Replication stress response defects predict and enhance immune checkpoint therapy response in triple negative breast cancer

复制应激反应缺陷可预测并增强三阴性乳腺癌的免疫检查点治疗反应

• 批准号: 10330595
• 负责人: Shiaw-Yih Lin
• 金额: $ 36.2万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10330595
• 关键词: Achievement; Affect; Bioinformatics; Biological Markers; Breast Cancer Cell; Breast Cancer Model; Breast Cancer Patient; CRISPR screen; Cancer Burden; Cells; Combined Modality Therapy; Consensus; Cytometry; Cytotoxic Chemotherapy; DNA; DNA biosynthesis; Defect; Disease; Effectiveness; Enzymes; Exhibits; Genetic Transcription; Immunization; Immunotherapy; Literature; Mediating; Mus; Mutation; Normal Cell; Outcome; Patient-Focused Outcomes; Patients; Pharmaceutical Preparations; Population; Predisposition; Production; Proliferating; Replication-Associated Process; Research; Resistance; Single-Stranded DNA; System; Testing; Therapeutic Effect; Tumor Burden; Work; biological adaptation to stress; checkpoint therapy; cohort; cytokine; follow-up; genetic signature; genome integrity; immune checkpoint blockade; immunogenic; immunogenicity; improved; improved outcome; in vivo; knock-down; mouse model; multiplexed imaging; neoplastic cell; novel; overexpression; patient prognosis; patient subsets; potential biomarker; predicting response; predictive marker; replication stress; response; therapy outcome; treatment response; triple-negative invasive breast carcinoma; tumor; tumor microenvironment; tumor-immune system interactions

Project Summary The lack of specific targets for the treatment of triple-negative breast cancer (TNBC) is a major challenge, as many TNBCs do not respond to cytotoxic chemotherapies. Immune checkpoint blockade (ICB) has yielded promising results in both advanced and early-stage TNBC and is expected to substantially improve the overall prognosis of patients with this disease. However, since TNBC is not inherently immunogenic, it is important to identify patients who would benefit most from immunotherapy and to identify agents that can prime the tumor microenvironment to enhance the therapeutic effects. TNBC is known to exhibit high levels of replication stress, which occurs when the DNA replication machinery encounters obstacles that impede the replication process. In normal cells, replication stress activates the replication stress response (RSR) to maintain genome integrity. Defective RSR allows cells with high replication stress to survive and proliferate. Recently, we have identified a gene signature that represents defects in RSR (RSRD). We found this RSRD signature to be highly enriched in TNBC cells. Furthermore, RSRD-high TNBC cells accumulate cytoplasmic DNA and induce STING-dependent cytokine production, which is required for the effectiveness of ICB. Intriguingly, the RSRD signature score correlates perfectly with the response of TNBC to ICB in syngeneic mouse models, and it accurately predicts ICB response across 5 low–mutation-burden tumor lineages. All these intriguing findings support the hypotheses that RSRD may act as a key determinant of ICB outcomes in low–mutation-burden cancers, including TNBC, and that RSRD-enhancing drugs may sensitize ICB-resistant TNBC to immunotherapy. These hypotheses will be tested via 3 specific aims. (1) To determine how the immune microenvironment is modified in RSR-defective TNBC. We will use a highly multiplexed imaging mass cytometry panel to determine how RSRD remodels the immune microenvironment of TNBC and induces susceptibility to ICB. In addition, we will manipulate the RSR status in TNBC cells to assess the relationship between RSR defects and immunotherapy response. (2) To identify causative drivers of RSRD-high–mediated ICB responsiveness in TNBC. Our preliminary studies suggest that RSR defects may drive immunotherapy response through accumulation of immunostimulatory cytosolic single-stranded DNA (ssDNA). We will, therefore, seek to manipulate the cytosolic ssDNA level in TNBC models to determine whether cytosolic ssDNA is indeed a causative driver of ICB responsiveness in TNBC. In addition, to understand why our RSRD gene signature predicts response to ICB in TNBC, we will apply an in vivo CRISPR screen to determine what transcriptional changes contained within our RSRD gene signature cause this response. (3) To develop novel combination therapy to convert RSRD-low TNBC to RSRD-high to improve their response to ICB. Using cutting-edge systems and bioinformatics approaches, we have identified many potential RSRD-inducing agents. We will assess the 6 most promising candidates and identify the best candidate compound that can effectively sensitize RSRD-low TNBC to ICB.

项目摘要 缺乏治疗三阴性乳腺癌（TNBC）的特异性靶点是一个重大挑战， 许多TNBC对细胞毒性化疗没有反应。免疫检查点阻断（ICB）已经产生了 在晚期和早期TNBC中取得了令人鼓舞的结果，预计将大大改善整体 这种疾病患者的预后。然而，由于TNBC不是固有免疫原性的，因此重要的是 确定从免疫治疗中获益最多的患者，并确定可以引发肿瘤的药物 微环境以增强治疗效果。已知TNBC表现出高水平的复制应激， 当DNA复制机制遇到阻碍复制过程的障碍时，就会发生这种情况。在 在正常细胞中，复制应激激活复制应激反应（RSR）以维持基因组完整性。 有缺陷的RSR允许具有高复制应激的细胞存活和增殖。最近，我们发现了一个 代表RSR（RSRD）缺陷的基因签名。我们发现这个RSRD信号高度富集在 TNBC细胞。此外，RSRD-高TNBC细胞积累细胞质DNA并诱导STING依赖性细胞凋亡。 细胞因子的产生，这是ICB有效性所必需的。有趣的是，RSRD的签名得分 与同基因小鼠模型中TNBC对ICB的反应完全相关，并且它准确地预测了 5种低突变负荷肿瘤谱系的ICB缓解。所有这些有趣的发现都支持了 RSRD可能是低突变负荷癌症（包括TNBC）ICB结局的关键决定因素， 并且RSRD增强药物可以使ICB抗性TNBC对免疫疗法敏感。这些假设将 通过三个具体目标进行测试。(1)为了确定如何在RSR缺陷的免疫微环境被修改， TNBC。我们将使用一个高度多重成像质量细胞仪面板，以确定如何RSRD重塑 TNBC的免疫微环境，并诱导对ICB的易感性。此外，我们将操纵RSR 在TNBC细胞中的RSR状态，以评估RSR缺陷和免疫治疗应答之间的关系。(2)到 鉴定TNBC中RSRD高介导的ICB反应性的致病驱动因素。我们的初步研究表明 RSR缺陷可能通过免疫刺激性胞质内毒素的积累来驱动免疫治疗反应， 单链DNA（ssDNA）。因此，我们将寻求在TNBC模型中操纵胞质ssDNA水平。 以确定胞质ssDNA是否确实是TNBC中ICB反应性的致病驱动因素。此外，本发明还提供了一种方法， 为了理解为什么我们的RSRD基因特征预测TNBC对ICB的反应，我们将应用体内CRISPR技术， 筛选，以确定我们的RSRD基因签名中包含的转录变化导致这一点 反应(3)开发新的组合疗法以将RSRD低的TNBC转化为RSRD高的TNBC，以改善其治疗效果。 对ICB的回应使用尖端系统和生物信息学方法，我们已经确定了许多潜在的 RSRD诱导剂。我们将评估6个最有前途的候选人，并确定最佳候选人 本发明的化合物可以有效地使RSRD低的TNBC对ICB敏感。