Epigenetic Regulation of Immune Genes in Cancer Treatment and Vaccine Protocols

描述（由申请人提供）：在本提案中，我们将尝试进一步定义使用表观遗传因子增强肿瘤免疫的机制途径以及提高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。我们的具体目的是确定：1)在B16黑色素瘤疫苗模型中，组蛋白去乙酰化酶抑制剂（HDACi）增强抗原呈递的作用；2)表观遗传模型中NK细胞对免疫的贡献；3) hdac联合热疗、放疗的疗效观察；4)全身性HDACi治疗联合其他方式的效果。另一个主要目的是表征Dicer和microRNA在免疫基因调控中的作用。我们的研究已经确定了靶向几种miRNA机械成分的miRNA，包括Dicer。我们还定义了几种下调Dicer的应激（ROS、缺氧、dsRNA），并将确定Dicer表达被调控的途径。靶向Dicer的MiRNAs和sirna将用于去抑制沉默的基因，并确定这是否能增强免疫基因的表达，目前正在临床试验中与HDACi联合使用。拟议的研究是临床前研究，利用B16黑色素瘤、结肠癌和鳞状细胞癌头颈癌模型。我们的研究将采用体外免疫学分析、标准分子生物学技术和微阵列来表征基因和miRNA的表达。在手术中移除的新鲜H&N组织将为拟议的临床试验做准备。公共卫生相关性：本申请侧重于一种新型药物（组蛋白去乙酰化酶抑制剂）的临床前和机制研究，目前正在临床试验中进行评估。这些研究提出了一种新的机制，通过这种机制，这些药物可以以低毒性改善癌症治疗（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).