Preclinical Models and New Therapeutic Agents Unit, IRCCS-Regina Elena National Cancer Institute, Rome, Italy.
J Exp Clin Cancer Res. 2022 Apr 28;41(1):157. doi: 10.1186/s13046-022-02317-1.
Epithelial-to-mesenchymal transition (EMT) encompasses a highly dynamic and complex key process which leads to metastatic progression. In high-grade serous ovarian carcinoma (HG-SOC), endothelin-1 (ET-1)/endothelin A receptor (ETR) signaling promotes EMT driving tumor progression. However, the complex nature of intertwined regulatory circuits activated by ET-1 to trigger the metastatic process is not fully elucidated.
The capacity of ET-1 pathway to guide a critical transcriptional network that is instrumental for metastatic growth was identified in patient-derived HG-SOC cells and cell lines through immunoblotting, q-RT-PCR, co-immunoprecipitation, in situ proximity ligation, luciferase reporter, chromatin immunoprecipitation assays and publicly available databases. Functional assays in HG-SOC cells and HG-SOC xenografts served to test the inhibitory effects of ET-1 receptors (ET-1R) antagonist in vitro and in vivo.
We demonstrated that ET-1/ETR axis promoted the direct physical ZEB1/YAP interaction by inducing their nuclear accumulation in HG-SOC cells. Moreover, ET-1 directed their engagement in a functional transcriptional complex with the potent oncogenic AP-1 factor JUN. This led to the aberrant activation of common target genes, including EDN1 (ET-1) gene, thereby creating a feed-forward loop that sustained a persistent ET-1/ZEB1 signaling activity. Notably, ET-1-induced Integrin-linked kinase (ILK) signaling mediated the activation of YAP/ZEB1 circuit driving cellular plasticity, invasion and EMT. Of therapeutic interest, treatment of HG-SOC cells with the FDA approved ET-1R antagonist macitentan, targeting YAP and ZEB1-driven signaling, suppressed metastasis in vivo in mice. High gene expression of ETR/ILK/YAP/AP-1/ZEB1 was a strong predictor of poor clinical outcome in serous ovarian cancer patients, indicating the translational relevance of this signature expression.
This study provides novel mechanistic insights of the ET-1R-driven mediators that support the ability of HG-SOC to acquire metastatic traits which include the cooperation of YAP and ZEB1 regulatory circuit paving the way for innovative treatment of metastatic ovarian cancer.
上皮间质转化（EMT）涵盖了一个高度动态和复杂的关键过程，导致转移进展。在高级别浆液性卵巢癌（HG-SOC）中，内皮素-1（ET-1）/内皮素 A 受体（ETR）信号促进 EMT 驱动肿瘤进展。然而，ET-1 激活的复杂调节回路网络激活以触发转移过程的复杂性质尚未完全阐明。
通过免疫印迹、q-RT-PCR、共免疫沉淀、原位邻近连接、荧光素酶报告基因、染色质免疫沉淀测定和公开可用的数据库，在患者来源的 HG-SOC 细胞和细胞系中鉴定 ET-1 途径指导对转移生长至关重要的关键转录网络的能力。HG-SOC 细胞和 HG-SOC 异种移植中的功能测定用于测试 ET-1 受体（ET-1R）拮抗剂在体外和体内的抑制作用。
我们证明，ET-1/ETR 轴通过诱导 HG-SOC 细胞中的核积累，促进 ZEB1/YAP 的直接物理相互作用。此外，ET-1 指导它们与强效致癌 AP-1 因子 JUN 一起参与功能转录复合物。这导致常见靶基因的异常激活，包括 EDN1（ET-1）基因，从而创建一个正反馈回路，维持持续的 ET-1/ZEB1 信号活性。值得注意的是，ET-1 诱导的整合素连接激酶（ILK）信号介导 YAP/ZEB1 电路的激活，驱动细胞可塑性、侵袭和 EMT。值得治疗关注的是，用 FDA 批准的 ET-1R 拮抗剂马西替坦（macitentan）治疗 HG-SOC 细胞，靶向 YAP 和 ZEB1 驱动的信号，抑制了小鼠体内的转移。ETR/ILK/YAP/AP-1/ZEB1 的高基因表达是浆液性卵巢癌患者不良临床结局的强有力预测因子，表明该特征表达的转化相关性。
本研究提供了 ET-1R 驱动的介质的新的机制见解，这些介质支持 HG-SOC 获得转移特征的能力，包括 YAP 和 ZEB1 调节回路的合作，为转移性卵巢癌的创新治疗铺平了道路。
