基于PSPC1/TGF-β1信号通路的黄芪甲苷抑制非小细胞肺癌EGFR-TKI耐药作用机制研究

Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) represents an important first-line treatment for patients with non-small cell lung cancer (NSCLC). However, acquired drug resistance seriously hampers the clinical usage of EGFR-TKI. In the present study, we found that the third-generation EGFR-TKI Osimeritinib (OSI) resistant cell exhibited epithelial-mesenchymal transition (EMT) phenomenon and activation of the TGF-β signaling pathway. Regulation of TGF-β1 secretion and EMT via PSPC1 might be a potential breakthrough for addressing the problem of drug resistance. Astragaloside IV (AS-IV), the main active component of Radix Astragali, could inhibit the expression of PSPC1 and secretion of TGF-β1, as well as TGF-β1-induced EMT. The effect and molecular mechanism of AS-IV on resistance of EGFR-TKI OSI remain to be further studied. In this project, the PSPC1/TGF-β1 signaling pathway will be taken as the entry point for further study. Based on the RNA-Seq and bioinformatic analysis, we will further investigate the role of PSPC1/TGF-β1 signaling pathway in acquired resistance of EGFR-TKI OSI, as well as the effect and mechanism of AS-IV on PSPC1/TGF-β1 mediated EMT and acquired resistance of EGFR-TKI OSI. Relative study would clarify the therapeutic potential of PSPC1/TGF-β1 pathway for acquired resistance of EGFR-TKI, and also lay a foundation for the usage of AS-IV and Radix Astragali in treatment of drug resistant lung cancer.

表皮生长因子受体-酪氨酸激酶抑制剂（EGFR-TKI）是非小细胞肺癌的重要一线治疗手段，但耐药问题严重限制其临床应用。前期研究发现第三代EGFR-TKI Osimeritinib（OSI）耐药细胞发生明显的上皮间质转化（EMT）现象及TGF-β通路激活。PSPC1调控TGF-β1分泌及EMT或是解决耐药问题的潜在突破口。中药黄芪有效成分黄芪甲苷可抑制PSPC1表达和TGF-β1分泌，抑制TGF-β1诱导的EMT，其对OSI耐药的抑制作用及分子机制有待进一步研究。本项目拟以PSPC1/TGF-β1通路为切入点，在转录组测序和生物信息学分析等基础上深入探究该通路在OSI耐药中的作用及黄芪甲苷对该通路介导EMT和耐药的抑制作用与分子机制。相关研究可阐明PSPC1/TGF-β1通路在EGFR-TKI耐药中的治疗价值，亦为黄芪甲苷及中药黄芪在肺癌耐药治疗中的应用奠定基础。

表皮生长因子受体-酪氨酸激酶抑制剂（EGFR-TKI）是非小细胞肺癌的重要一线治疗手段，但耐药问题严重限制其临床应用。上皮间质转化（EMT）与EGFR-TKI获得性耐药密切相关，最新研究表明核旁斑点结构蛋白1（PSPC1）高表达增强转化生长因子TGF-β1的自分泌，激活相关信号通路并促进肿瘤EMT。前期研究发现第三代EGFR-TKI Osimeritinib（OSI）耐药细胞发生明显的EMT现象及TGF-β通路激活，且中药黄芪有效成分黄芪甲苷可抑制PSPC1表达和TGF-β1分泌，但其对OSI耐药的抑制作用及分子机制仍不清楚。本项目以PSPC1/TGF-β1通路为切入点，通过RNA-seq转录组测序和KEGG、GSEA分析等生物信息学分析方法，证实EGFR-TKI OSI耐药细胞的EMT现象和TGF-β信号通路的激活密切相关。进一步通过基因敲除及过表达等手段证实PSPC1的高表达能够促进肺癌细胞TGF-β1的分泌以及TGF-β/Smad信号通路的激活并介导EMT现象，且促进了肺癌细胞对OSI的耐药性。黄芪甲苷处理能够抑制PSPC1蛋白表达和TGF-β1的分泌，抑制TGF-β/Smad信号通路介导的EMT，进一步的体外细胞水平药效学实验和体内小鼠移植瘤模型研究结果显示，黄芪甲苷和OSI联合用药能够抑制OSI所诱导的TGF-β信号通路激活引起的EMT现象，增强OSI的体内外抗肿瘤作用。相关研究结果在一定程度上阐明PSPC1/TGF-β1通路在EMT介导EGFR-TKI耐药中的作用，为EGFR-TKI耐药问题的解决及临床治疗策略开发提供了支撑，亦为中药黄芪及其有效成分黄芪甲苷在肺癌治疗中的应用奠定基础。