Assessing pancreatic cancer susceptibility to ceramide-mediated cell death.

评估胰腺癌对神经酰胺介导的细胞死亡的敏感性。

• 批准号: 8010219
• 负责人: Myles C. Cabot
• 金额: $ 19.9万
• 依托单位: SAINT JOHN'S CANCER INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8010219
• 关键词: Apoptosis; Apoptotic; Area; Autophagocytosis; Biochemical; Cancer Biology; Cancer cell line; Caspase; Cell Aging; Cell Death; Cell Line; Cell Survival; Cells; Ceramides; Cessation of life; Clinical Trials; Cyclosporine; Data; Development; Disease; Down-Regulation; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Event; Fenretinide; Generations; Genes; Goals; Human; Human Cell Line; Hydrolysis; Incidence; Investigation; Knowledge; Lead; Link; MAPK8 gene; Malignant Neoplasms; Malignant neoplasm of pancreas; Mass Spectrum Analysis; Mediating; Mediator of activation protein; Medical; Metabolic Pathway; Metabolism; Mitochondria; Mitogen-Activated Protein Kinases; Molecular; Multi-Drug Resistance; N-caproylsphingosine; Nature; Normal Cell; Operative Surgical Procedures; P-Glycoprotein; Pancreas; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Pilot Projects; Predisposition; Process; Production; Reactive Oxygen Species; Regimen; Resected; Role; Route; Scheme; Signal Transduction; Sphingomyelins; Testing; Treatment Failure; Valspodar; Waxes; analog; anti-cancer therapeutic; apoptosis inducing factor; cancer cell; caspase-3; clinical efficacy; cytochrome c; cytotoxic; cytotoxicity; design; dihydroceramide; glycosylation; improved; innovation; killings; molecular marker; mortality; novel; novel strategies; pancreatic cancer cells; public health relevance; research study; response; senescence; survivin; vitamin A analog

DESCRIPTION (provided by applicant): Pancreatic cancer is one of the deadliest cancers, with a mortality rate of nearly 100%. The vast majority of pancreatic cancers are discovered too late to resect and do not respond to current chemotherapeutic regimens. Because surgery generally has little to offer curatively, medical management of pancreatic cancer has been a growing area of exploration. The long-term objective of this R21 pilot project application is to determine whether the use of agents that enhance cellular ceramide levels will be a viable approach for treating pancreatic cancer. Some drugs, especially in combination with certain other drugs, selectively kill cancers by stimulating over-production of normal cellular waxes known as ceramides. This area of investigation in pancreatic cancer is unexplored. Ceramides activate intrinsic cell death cascades that promote downstream generation of reactive oxygen species (ROS), caspase activity, expression of proapoptotic Bim (Bcl-2-interacting mediator of death), and downregulate survivin. These events contribute to apoptosis, autophagy, and cellular senescence. To determine whether targeting ceramide metabolism is an effective avenue for treating pancreatic cancer, two agents that promote ceramide formation in pancreatic cancer cells will be studied. These agents are fenretinide (4-HPR), a vitamin A analog, and Valspodar (PCS 833), a cyclosporin A analog. This study will employ cultured human pancreatic cancer cell lines and an SV-40- transformed, immortalized pancreatic cell line. The overall hypothesis is that pancreatic cancer cells are acutely sensitive to ceramide with the corollary to this hypothesis being that enhancing either the level of ceramide or specific molecular species of ceramide propels cytotoxicity along specific routes. This study has three specific aims designed to assess pancreatic cancer cell vulnerability to ceramide and ceramide-governed cell death cascades. Specific Aim 1 will characterize pancreatic cancer cell response to ceramide by using C6- ceramide, a short-chain, cell permeable analog of natural ceramide, and determine if cytotoxic responses are enhanced by the introduction of enzyme inhibitors that block ceramide metabolism. Specific Aim 2 will characterize the effect of 4-HPR and PSC 833 on cell viability and determine if cytotoxicity is linked to ceramide. Included here are mass spectroscopic analysis of dihydroceramides and ceramides generated in response to 4-HPR and PSC 833 to determine whether specific molecular species provoke specific responses, autophagy and senescence for example. Specific Aim 3 will assess the influence of ceramide generated in response to 4-HPR and PSC 833 on biochemical events associated with activation of intrinsic cell death. The innovative nature of this approach is that ceramide pathways can be manipulated, presenting a ready platform to improve efficacy. The very limited efficacy of available therapies for pancreatic cancer and the very high incidence of treatment failure are strong reasons to pursue new approaches. PUBLIC HEALTH RELEVANCE: This project will test a new approach to treat pancreatic cancer by studying the influence of a non-toxic vitamin A analog (4-HPR). 4-HPR can selectively kill cancer cells by stimulating over-production of normal cell waxes, called ceramides, which in excess are lethal to malignant cells and not normal cells. Because pancreatic cancer cells can metabolize ceramide to non-toxic byproducts, we will investigate inclusion of "partnering drugs" that block ceramide metabolism in order to fine-tune this novel approach to therapy.

描述（由申请人提供）：胰腺癌是最致命的癌症之一，死亡率接近100％。绝大多数胰腺癌被发现为时已晚，无法切除并且不对当前的化学治疗方案做出反应。由于手术通常几乎没有经过待遇，因此胰腺癌的医疗管理一直是越来越多的勘探领域。该R21试点项目应用的长期目标是确定使用增强细胞神经酰胺水平的药物是否将是治疗胰腺癌的可行方法。一些药物，尤其是与某些其他药物结合使用，通过刺激过量生产称为神经酰胺的正常细胞蜡来有选择地杀死癌症。胰腺癌研究领域尚未探索。神经酰胺激活了固有的细胞死亡级联反应，从而促进了活性氧（ROS），caspase活性，促凋亡BIM的表达（Bcl-2相互作用的死亡介体）和下调Survivin。这些事件有助于凋亡，自噬和细胞衰老。为了确定靶向神经酰胺代谢是否是治疗胰腺癌的有效途径，将研究两种促进胰腺癌细胞中神经酰胺形成的药物。这些药物是富氏素（4-HPR），一种类似物的维生素A和Valspodar（PCS 833），一种类似物的环孢菌素。这项研究将采用培养的人胰腺癌细胞系和SV-40转化的永生胰腺细胞系。总体假设是，胰腺癌细胞对神经酰胺敏锐敏感，并为此假设敏感，因为该假设增强了神经酰胺或特定神经酰胺促进沿特定路线的细胞毒性的水平。这项研究具有三个特定的目的，旨在评估胰腺癌细胞脆弱性与神经酰胺和治疗胺的细胞死亡级联反应。特定的目标1将通过使用C6-神经酰胺，短链，天然神经酰胺的细胞渗透类似物来表征胰腺癌细胞对神经酰胺的反应，并通过引入阻断神经酰胺代谢的酶抑制剂来确定细胞毒性反应是否得到增强。特定的目标2将表征4-HPR和PSC 833对细胞活力的影响，并确定细胞毒性是否与神经酰胺有关。这里包括对4-HPR和PSC 833产生的二氢氧酰胺和神经酰胺的质谱分析，以确定特定的分子物种是否会引起特定的反应，自噬和衰老。具体目标3将评估对4-HPR和PSC 833响应的神经酰胺对与固有细胞死亡激活相关的生化事件的影响。这种方法的创新性质是可以操纵神经酰胺的途径，并提供了提高功效的现成平台。可用疗法的胰腺癌疗法的功效非常有限，治疗失败的发生率很高，这是采用新方法的强烈理由。 公共卫生相关性：该项目将通过研究非毒性维生素A类似物的影响（4-HPR）来测试一种治疗胰腺癌的新方法。 4-HPR可以通过刺激过量生产正常细胞蜡（称为神经酰胺）来选择性地杀死癌细胞，而正常细胞蜡对恶性细胞而不是正常细胞是致命的。由于胰腺癌细胞可以将神经酰胺代谢为无毒的副产品，因此我们将研究纳入“伴侣药物”，以阻止神经酰胺代谢，以微调这种新颖的治疗方法。