Targeted Therapeutics of LGL Leukemia utilizing Ceramide Nanoliposomes

描述（由申请人提供）：本申请的广泛长期目标是设计、开发和优化用于治疗大颗粒淋巴细胞（LGL）白血病的下一代聚乙二醇化C6-神经酰胺阳离子脂质体制剂。LGL白血病由T细胞或自然杀伤（NK）细胞的克隆增殖引起。对于LGL白血病患者没有已知的治愈性疗法。白血病LGL对Fas诱导的细胞凋亡具有抗性，并显示高水平的活化的STAT 3，这是致癌信号传导的关键介质。在白血病LGL中抑制STAT 3导致存活蛋白Mcl-1的减少和对Fas介导的细胞凋亡的敏感性增加。该应用的基础是第一代C6-神经酰胺纳米脂质体，其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，即纳米级非聚集C6-神经酰胺脂质体提供了用于将疏水性化疗药物和/或siRNA全身靶向LGL白血病细胞的极其敏感、选择性、无毒、隐蔽、可生物降解和响应性平台。将在LGL白血病的Fischer F344大鼠模型中测试设计用于递送神经酰胺（C6神经酰胺）的细胞可渗透类似物以及靶向特异性siRNA和/或甲氨蝶呤的多功能纳米脂质体的潜在临床有用性。假设在神经酰胺掺入的脂质体中同时递送甲氨蝶呤和/或siRNA将在LGL白血病中具有协同功效。第一个特定目的将在已建立的动物模型中检验脂质体短链神经酰胺的全身递送抑制LGL白血病的假设。具体目标2将测试以下假设：聚乙二醇化阳离子脂质体允许在体外和体内将抑制性siRNA和化疗药物递送到LGL白血病细胞中，从而增强其抗白血病活性。具体目标3将检验以下假设：单克隆抗体与CD 8（LGL白血病的特异性标志物）的偶联将使治疗性脂质体在体外和体内靶向LGL白血病细胞。具体目标3中的实验是通过靶向癌细胞上表达的表面抗原来递送免疫脂质体的重要原理验证研究。本申请中概述的第二代癌症纳米技术平台的开发具有改善癌症治疗的潜力。 公共卫生相关性本申请的目标是使用新型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。我们建议给予全身靶向C6-神经酰胺阳离子纳米免疫脂质体制剂封装甲氨蝶呤和siRNA的LGL白血病的动物模型。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.