Targeted Therapeutics of LGL Leukemia utilizing Ceramide Nanoliposomes

描述（由申请人提供）：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制剂，用于治疗大颗粒淋巴细胞（LGL）白血病。LGL白血病起源于T细胞或自然杀伤细胞（NK）的克隆性增殖。对于LGL白血病患者尚无已知的治愈疗法。白血病LGL对fas诱导的细胞凋亡具有抗性，并表现出高水平的活化STAT3， STAT3是致癌信号的关键介质。抑制STAT3在白血病LGL中导致存活蛋白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，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。具体目标集中在纳米级，非聚集的c6 -神经酰胺脂体为系统靶向疏水化疗药物和/或siRNA到LGL白血病细胞提供了高度敏感，选择性，无毒，隐身，可生物降解和响应的平台。多功能纳米脂质体的潜在临床用途将在Fischer F344大鼠LGL白血病模型中进行测试，该纳米脂质体被设计用于传递神经酰胺（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。假设在神经酰胺脂质体中同时递送甲氨蝶呤和/或siRNA将对LGL白血病具有协同作用。第一个特定的Aim将在一个已建立的动物模型中测试脂质体短链神经酰胺的全身递送抑制LGL白血病的假设。特异性目的2将验证聚乙二醇化的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。特异性目的3将验证一种假设，即结合一种单克隆抗体CD8 （LGL白血病的特异性标记物），在体内和体外将治疗性脂质体靶向LGL白血病细胞。特异性靶3的实验是通过靶向癌细胞表面抗原递送免疫脂质体的重要原理证明研究。本应用概述的第二代癌症纳米技术平台的发展具有改善癌症治疗的潜力。

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.