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

摘要 PARP抑制剂(PARPI)耐药仍然是一个临床障碍，治疗仅限于乳腺癌和卵巢癌 (OC)BRCA突变的患者，在BRCA完整的OC患者中可见一些活动。我们的临床前研究 研究表明，将一种低甲基化试剂(DNMT抑制剂)与新型PARPI他唑巴联合使用 通过诱导炎症小体抑制肿瘤生长，而不考虑乳腺和OC中的BRCA突变状态 产生BRCAness表型的信号，协同导致癌细胞死亡。这导致了剂量- 在由辉瑞和ASTEX资助的TNBC中寻找I期临床试验，我们建议进行II期试验，将 BRCA完整的乳腺和OC患者的DNMTI和PARPI--附系列患者的相关分析 DNMTi-PARPI免疫活性小鼠的体内外标本及机制研究 联合疗法。这项建议的总体目标是将PARPI疗法的好处扩大到 并进一步剖析PARPI细胞毒性和耐药性的机制。我们的中央 假说是表观遗传疗法-诱导炎症体信号产生BRCACESS，从而增强 PARPI在精通BRCA的TNBC和OC中的疗效。我们提出了三个目标。目标1：检验假设 DNMTi+PARPI结合产生刺状依赖的干扰素和炎症体信号导致 一种在肿瘤微环境中增强抗肿瘤免疫的BRCAness表型。我们 假设DNMTi+PARPI激活了导致BRCA-BRCAness的刺痛和炎症小体信号 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 PARPI-DNMTi免疫活性小鼠免疫亚群的表型和功能分析 组合。目的2：验证DNMTi联合PARPI激活反应性的假说 氧物种(ROS)介导的DNA损伤导致BRCA熟练的TNBC和OC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) 信号转导，诱导STING激活，增强对TNBC和OC肿瘤的免疫应答 免疫能力强的小鼠。目的3：评价DNMTi-PARPI联合治疗TNBC和TBC的临床活性。 正在进行I/II期临床试验的OC患者。在完成正在进行的第一阶段后，我们建议在 两个患者队列(一个TNBC，一个OC)，连续的肿瘤活检和循环相关的测试机制 假说来源于我们在患者样本中的临床前研究。我们将探索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： 结合DNMTi-PARPI在刺激性免疫信号和直接诱导之间建立新的联系 BRCAness-HRD表型代表着一种潜在的重要的治疗进展和治疗选择 被诊断患有TNBC和OC的女性，缺乏BRCA突变，且临床上有迫切需求。 通过将免疫检查点疗法纳入这一治疗策略，可以进一步提高疗效。

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.