Vitamin D Analogs as Adjuvants in Chemotherapy

描述(由申请人提供)： 这项建议的总体目标是开发分化疗法，以补充人类髓系白血病的治疗方案。我们将集中于鉴定最有效的生理形式维生素D的类似物，1，25-二羟基维生素D3(1，25D)在培养的白血病细胞中给予低浓度的维生素D，并研究基因表达的变化和其他细胞变化。Deltanid和1，25D诱导单核/巨噬细胞样分化，也将与目前用作食品防腐剂或添加剂的无毒物质或潜在的此类用途联合使用，以最大限度地提高Deltanid的分化活性。通过添加一种细胞内信号通路的抗炎抑制剂，将进一步增强这些分化剂的活性。已建立的白血病细胞系以及从患者新鲜获得的白血病细胞样本将用于细胞分化的研究。以前的观察表明，抗氧化剂提供了还原环境并诱导了基因的表达，这些基因补充了Deltanid反应基因的分化诱导作用。通过对信号通路的研究，尤其是对MAPK通路和转录因子的研究，将获得对分化控制的深入了解。这将通过添加药理学试剂、反义寡核苷酸、siRNA、转录因子诱骗和转基因质粒构建物来研究这些操作的分子后果，这将通过免疫印迹、定量RT-PCR、免疫沉淀和其他标准技术来确定。将通过测定表面标志物以及各种酶的活性和表达来监测分化细胞。基础研究中获得的信息将被用来指导新一代Deltanid和Deltanid与共诱导剂组合的开发，而对白血病细胞的体外翻译研究将有助于确定最适合启动临床试验的髓系白血病亚群。与公共卫生相关：分化疗法依赖于激活现有的细胞程序，而不是依靠有毒药物来对抗恶性肿瘤，已经作为治疗一些癌症的有效方法。我们建议将其开发用于治疗被称为髓系白血病的血液恶性肿瘤，尽管在美国每年约有15,000人死于这种疾病，但不太可能得到商业支持的关注，以寻找其治疗方法。因此，髓系白血病可以被认为是一种孤儿疾病，应该得到公共来源的支持，以开发新的治疗方法。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to develop differentiation therapy to supplement the treatment regimens for human myeloid leukemia. We will focus on the identification of the most effective analogs (deltanoids) of the physiological form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D) administered at low concentrations to leukemia cells in culture and study alterations in gene expression and other cellular changes. The deltanoids and 1,25D induce monocytic/macrophage-like differentiation and will also be administered in combination with nontoxic substances currently used as food preservatives or additives, or with potential for such use, to maximize the differentiation activity of of the deltanoids. Further enhancement of the activity of these differentiation agents will be explored by the addition of an anti-inflammatory inhibitor of an intracellular signaling pathway. Established lines of leukemia, as well as samples of leukemic cells freshly obtained from patients, will be used for studies of of cell differentiation. The rationale is provided by previous observation that antioxidants provide a reducing environment and induce expression of genes which complement the differentiation-inducing actions of deltanoid-responsive genes. Insight into differentiation control will be obtained by examination of signaling pathways with particular attention to MAPK pathways and to transcription factors. This will be accomplished by adding pharmacological agents, antisense oligonucleotides, siRNAs, transcription factor decoys, and transfected plasmid constructs to study the molecular consequences of these manipulations , which will be determined by immunoblotting, quantitative RT-PCR, immunoprecipitation, and other standard techniques. Differentiating cells will be monitored by determination of surface markers as well as the activity and the expression of various enzymes. The information obtained in basic studies will be utilized to guide development of a new generation of deltanoids and deltanoid combinations with co- inducers, while translational studies on leukemic cells ex vivo will serve to identify subgroups of myeloid leukemias most suitable for the initiation of clinical trials. PUBLIC HEALTH RELEVANCE: Differentiation therapy, which depends on the activation of existing cellular programs rather than on toxic drugs to combat malignant tumors, is already effective as the treatment of some cancers. We propose to develop it as therapy for blood malignancy known as myeloid leukemia, which although kills approximately 15,000 people in USA every year, is unlikely to receive attention from commercial support for finding its cure. Thus, myeloid leukemia can be considered an orphan disease, and merits support from public sources for the development of novel therapy.