Epigenetic Regulation of Immune Genes in Cancer Treatment and Vaccine Protocols

描述(由申请人提供)：在这项提案中，我们将尝试进一步定义使用表观遗传剂增强肿瘤免疫所涉及的机制途径，以及增强其有效性的改进策略。长期目标是将这项技术转化为临床应用。我们的具体目标是确定：1)组蛋白脱乙酰酶抑制剂(HDACi)处理的肿瘤细胞在B16黑色素瘤疫苗模型中增强抗原提呈的作用；2)NK细胞在表观遗传模型中对免疫的贡献；3)这些模型在HDACi与热疗和放射相结合时的有效性；4)HDACi系统治疗与其他方式相结合的效果。另一个主要目的是研究DICER和microRNA在免疫基因调控中的作用。我们的研究已经确定了针对几个miRNA机械组件的miRNAs，其中包括DICER。我们还定义了几种下调DICER的应激反应(ROS、缺氧、dsRNA)，并将确定调节DICER表达的途径。针对DICER的miRNAs和siRNAs将被用来抑制沉默的基因，并确定这是否与目前处于临床试验中的HDACi一起增强免疫基因的表达。拟议的研究是临床前研究，利用了B16黑色素瘤、结肠癌26以及鳞状细胞癌头颈癌模型。我们的研究将使用体外免疫学分析、标准分子生物学技术和微阵列来表征基因和miRNA的表达。手术中取出的新鲜H&N组织将被研究，为拟议的临床试验做准备。与公共卫生相关：这项应用侧重于一类新的药物(组蛋白脱乙酰酶抑制剂)的临床前和机制研究，目前正在进行临床试验。这些研究解决了一种新的机制，通过这种机制，这些药物可以改善低毒的癌症治疗(与标准化疗药物相比)。

DESCRIPTION (provided by applicant): In this proposal we will attempt to further define the mechanistic pathways involved in enhancing tumor immunity using epigenetic agents and improved strategies for enhancing their effectiveness. The long-term goal is to transfer this technology to clinical application. Our specific aims are to determine: 1) the role of enhanced antigen presentation by histone deacetylase inhibitor (HDACi) treated tumor cells in a B16 melanoma vaccine model; 2) the contribution of NK cells to immunity in the epigenetic model; 3) the efficacy of these models in combinations of HDACi with hyperthermia and radiation; 4) the effects of systemic HDACi therapy in combination with other modalities. An additional major aim is to characterize the role of Dicer and microRNA in immune gene regulation. Our studies have identified miRNAs which target several miRNA machinery components including Dicer. We also defined several stresses that downregulate Dicer (ROS, anoxia, dsRNA) and will determine the pathways by which expression of Dicer is regulated. MiRNAs and siRNAs targeting Dicer will be employed to de-repress silenced genes and to determine whether this enhances immune gene expression in combination with HDACi which are currently in clinical trials. The proposed studies are pre-clinical and exploit the B16 melanoma, colon26, as well as the SCC head and neck cancer models. Our studies will employ in vitro immunological assays, standard molecular biology techniques and microarrays for characterization of gene and miRNA expression. Fresh H&N tissue, removed at surgery, will be studied in preparation for a proposed clinical trial. PUBLIC HEALTH RELEVANCE: This application focuses on pre-clinical and mechanistic studies of a new class of agents (histone deacetylase inhibitors) now currently being evaluated in clinical trials. These studies address a novel mechanism by which these agents may improve cancer therapy with low toxicity (compared to standard chemotherapeutics).