WEE1抑制剂AZD1775增强卵巢癌组织免疫反应性的作用机制及其应用研究

The immunotherapy effect towards ovarian cancer is poor, mainly because of the facts of limited gene mutation, low tumor mutation burden (TMB), and weak antigenicity in ovarian cancer. Then, how to effectively strengthen the tumor immune reactivity is the key to improve ovarian cancer treatment effect. In previous study, we treated ovarian cancer cell-lines with AZD1775, a WEE1 inhibitor whose classic mechanism is to targeted DNA repair pathway. We found that the agent also leads to virus-like reaction and enhanced antigen-presenting abilities in ovarian cancer cells. Based on the mechanism of WEE1 inhibitor, we proposed that AZD1775 might play a more important role in tumor immune environment by increasing TMB and neoantigens in ovarian cancer cells, promoting the chemotaxis and infiltration of lymphocytes in tumor tissues. To address this theory, we will use the in vivo murine-derived ovarian cancer model, single-cell sequencing of the T lymphocyte, the analysis of T Cell Receptor (TCR), the analysis of neoantigen, patient-derived organotypic tumor spheroids (PDOTS) model, to systematically study the role and molecular mechanisms of AZD1775 on ovarian cancer immunomicroenvironment. Also, we will explore the possibility of combined implication of DNA repair pathway targeted therapy and immune checkpoint therapy, which might provide a novel direction in ovarian cancer treatment.

肿瘤免疫治疗在卵巢癌中效果不佳，主要原因在于卵巢癌基因突变有限、肿瘤突变负荷低、抗原性不强，如何有效增强肿瘤组织免疫反应性是改善卵巢癌治疗效果的关键。我们在应用WEE1抑制剂AZD1775处理卵巢癌细胞的研究中发现，除了影响肿瘤细胞DNA损伤修复的经典机制外，该抑制剂还能导致肿瘤细胞病毒样反应和抗原提呈性增强等免疫效应。针对WEE1抑制剂的作用原理，我们推测其可能通过造成肿瘤突变负荷增加、肿瘤新生抗原产生和促进淋巴细胞的趋化和浸润等新机制，在肿瘤免疫微环境中发挥更重要作用。本研究将利用鼠源性卵巢癌体内模型、T细胞单细胞测序和TCR分析、肿瘤新生抗原形成分析、以及患者来源的器官型肿瘤微球体（PDOTS）模型进行临床验证，系统研究AZD1775对卵巢癌免疫微环境的影响及分子机制，并探讨DNA损伤修复靶向治疗与免疫检查点靶向治疗联合应用的可能性，为卵巢癌的治疗提供一个新的方向。

肿瘤免疫治疗在卵巢癌中效果不佳，主要原因在于卵巢癌基因突变有限、肿瘤突变负荷低、抗原性不强，如何有效增强肿瘤组织免疫反应性是改善卵巢癌治疗效果的关键。我们在应用 WEE1抑制剂AZD1775处理卵巢癌细胞的研究中发现，除了影响肿瘤细胞DNA损伤修复的经典机制外，该抑制剂还能导致肿瘤细胞病毒样反应和抗原提呈性增强等免疫效应。针对WEE1抑制剂的作用原理，我们推测其可能通过造成肿瘤突变负荷增加、肿瘤新生抗原产生和促进淋巴细胞的趋化和浸润等新机制，在肿瘤免疫微环境中发挥更重要作用。在这项研究中，我们证明了靶向WEE1通过双链RNA (dsRNA)病毒防御途径上调免疫信号，即使在cGAS/ sting缺陷的肿瘤中也会对免疫检查点封锁产生反应，这是多种癌症类型的典型表型。WEE1抑制通过下调FOXM1缓解SETDB1/ H3K9me3的抑制，从而增加内源性逆转录病毒元件(ERVs)的表达。ERVs触发dsRNA应激和干扰素反应，在多种肿瘤模型中增加抗肿瘤T细胞的招募，同时PD-L1升高。此外，结合WEE1抑制和PD-L1阻断，以CD8+ T细胞依赖的方式诱导显著的肿瘤消退。WEE1抑制诱导的病毒防御特征为患者选择WEE1和ICB联合治疗提供了一个潜在的信息丰富的生物标志物。WEE1抑制刺激抗肿瘤免疫并增强对ICB的敏感性，为WEE1抑制剂与ICB联合应用于临床试验提供了依据。