Novel Ceramide-based Chemotherapy for Acute Leukemia

治疗急性白血病的新型神经酰胺化疗

• 批准号: 6823787
• 负责人: BARRY J MAURER
• 金额: $ 24.98万
• 依托单位: CHILDREN'S HOSPITAL OF LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-10 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6823787
• 关键词: RNA; acute leukemia; antineoplastics; antisense nucleic acid; cell line; ceramides; clinical research; combination chemotherapy; cytotoxicity; drug interactions; fenretinide; high performance liquid chromatography; human subject; laboratory mouse; lipid metabolism; meperidine; neoplasm /cancer chemotherapy; neoplasm /cancer pharmacology; neoplastic cell; patient oriented research; pharmacokinetics; small interfering RNA; sphingosine; stereoisomer; transfection; xenotransplantation

DESCRIPTION (provided by applicant): Our goal is to establish a p53-independent chemotherapy for ALL leukemias based upon the intracellular generation and manipulation of the pro-death lipid, ceramide. We reported that fenretinide (4-HPR) increased de novo ceramide synthesis in cancer cell lines in vitro, and inhibitors of ceramide catabolism, such as safingol and PPMP, synergistically increased 4-HPR cytotoxicity. We have developed formulations 4-HPR and safingol for clinical testing. We hypothesize that combinations of 4-HPR, safingol, and PPMP, will have anti-leukemia activity with tolerable systemic toxicity in vivo, and that defining the mechanisms of 4-HPR synergy in ALL cell lines will facilitate clinical development. AIM 1. Define the molecular mechanisms of 4-HPR cytotoxicity. A) Determine the dependence of 4-HPR cytotoxicity and synergy upon de novo ceramide by abrogating de novo ceramide synthesis using antisense and siRNA to the LCB1 subunit of SPT. B) Determine the molecular ordering of 4-HPR cytotoxicity by measuring ceramide, ROS, mitochondrial membrane potential (psi/m), cytochrome c release, and caspase activation, in parental and mitochondrial DNA-deficient (Rho) cell derivatives. AIM 2. Determine the active metabolite of safingol and its effect on 4-HPR-induced de novo ceramide catabolism. Determine the kinetics of 3H-safingol and catabolites, and effects on ceramide, sphingosine, and sphingosine kinase. Determine if L-threo-dihydroceramides or L-threo-ceramides reproduce the effects of safingol. AIM 3. Determine the effect of inhibiting acylceramide synthase (ACS) and glucosylceramide synthase (GCS) on 4-HPR cytotoxicity. Identify a preferred stereoisomer of PPMP. ACS and GCS catabolize de novo ceramide to nontoxic products. Determine the effect on 4-HPR cytotoxicity of selectively inhibiting ACS and GCS with antisense and/or siRNA. Identify an isomer of PPMP to inhibit both ACS and GCS. AIM 4. Establish the pharmacokinetic and pharmacodynamic interactions of 4-HPR, safingol, and PPMP in an ALL cells xenograft model. Correlate fenretinide and PPMP levels assayed by HPLC with ceramide levels assayed by mass spectroscopy in xenografts. Use drug and ceramide levels, xenograft response, and animal systemic toxicity to optimize delivery of 4-HPR, safingol, and PPMP.

描述（由申请人提供）：我们的目标是基于促死亡脂质神经酰胺的细胞内生成和操作，为所有白血病建立一种不依赖于 p53 的化疗。我们报道，芬维A胺（4-HPR）在体外增加了癌细胞系中神经酰胺的从头合成，而神经酰胺分解代谢抑制剂，如safingol和PPMP，协同增加了4-HPR的细胞毒性。我们开发了用于临床测试的 4-HPR 和 safingol 制剂。我们假设 4-HPR、safingol 和 PPMP 的组合将具有抗白血病活性，并具有可耐受的体内全身毒性，并且确定 4-HPR 在 ALL 细胞系中协同作用的机制将有助于临床开发。目的 1. 明确 4-HPR 细胞毒性的分子机制。 A) 通过使用 SPT 的 LCB1 亚基的反义和 siRNA 消除从头神经酰胺合成，确定 4-HPR 细胞毒性和协同作用对从头神经酰胺的依赖性。 B) 通过测量亲本和线粒体 DNA 缺陷 (Rho) 细胞衍生物中的神经酰胺、ROS、线粒体膜电位 (psi/m)、细胞色素 c 释放和 caspase 激活来确定 4-HPR 细胞毒性的分子顺序。目的 2. 确定 safingol 的活性代谢物及其对 4-HPR 诱导的神经酰胺从头分解代谢的影响。确定 3H-safingol 和分解代谢物的动力学，以及对神经酰胺、鞘氨醇和鞘氨醇激酶的影响。确定 L-苏型二氢神经酰胺或 L-苏型神经酰胺是否能重现 safingol 的作用。目的3.确定抑制酰基神经酰胺合酶(ACS)和葡萄糖神经酰胺合酶(GCS)对4-HPR细胞毒性的影响。确定 PPMP 的首选立体异构体。 ACS 和 GCS 将神经酰胺从头分解代谢为无毒产品。确定用反义和/或 siRNA 选择性抑制 ACS 和 GCS 对 4-HPR 细胞毒性的影响。鉴定 PPMP 的异构体以抑制 ACS 和 GCS。目的 4. 在 ALL 细胞异种移植模型中建立 4-HPR、safingol 和 PPMP 的药代动力学和药效学相互作用。将 HPLC 测定的芬维A胺和 PPMP 水平与异种移植物中质谱测定的神经酰胺水平相关联。利用药物和神经酰胺水平、异种移植反应和动物全身毒性来优化 4-HPR、safingol 和 PPMP 的递送。