Linking Epigenetic-Therapy Induction of Inflammasome Signaling to Generation of a BRCAness Phenotype

摘要 PARP抑制剂（PARPi）耐药性仍然是临床障碍，治疗仅限于乳腺癌和卵巢癌 (OC)BRCA突变的患者，以及BRCA完整的OC患者中观察到的一些活性。我们的临床前 研究表明，将低甲基化剂（DNMT抑制剂）和新型PARPi talazoparib组合， 通过诱导炎性小体抑制乳腺和OC中的肿瘤生长，而不管BRCA突变状态如何 产生BRCAness表型的信号传导，协同引起癌细胞死亡。这导致了剂量- 在辉瑞和Astex资助的TNBC中进行I期临床试验，我们提出了一项II期试验， BRCA完整的乳腺和OC患者中的DNMTi和PARPi，包括系列患者的相关分析 使用DNMTi-PARPi处理的免疫活性小鼠进行的体外和体内样本和机制研究 联合治疗该提案的总体目标是将PARPi治疗的益处扩大到更大程度。 更大的患者群体，并进一步剖析PARPi细胞毒性和耐药性的机制。我们的中央 一种假说是表观遗传治疗诱导的炎性体信号传导产生BRCAness， PARPi在BRCA-活性TNBC和OC中的疗效。我们提出三个目标。目的1：检验假设 结合DNMTi + PARPi产生STING依赖性IFN和炎性体信号传导， 一种BRCAness表型，可增加肿瘤微环境中的抗肿瘤免疫力。我们 假设DNMTi + PARPi激活STING和炎性体信号传导，导致BRCA中的BRCAness- 精通TNBC和OC。我们将对将免疫信号与BRCAness联系起来的因素进行机制研究 用PARPi-DNMTi处理的免疫活性小鼠中免疫亚群的表型、功能分析 组合.目的2：检验DNMTi与PARPi组合激活反应性细胞的假设。 氧物质（ROS）介导的DNA损伤导致BRCA-熟练的TNBC和OC中的细胞死亡。 我们将研究DNMTi-PARPi组合产生的ROS如何增强DNA损伤反应（DDR） 信号传导，诱导STING活化并增强针对TNBC和OC肿瘤的免疫应答， 免疫活性小鼠。目的3：评估DNMTi-PARPi组合在TNBC中的临床活性， I/II期临床试验中的OC患者。在完成正在进行的第一阶段研究后，我们提出了一项第二阶段研究， 两个患者队列（一个TNBC，一个OC），一系列肿瘤活检和循环相关物，以测试机制 假设来自我们对患者样本的临床前研究。我们将探测BRCAness的调制- HRD、DDR基因、ROS信号、免疫信号基因和免疫亚群的功能分析。影响： 组合DNMTi-PARPi以诱导STING介导的免疫信号传导和直接诱导之间的新联系 BRCAness-HRD表型代表了一种潜在的重要治疗进展和治疗选择， 被诊断为TNBC和OC的女性，缺乏BRCA突变，并且有紧急的临床需求。 通过将免疫检查点疗法纳入该治疗策略，可以进一步增强疗效。

Abstract PARP inhibitor (PARPi) resistance remains a clinical hurdle, with therapy limited to breast and ovarian cancer (OC) patients with BRCA mutations, and some activity seen in OC patients with intact BRCA. Our preclinical studies demonstrate that combining a hypomethylating agent (DNMT inhibitor) and the novel PARPi talazoparib inhibited tumor growth regardless of BRCA mutation status in both breast and OC by inducing inflammasome signaling that generates a BRCAness phenotype, synergistically causing cancer cell death. This led to a dose- finding phase I clinical trial in TNBC funded by Pfizer and Astex and we propose a phase II trial combining a DNMTi and PARPi in breast and OC patients with intact BRCA that includes correlative analyses in serial patient samples and mechanistic studies in vitro and in vivo using immunocompetent mice treated with DNMTi-PARPi combination therapy. The overall goal of this proposal is to expand the benefit of PARPi therapy to a much larger group of patients and further dissect mechanisms of PARPi cytotoxicity and resistance. Our central hypothesis is epigenetic therapy-inducing inflammasome signaling generates BRCAness that enhances the efficacy of PARPi in BRCA-proficient TNBC and OC. We propose three aims. Aim 1: To test the hypothesis that combining DNMTi + PARPi generates STING-dependent IFN and inflammasome signaling leading to a BRCAness phenotype that increases anti-tumor immunity in the tumor microenvironment. We hypothesize that DNMTi + PARPi activates STING and inflammasome signaling leading to BRCAness in BRCA- proficient TNBC and OC. We will conduct mechanistic studies of factors linking immune signaling to BRCAness phenotype, functional analysis of immune subsets in immune-competent mice treated with PARPi-DNMTi combination. Aim 2: To test the hypothesis that DNMTi in combination with PARPi activate reactive oxygen species (ROS)-mediated DNA damage leading to cell death in BRCA-proficient TNBC and OC. We will investigate how ROS generated by DNMTi-PARPi combination enhances DNA damage response (DDR) signaling, induces STING activation and enhances immune responses against TNBC and OC tumors using immune-competent mice. Aim 3: To assess the clinical activity of DNMTi-PARPi combination in TNBC and OC patients in phase I/II clinical trials. After completing the ongoing phase 1, we propose a phase II study in two patient cohorts (one TNBC, one OC), serial tumor biopsies and circulating correlatives to test mechanistic hypotheses derived from our preclinical studies in patient samples. We will probe modulation of BRCAness- HRD, DDR genes, ROS signaling, immune signaling genes and functional analysis of immune subsets. Impact: Combining DNMTi-PARPi to induce a novel link between STING-mediated immune signaling and direct induction of a BRCAness-HRD phenotype represents a potentially important treatment advance and therapeutic option for women diagnosed with TNBC and OC who lack BRCA mutations and for which there is an urgent clinical need. Efficacy may be further enhanced by including immune checkpoint therapy to this treatment strategy.