Therapeutic Targeting of RNA Splicing in Triple-Negative Breast Cancer

三阴性乳腺癌（TNBC）是一种侵袭性乳腺癌亚型， 分子靶向疗法，并且占全世界每年约200，000例新诊断。 免疫调节剂，利用免疫系统对抗癌症的疗法，已经彻底改变了免疫系统。 治疗某些癌症，并且最近已被批准用于治疗TNBC。令人不安的是，TNBC 患者对这些疗法的反应是不均匀的，并且显著低于其他类型的癌症。 众所周知，TNBC在免疫学上是冷的，具有相对低水平的基线免疫浸润 限制了放大产生性抗肿瘤免疫应答的免疫调节剂的功效。一个伟大的 大量的努力集中在促进这些肿瘤中的免疫参与上。我们先前已经表明 TNBC中常见的致癌畸变会导致对RNA剪接干扰的超敏反应 机械.重要的是，多项研究，包括我们自己的研究（Bowling，Wang等，2021），已经揭示， 剪接体靶向治疗（STT）的治疗效果部分是由于参与宿主免疫 系统虽然这些发现为STT的临床部署带来了巨大希望，特别是联合应用 对于免疫调节剂，它们在激活抗肿瘤免疫中的作用的几个方面需要进一步研究。 认识在这里，我们建议询问触发病毒模仿的错误剪接RNA的种类， 引发肿瘤炎症和抗肿瘤免疫。 目标1。研究基于STT诱导的抗肿瘤免疫的组合治疗方法 反应我们的初步数据表明，STT治疗激活肿瘤内在的抗病毒信号传导， 改变与肿瘤微环境的相互作用。通过利用一个多样化的免疫能力强的群体， TNBC的同基因模型，我们将阐明STT诱导的免疫浸润变化，并评估 与免疫调节剂组合治疗以增强STT的功效。 目的2：确定内源性dsRNA介导的抗病毒信号传导的细胞调节剂。突出 致癌性畸变已被证明可调节基线和激动剂诱导的炎症信号传导， 肿瘤细胞事实上，我们已经在一组TNBC中观察到抗病毒转录反应的异质性， 具有STT诱导的dsRNA积累的细胞系。因此，我们将利用一种基于干扰素的基因， 筛选以鉴定对内源性dsRNA积累的细胞内在免疫应答的新调节剂。 目的3：评估STT诱导的刺激抗病毒信号的错误剪接RNA的特征。初步 研究表明，在临床环境中研究的STT的不同化学型导致不同的 抗病毒免疫信号。利用化学遗传微扰和新的RNA标记和测序 方法，我们将分析由不同剪接体扰动产生的免疫原性错误加工RNA RNA剪接是RNA剪接的一个组成部分，涵盖了整个RNA剪接循环。

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that is recalcitrant to molecular targeted therapies and accounts for about 200,000 new diagnoses per year worldwide. Immunomodulators, therapies that harness the immune system against cancer, have revolutionized the treatment of some cancers and have recently been approved for treatment of TNBC. Disappointingly, TNBC patient response to these therapies has been heterogeneous and significantly lower than other types of cancers. TNBCs are notoriously immunologically cold, with relatively low levels of baseline immune infiltration limiting the efficacy of immunomodulators that amplify productive antitumor immune response. Therefore, a great deal of effort has been focused on promoting immune engagement in these tumors. We have previously shown that oncogenic aberrations common in TNBC result in hypersensitivity to perturbation of the RNA splicing machinery. Importantly, multiple studies, including our own (Bowling, Wang, et al. 2021), have revealed that therapeutic efficacy of spliceosome-targeted therapies (STTs) is in part due to engaging the host immune system. While these discoveries hold great promise for clinical deployment of STTs, especially in combination with immunomodulators, several aspects of their role in activation of antitumor immunity require further understanding. Herein, we propose to interrogate the species of mis-spliced RNA that trigger viral mimicry and trigger tumor inflammation and antitumor immunity. Aim 1. Investigate combinatorial therapy approaches based on STT-induced antitumor immune response. Our preliminary data indicate that activation of tumor-intrinsic antiviral signaling by STT treatment modifies interaction with the tumor microenvironment. By leveraging a diverse cohort of immune-competent syngeneic models of TNBC, we will elucidate the STT-induced change in immune infiltrate and evaluate treatment in combination with immunomodulators to enhance the efficacy of STTs. Aim 2: Define cellular modulators of endogenous dsRNA-mediated antiviral signaling. Prominent oncogenic aberrations have been shown to modulate baseline and agonist-induced inflammatory signaling in tumor cells. Indeed, we have observed heterogeneity in antiviral transcriptional response across a panel of TNBC cell lines with STT-induced dsRNA accumulation. Thus, we will leverage an interferon reporter-based genetic screen to identify novel regulators of cell-intrinsic immune response to endogenous dsRNA accumulation. Aim 3: Evaluate features of STT-induced mis-spliced RNA that stimulate antiviral signaling. Preliminary studies indicate that distinct chemotypes of STTs being investigated in the clinical setting result in differential antiviral immune signaling. Using chemical genetic perturbation and novel RNA labeling and sequencing methods, we will profile immunogenic misprocessed RNA generated by perturbation of distinct spliceosome components encompassing the entirety of the RNA splicing cycle.