Vitamin D Analogs as Adjuvants in Chemotherapy of Cancer

描述(由申请人提供)：这项提案的总体目标是开发基于维生素D的治疗方案，以补充人类急性髓系白血病(AML)的治疗，并设计预防策略。具体地说，我们将专注于鉴定维生素D的生理形式1，25-二羟基维生素D3的类似物(1，25D和类似物统称为“Deltanid”)，它们在与鼠尾草酸联合给药时对白血病细胞最有效。我们将研究基因表达的变化，以及可以作为这种治疗反应的生物标记物的其他细胞变化。新鲜从患者体内获得的AML细胞和已建立的培养中的细胞将用于研究细胞分化、分化抵抗、细胞周期停滞和在治疗性毒性药物存在的情况下的生存机制。大量先前的观察表明，Deltanid诱导调控单核细胞分化的基因表达，但也可以导致分化抵抗(特异性目标1)，分化相关的细胞周期停滞(特异性目标2)，以及依赖于microRNA32和连接支架蛋白hKSR2与NFkB复合体的信号通路(特异性目标3)的细胞存活变化。将特别注意已被批准用于人类给药的Deltan类化合物，其分化活性被鼠尾草酸高度增强。该项目将通过多种方法完成，包括向培养细胞中添加药物、反义寡核苷酸、siRNA、分子诱饵和转基因质粒构建物，以研究这些操作的分子后果，这些操作将通过免疫印迹、定量RT-PCR、免疫沉淀和其他分子技术来确定。将通过细胞表面和分子标志物的测定以及各种酶的活性和表达来监测细胞的分化。基础研究中获得的信息将被用来指导Deltanid的临床试验及其与分化促进剂鼠尾草酸的组合，而对白血病细胞的体外翻译研究将有助于确定对Deltanid的反应生物标志物，并识别最适合启动计划中的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，而不是依赖有毒药物来对抗癌症和血液恶性肿瘤，已经有效地治疗了其中一些疾病。我们建议将其开发用于治疗和预防被称为急性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，但从商业来源找到治疗方法不太可能受到关注。因此，急性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 vitamin D-based therapeutic regimens to supplement the treatment, and design strategies for the prevention, of human acute myeloid leukemia (AML). Specifically, we will focus on the identification of analogs of the physiological form of vitamin D, 1,25- dihydroxyvitamin D3 (1,25D and analogs are collectively dubbed "deltanoids") which are the most effective when administered to leukemia cells in combination with Carnosic acid . We will study the alterations in gene expression, and other cellular changes that can be used as biomarkers of response to this treatment. AML cells ex vivo, freshly obtained from patients, and cells in established cultur will be used for studies of cell differentiation, resistance to differentiation, cell cycle arrest,and survival mechanisms in the presence of therapeutic toxic agents. The rationale is provided by numerous previous observations that deltanoids induce expression of genes which regulate monocytic differentiation but also can cause resistance to differentiation (Specific Aim 1), the differentiation-associated cell cycle arrest (Specific Aim 2), and cell survival changes dependent on microRNA32 and on signaling pathways that link the scaffold protein hKSR2 with NFkB complex(Specific Aim 3). Special attention will be given to deltanoids already approved for human administration the differentiation activity of which is highly enhanced by Carnosic acid. This project will be accomplished by a variety of approaches, including addition to cultured cells of pharmacological agents, antisense oligonucleotides, siRNAs, molecular 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 molecular techniques. Differentiating cells will be monitored by determination of cell surface and molecular markers, as well as by the activity and the expression of various enzymes. The information obtained in basic studies will be utilized to guide development of Clinical Trials of deltanoids, and their combinations with the differentiation enhancer carnosic acid, while translational studies on leukemic cells ex vivo will serve to identify biomarkers of responsiveness to deltanoids and the recognition of subgroups of myeloid leukemias which will be the most suitable for the initiation of planned clinical trials. PUBLIC HEALTH RELEVANCE: Differentiation therapy, which depends on the activation of existing cellular programs rather than on toxic drugs to combat cancers and blood malignancies is already effective as the treatment of some of these diseases. We propose to develop it as treatment and prevention of blood malignancy known as acute myeloid leukemia which, although kills approximately 15,000 people in USA every year, is unlikely to receive attention for finding its cure from commercial sources. Therefore, acute myeloid leukemia can be considered an orphan disease and merits support from public sources for the development of novel therapy.