Epigenetic Synergy Between DNMT and EZH1/2 Inhibitors for Therapy in Solid Tumors

项目总结 DNA甲基转移酶抑制剂(DNMTi)，如FDA批准的核苷类似物5-氮杂-2‘-脱氧胞苷 (DAC)，是目前唯一可用的可以逆转癌细胞DNA异常甲基化的临床药物 并已成为提高癌症免疫治疗疗效的潜在手段。然而，DNA 这些药物的去甲基化效用，特别是在实体肿瘤中，没有达到预期的下游 在临床前模型中看到的转录后果。因此，调节DNMT的新治疗策略 这些活动是迫切需要的，并直接在这个孢子项目中得到解决。我们的初步数据显示， 几种临床应用的EZH1/2抑制剂阻断PRC2在特定肿瘤中的代偿抑制活性 DAC去除DNA甲基化导致的抑制基因和重复元件。阻止此操作 抑制性“表观遗传开关”，我们认为这是患者对DNMTi耐药的关键因素 用这些药物治疗，可能是DNMTi EZH1/2i降低癌症相关抑制的观察到的协同作用的基础 基因和基因间转录沉默。我们的总体目标是定义转录协同的机制 和DNMTi EZH1/2i导致的免疫串扰，并评估这种表观遗传学的临床潜力 治疗组合，单独使用，并作为免疫治疗的引子。为此，我们将(目标1)定义癌症 细胞内在染色质调节机制及参与分子和治疗的细胞通路 联合应用EZH1/2和DNMT抑制作用。同时，我们将(目标2)在小鼠模型中确定 检查点治疗抵抗病--EZH1/2联合DNMT对肿瘤的抑制作用 与免疫细胞和那些依赖于两者之间相互作用的细胞相比。此外，拟议的1期临床 试验，包括广泛相关的科学终点，将(目标3)验证组合EZH1/2的影响 和DNMT抑制剂治疗对免疫反应基因信号通路和肿瘤微环境的影响 多种实体瘤类型。我们的研究的影响包括：1)定义了分子的可开发机制 与DNMTi治疗相关的串扰；2)使DNMTi EZH1/2i治疗能够有效地临床应用； 3)揭示相关的生物标记物，以评估药物在患者肿瘤中的作用；以及4)扩大机会 检查站和靶向免疫治疗组合。

PROJECT SUMMARY DNA methyltransferase inhibitors (DNMTi), such as the FDA-approved nucleoside analog 5-aza-2'-deoxycytidine (DAC), are currently the only available clinical drugs that can reverse abnormal DNA methylation in cancer cells and have emerged as a potential means to increase the efficacy of immunotherapy in cancer. However, the DNA de-methylation utility of these agents, particularly in solid tumors, does not attain the desired downstream transcriptional consequences seen in preclinical models. As such, novel therapeutic strategies to regulate DNMT activity are urgently needed and are directly addressed in this SPORE project. Our preliminary data shows that several clinically applied EZH1/2 inhibitors block compensatory repressive activity of PRC2 at select tumor suppressor genes and repeat elements consequent to DNA methylation removal by DAC. Blocking this repressive “epigenetic switch,” which we propose is a key contributor to DNMTi resistance seen in patients treated with these drugs, may underlie an observed synergy of DNMTi+EZH1/2i to de-repress cancer-associated genic and intergenic transcriptional silencing. Our overall goal is to define mechanisms of transcriptional synergy and immune crosstalk consequent to DNMTi+EZH1/2i and evaluate the clinical potential of this epigenetic therapeutic combination, alone, and as a primer to immunotherapy. To this end, we will (Aim 1) define cancer cell-intrinsic chromatin regulatory mechanisms and cellular pathways involved in the molecular and therapeutic effects of combined EZH1/2 and DNMT inhibition. Concurrently, we will (Aim 2) determine in mouse models of checkpoint therapy resistant disease, the antitumor effects of combined EZH1/2 and DNMT inhibition on cancer vs. immune cells and those dependent on interactions between the two. In addition, a proposed Phase 1 clinical trial, inclusive of extensive correlative science endpoints, will (Aim 3) validate the impact of combination EZH1/2 and DNMT inhibitor therapy on immune-response gene signaling circuits and the tumor microenvironment across multiple solid tumor types. Impacts of our studies include: 1) defining exploitable mechanisms of molecular crosstalk associated with DNMTi therapy; 2) enabling effective clinical application of DNMTi+EZH1/2i therapy; 3) revealing correlative biomarkers to assess drug action in patient tumors; and 4) expanding opportunities for checkpoint and targeted immunotherapy combinations.