YAP通过调控上皮间质转化促进非小细胞肺癌EGFR-TKIs耐药的发生及机制研究

Despite the benefits shown with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs) treatment in non-small cell lung cancer (NSCLC) patients, their clinical efficacy is limited by the development of acquired resistance. Recent evidences suggest epithelial-mesenchymal transition (EMT) is one of the EGFR-TKIs acquired resistance etiologies. Our preliminary data have shown that Yes-associated protein (YAP) is overexpressed on the EGFR-TKIs resistant cell line and promotes EMT in NSCLC cells. Furthermore, it is reported that YAP has physically interaction with β-catenin，which promotes the expression of mesenchymal markers, such as vimentin and N-cadherin. We will explore the role of YAP in the development of EMT associated NSCLC EGFR-TKIs acquired drug resistance, and the molecular mechanisms underlying the crosstalk between YAP and β-catenin as well as the regulation of YAP-β-catenin in the EMT-associated protein expression from molecular, cellular, tissue and animal Levels using immunohistochemistry, Co-IP, ChIP. et al. Our study will provide the cellular and molecular basis for a novel therapeutic approach aimed at targeting YAP that delays or reverses resistance to EGFR-TKIs treatment in NSCLC.

表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKIs）已成为治疗NSCLC最有力武器之一，但其获得性耐药的发生制约了其临床应用。研究表明上皮细胞-间质转化（EMT）是EGFR-TKIs获得性耐药的重要机制之一。我们预实验结果显示YES激酶相关蛋白（YAP）在EGFR-TKIs耐药细胞株中呈高表达，可促进NSCLC细胞中EMT的转化，并可与β-catenin结合，促进间质特征分子Vimentin及N-cadherin表达。因此，本项目拟应用基因过表达及慢病毒干扰等技术探讨YAP在NSCLC EMT发生及EGFR-TKIs获得性耐药中的作用，采用Co-IP，ChIP及双荧光素酶报告基因方法对YAP与β-catenin相互作用进行深层次的分析，并阐明YAP调控EMT相关蛋白表达的作用机理。本研究从YAP这个新视点，进一步完善EGFR-TKIs获得性耐药的分子机制，并为临床逆转其耐药提供新的靶点。

Yes激酶相关蛋白(Yes-associated Protein,YAP)是Hippo信号通路下游的主要效应分子，具有促进细胞增殖，抑制细胞凋亡、维持干细胞表型等作用。YAP作为一个潜在的癌基因，其过表达或过度活化能够促进包括非小细胞肺癌(NSCLC)在内的多种肿瘤的发生和发展。我们研究发现YAP在NSCLC组织中的核表达显著高于癌旁组织。我们发现H1975细胞株上YAP呈高表达，而PC9 EGFR-TKI敏感细胞株上的YAP呈低表达。新生血管形成是NSCLC生长的关键步骤，也是EGFR-TKI耐药的重要机制。我们进一步研究发现YAP在肺腺癌血管生成中具有重要作用。研究发现，YAP的表达水平与内皮细胞标记分子CD31的表达呈正相关性。进一步研究表明YAP可通过外泌体(EVs)从肺腺癌细胞H1975中转移至人脐静脉内皮细胞(HUVECs)中，并能够影响HUVECs细胞的迁移及血管形成。本研究从YAP这个新视点，进一步完善EGFR-TKIs获得性耐药及血管生成的分子机制，为临床抗血管生成及逆转EGFR-TKIs耐药提供特异靶标。