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: 7774073
• 负责人: Myles C. Cabot
• 金额: $ 24.61万
• 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/7774073
• 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; P-Glycoproteins; 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; 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（申请人提供）：胰腺癌是最致命的癌症之一，死亡率接近100%。绝大多数胰腺癌发现得太晚而无法切除，并且对当前的化疗方案没有反应。由于手术通常无法起到治愈作用，因此胰腺癌的药物治疗一直是一个不断发展的探索领域。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是治疗胰腺癌的可行方法。一些药物，特别是与某些其他药物联合使用，通过刺激正常细胞蜡（称为神经酰胺）的过度产生来选择性杀死癌症。胰腺癌的这一研究领域尚未被探索。神经酰胺激活内在的细胞死亡级联，促进下游活性氧 (ROS) 的产生、半胱天冬酶活性、促凋亡 Bim（Bcl-2 相互作用死亡介质）的表达，并下调生存素。这些事件导致细胞凋亡、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。这些药物是芬维A胺 (4-HPR)（一种维生素 A 类似物）和 Valspodar (PCS 833)（一种环孢菌素 A 类似物）。这项研究将采用培养的人类胰腺癌细胞系和 SV-40 转化的永生化胰腺细胞系。总体假设是，胰腺癌细胞对神经酰胺非常敏感，该假设的推论是，增强神经酰胺的水平或神经酰胺的特定分子种类会沿着特定途径推动细胞毒性。这项研究有三个具体目标，旨在评估胰腺癌细胞对神经酰胺和神经酰胺控制的细胞死亡级联的脆弱性。具体目标 1 将使用 C6-神经酰胺（一种天然神经酰胺的短链、细胞可渗透类似物）来表征胰腺癌细胞对神经酰胺的反应，并确定引入阻断神经酰胺代谢的酶抑制剂是否会增强细胞毒性反应。具体目标 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。这里包括对二氢神经酰胺和响应 4-HPR 和 PSC 833 产生的神经酰胺进行质谱分析，以确定特定分子种类是否会引起特定反应，例如自噬和衰老。具体目标 3 将评估 4-HPR 和 PSC 833 产生的神经酰胺对与内在细胞死亡激活相关的生化事件的影响。这种方法的创新性在于可以操纵神经酰胺途径，为提高功效提供了一个现成的平台。胰腺癌现有疗法的疗效非常有限，而且治疗失败的发生率非常高，这是寻求新方法的有力理由。 公共健康相关性：该项目将通过研究无毒维生素 A 类似物 (4-HPR) 的影响来测试治疗胰腺癌的新方法。 4-HPR 可以通过刺激正常细胞蜡（称为神经酰胺）的过度产生来选择性杀死癌细胞，过量的神经酰胺对恶性细胞而非正常细胞是致命的。由于胰腺癌细胞可以将神经酰胺代谢为无毒副产物，因此我们将研究是否包含阻断神经酰胺代谢的“配合药物”，以便微调这种新的治疗方法。