Targeted Therapeutics of LGL Leukemia utilizing Ceramide Nanoliposomes

描述(申请人提供)：本申请的长期目标是设计、开发和优化下一代聚乙二醇化C6-神经酰胺阳离子脂质体配方，用于治疗大颗粒淋巴细胞(LGL)白血病。LGL白血病是由T细胞或自然杀伤(NK)细胞的克隆性增殖引起的。目前还没有已知的治疗LGL白血病的方法。白血病LGL抵抗Fas诱导的细胞凋亡，并表现出高水平的激活的STAT3，这是致癌信号的关键介质。抑制白血病LGL中的STAT3会导致生存蛋白Mcl-1的减少，并增加对Fas介导的细胞凋亡的敏感性。这一应用的基础是第一代C6-神经酰胺纳米脂质体，它已被国家癌症研究所纳米技术表征实验室采用为平台技术。具体目标集中在中心假设上，即纳米级、非聚集的C6-神经酰胺脂质体为系统靶向LGL白血病细胞的疏水化疗药物和/或siRNA提供了高度敏感、选择性、无毒、隐形、可生物降解和响应的平台。多功能纳米脂质体旨在提供神经酰胺(C6神经酰胺)的细胞渗透性类似物以及靶向特异性siRNA和/或甲氨蝶呤，将在LGL白血病的Fischer F344大鼠模型中进行测试。假设同时给予甲氨蝶呤和/或siRNA的神经酰胺脂质体对LGL白血病有协同疗效。第一个具体目标将在已建立的动物模型中检验脂质体短链神经酰胺全身给药抑制LGL白血病的假设。特殊目的2将验证这样的假设，即聚乙二醇化的阳离子脂质体可以在体外和体内将抑制性siRNA和化疗药物输送到LGL白血病细胞，从而增强它们的抗白血病活性。特异靶3将验证一种假设，即与LGL白血病的特异性标志物CD8的单抗偶联，将在体外和体内将治疗性脂质体靶向LGL白血病细胞。特定目标3的实验是通过靶向癌细胞表达的表面抗原来传递免疫脂质体的重要原则验证研究。本申请中概述的这种第二代癌症纳米技术平台的开发具有改进癌症治疗的潜力。 公共卫生相关性这项应用的目标是利用一种新的癌症纳米技术平台开发大颗粒淋巴细胞(LGL)白血病的治疗方法。我们建议将系统靶向的C6-神经酰胺阳离子纳米免疫脂质体制剂包裹甲氨蝶呤和siRNAs应用于已建立的LGL白血病动物模型。这些研究将为在患有这种不治之症的人类受试者中使用这种治疗方法提供基础。

DESCRIPTION (provided by applicant): The broad long term goal of this application is to design, develop and optimize the next-generation of pegylated C6-ceramide cationic liposomal formulations for treatment of large granular lymphocyte (LGL) leukemia. LGL leukemia arises from clonal proliferation of either T cells or natural killer (NK) cells. There is no known curative therapy for patients with LGL leukemia. Leukemic LGL are resistant to Fas-induced apoptosis and display high levels of activated STAT3, a critical mediator of oncogenic signaling. Inhibition of STAT3 in leukemic LGL causes a decrease in survival protein Mcl-1 and an increased sensitivity to Fas-mediated apoptosis. The foundation of this application is a first generation C6-ceramide nanoliposome which has been adopted as platform technology by the Nanotechnology Characterization Laboratory of the National Cancer Institute. The specific aims are focused around the central hypothesis that nano-scale, non- aggregating C6-ceramide liposomes offer exquisitely sensitive, selective, non-toxic, stealthy, biodegradable and responsive platforms for systemically targeting hydrophobic chemotherapeutic drugs and/or siRNA to LGL leukemic cells. The potential clinical usefulness of multi-functional nanoliposomes, designed to deliver cell-permeable analogs of ceramide (C6 ceramide) as well as target-specific siRNA and/or Methotrexate, will be tested in a Fischer F344 rat model of LGL leukemia. It is hypothesized that simultaneous delivery of Methotrexate and/or siRNA in a ceramide-incorporated liposome will have synergistic efficacy in LGL leukemia. The first specific Aim will test the hypothesis that systemic delivery of liposomal short-chain ceramide inhibits LGL leukemia in an established animal model. Specific Aim 2 will test the hypothesis that the pegylated cationic liposomes allow delivery of inhibitory siRNA and chemotherapeutic drugs into LGL leukemic cells in vitro and in vivo, such that their anti-leukemic activity is enhanced. Specific Aim 3 will test the hypothesis that conjugation of a monoclonal antibody to CD8, the specific marker for LGL leukemia, will target the therapeutic liposomes to LGL leukemic cells in vitro and in vivo. Experiments in specific aim 3 are important proof-of-principle studies for delivery of immunoliposomes by targeting surface antigens expressed on cancer cells. Development of this second generation cancer nanotechnology platform as outlined in this application has potential for improved cancer therapeutics. PUBLIC HEALTH RELEVANCE The goal of this application is to develop therapy for large granular lymphocyte (LGL) leukemia using a novel cancer nanotechnology platform. We propose to administer systemically targeted C6-ceramide cationic nanoimmunoliposome formulations encapsulating methotrexate and siRNAs to an established animal model of LGL leukemia. These studies will provide the foundation for utilizing this therapeutic approach in human subjects with this incurable disease.