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

项目概要 DNA 甲基转移酶抑制剂 (DNMTi)，例如 FDA 批准的核苷类似物 5-aza-2'-脱氧胞苷 （DAC），是目前临床上唯一可以逆转癌细胞异常DNA甲基化的药物 并已成为提高癌症免疫疗法疗效的潜在手段。然而，DNA 这些药物的去甲基化效用，特别是在实体瘤中，没有达到所需的下游效果 临床前模型中观察到的转录后果。因此，调节 DNMT 的新治疗策略 这些活动是迫切需要的，并在该 SPORE 项目中直接得到解决。我们的初步数据表明 几种临床应用的 EZH1/2 抑制剂可阻断 PRC2 对选定肿瘤的代偿性抑制活性 DAC 去除 DNA 甲基化后产生的抑制基因和重复元件。阻止这个 抑制性“表观遗传开关”，我们认为这是患者中出现的 DNMTi 耐药性的关键因素 用这些药物治疗，可能是观察到的 DNMTi EZH1/2i 协同作用的基础，以去抑制癌症相关的 基因和基因间转录沉默。我们的总体目标是定义转录协同作用的机制 和 DNMTi EZH1/2i 引起的免疫串扰，并评估这种表观遗传的临床潜力 治疗组合，单独使用，以及作为免疫治疗的引物。为此，我们将（目标 1）定义癌症 参与分子和治疗的细胞固有染色质调节机制和细胞途径 EZH1/2 和 DNMT 联合抑制的效果。同时，我们将（目标 2）在小鼠模型中确定 检查点治疗耐药性疾病，联合EZH1/2和DNMT抑制对癌症的抗肿瘤作用 与免疫细胞以及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，包括广泛的相关科学终点，将（目标 3）验证 EZH1/2 组合的影响 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。我们研究的影响包括：1）定义分子的可利用机制 与 DNMTi 治疗相关的串扰； 2) 实现 DNMTi EZH1/2i 疗法的有效临床应用； 3）揭示相关生物标志物以评估药物对患者肿瘤的作用； 4) 扩大机会 检查点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.