancer-associated FAS, rather than simply the epigenetic consequence of aberrant activation of up-stream transduction pathways (e.g. PI-3K/AKT, Ras/Raf/MEK/ERK) plays an active role in breast cancer evolution by regulating oncogenic proteins closely related to malignant transformation. Indeed, our pioneer observations demonstrating the ability of FAS-driven signaling to regulate the expression and/or activity of Her-2/neu (erbB-2) oncogene strongly suggest that FAS may actively participate in the triggering, maintenance and/or enhancement of the breast cancer malignant phenotype. Therefore our aims are: 1) To characterize the molecular mechanism determining the early up-regulation of FAS in breast cancer and to evaluate the oncogenic potential of FAS-catalyzed endogenous lipogenesis in normal breast epithelial cell models. We will determine how FAS contributes to the pre-neoplastic transformation of noncommittal breast epithelial cells (normal cells) and whether FAS overexpression sets off malignant transformation. 2) To evaluate the therapeutic relevance of targeting FAS in Her-2/neu-overexpressing breast cancer in vitro and in vivo on the basis of the novel bidirectional molecular link between FAS and the Her-2/neu that we recently demonstrated. 3) We will characterize the molecular mechanisms underlying the bi-directional molecular cross-talk between FAS and Her-2/neu. In addition, we will assess whether FAS blockade represents a novel sensitizing strategy to reverse trastuzumab (Herceptin(tm)) resistance in Her-2/neu-overexpressing breast carcinomas. 4) To evaluate whether inhibition of FAS activity modulates breast cancer cell sensitivity to chemotherapy-induced cell damage and to evaluate whether silencing FAS expression modulates breast cancer cell sensitivity to chemotherapy-induced cell damage. 5) To determine the molecular relevance and clinical impact of FAS expression in breast cancer progression, and to evaluate the value and clinical contribution to the treatment decision provided by the assessment of circulating serum levels of FAS. Our study speculates that constitutive up-regulation of FAS in breast cancer disease represents an early metabolic response for survival to the hypoxic and acidic microenvironment of pre-malignant breast cancer phases. This epigenetic up-regulation of FAS in early stages of breast cancer may result, in turn, in a metabolic strategy of selection to maintain high proliferation rates of surviving cells. The characterization of FAS as a novel metabolic oncogene will allow an invaluable adjunct to gene expression profiling or proteomics in the characterization of biologically aggressive subsets of breast carcinomas. Moreover, the predictive potential of measurement FAS expression will help in the selection of better responders to cytotoxic drugs, and Her-2/neu-targeted therapies. Considering that drug resistance hampers successful breast cancer treatment, and its prevention or reversal is still awaiting new sensitizing strategies or pharmaceuticals, our study will open a new molecular avenue based on the specific targeting of FAS-dependent neoplastic lipogenesis, a valuable specific molecular target that is minimally activated in normal tissues.

描述（由申请人提供）：动物脂肪酸有两种来源，外源性（膳食）脂肪酸和新生内源性生物合成脂肪酸，后者由脂肪酸合成酶（FAS）调节。西方饮食中的高脂肪含量与许多人类恶性肿瘤的发展有关，包括乳腺癌。事实上，膳食脂肪酸已经成为乳腺癌病因学、预防和/或治疗研究和争议的焦点。人类乳腺癌细胞系和乳腺肿瘤表现出FAS的过表达和过活跃，FAS过表达的乳腺癌肿瘤表现出较短的无病间隔或总生存期。此外，在导管内和小叶原位乳腺癌中也可以发现FAS过表达，这些肿瘤前病变与浸润性乳腺癌的发展风险增加有关，而在不同临床阶段的乳腺癌患者中，与健康受试者相比，血清FAS水平升高。有趣的是，正常组织中内源性脂肪酸生物合成的相对缺乏导致了FAS阻断应该为抗癌治疗提供高度选择性基础的概念。综上所述，这些数据揭示了fas依赖性的新生脂肪生物生成，一种在人类中被认为不太重要的合成代谢能量储存途径，最终可能用于乳腺癌的诊断、预后、早期干预和治疗。作为我们努力评估FAS信号在人类乳腺癌细胞存活和增殖中的作用的一部分，我们已经确定了乳腺癌相关FAS和Her-2/neu癌基因之间的一种新的双向分子联系。FAS的高水平表达与Her-2/neu癌基因的扩增和/或过表达呈正相关。天然真菌毒素cerulenin或相关合成化合物C75或他汀类奥利listat对FAS的药理学抑制可负性调节Her-2/neu编码的p185Her-2/neu癌蛋白及其相关酪氨酸激酶活性。当RNA干扰（RNAi）抑制FAS基因表达时，过表达Her-2/neu的细胞中p185Her-2/neu的表达显著降低，而对表达Her-2/neu生理水平的细胞无影响。值得注意的是，药理学和RNAi介导Her-2/neu的下调，并同时引起Her-2/neu的转录抑制因子PEA3的显著上调。此外，FAS化学抑制剂和靶向p185Her-2/neu曲妥珠单抗（Herceptin(tm)）的人源化单克隆抗体同时靶向FAS和Her-2/neu信号传导，对Her-2/neu过表达细胞产生协同生长抑制作用。这些发现支持了一种假设，即乳腺癌相关FAS，而不仅仅是上游转导通路（如PI-3K/AKT， Ras/Raf/MEK/ERK）异常激活的表观遗传后果，通过调节与恶性转化密切相关的致癌蛋白，在乳腺癌进化中发挥积极作用。事实上，我们的先驱观察表明，FAS驱动的信号能够调节Her-2/neu （erbB-2）癌基因的表达和/或活性，这强烈表明FAS可能积极参与乳腺癌恶性表型的触发、维持和/或增强。因此，我们的目标是：1)确定FAS在乳腺癌中早期上调的分子机制，并在正常乳腺上皮细胞模型中评估FAS催化的内源性脂肪生成的致癌潜力。我们将确定FAS如何促进非浸润性乳腺上皮细胞（正常细胞）的癌前转化，以及FAS过表达是否会引发恶性转化。2)基于我们最近证明的FAS与Her-2/neu之间新的双向分子联系，在体外和体内评估靶向FAS治疗Her-2/neu过表达乳腺癌的治疗相关性。3)我们将描述FAS和Her-2/neu之间双向分子串扰的分子机制。此外，我们将评估FAS阻断是否代表一种新的增敏策略，以逆转Her-2/ new -过表达乳腺癌中曲妥珠单抗（赫赛汀）的耐药。4)评价FAS活性的抑制是否能调节乳腺癌细胞对化疗诱导的细胞损伤的敏感性，以及FAS表达沉默是否能调节乳腺癌细胞对化疗诱导的细胞损伤的敏感性。5)探讨FAS表达在乳腺癌进展中的分子相关性及临床影响，评价血清循环FAS水平评估对治疗决策的价值及临床贡献。我们的研究推测，乳腺癌疾病中FAS的组成性上调代表了恶性乳腺癌前期缺氧和酸性微环境下生存的早期代谢反应。乳腺癌早期FAS的表观遗传上调可能反过来导致维持存活细胞高增殖率的代谢选择策略。FAS作为一种新的代谢性癌基因的特性将为乳腺癌生物侵袭性亚群的基因表达谱或蛋白质组学特性提供宝贵的辅助手段。此外，测定FAS表达的预测潜力将有助于选择对细胞毒性药物和Her-2/新靶向治疗有更好反应的患者。考虑到耐药阻碍了乳腺癌的成功治疗，其预防或逆转仍在等待新的致敏策略或药物，我们的研究将开辟一个新的分子途径，基于特异性靶向fas依赖性肿瘤脂肪生成，这是一个有价值的特异性分子靶点，在正常组织中被最低限度地激活。