Somayaji Ashwini, Shastry Chakrakodi Shashidhara
Department of Pharmacology, Faculty of Pharmacy, M.S. Ramaiah University of Applied Sciences, New BEL Rd, M S R Nagar, Karnataka- 560054, India.
Nitte Gulabi Shetty Memorial Institute of Pharmaceutical Sciences, Paneer, Karnataka, India.
Adv Pharm Bull. 2025 Mar 23;15(2):428-439. doi: 10.34172/apb.43809. eCollection 2025 Jul.
Combinatorial therapies are essential for treating advanced non-small cell lung cancer (NSCLC), particularly overcoming resistance to third-generation epidermal growth factor receptor (EGFR) like osimertinib (OSI). The Hippo signaling pathway, a critical regulator of cell proliferation, apoptosis, and tumor progression, is often dysregulated in NSCLC and contributes to chemo-resistance. This study investigated the potential of epigallocatechin-3-gallate (EGCG), a green tea polyphenol, to overcome OSI resistance by modulating the Hippo signaling pathway, specifically through inhibition of the YAP-1 (Yes-associated protein)-TEAD (TEA domain transcription factor)-CTGF (connective tissue growth factor) axis.
Using stepwise dose escalation, OSI-resistant (OR) clones were developed from EGFR T790M-mutated H460 cells. The anti-proliferative effects of EGCG were assessed, and synergistic interactions between OSI and EGCG were analysed using combination index (CI) values and the median effect concept. Mechanistic studies evaluated the co-treatment's impact on the Hippo signaling pathway, focusing on the inhibition of the YAP/TEAD/CTGF signaling axis.
The OR clones exhibited significantly higher IC values for OSI (25.12-28.48 µM) compared to parental H460 cells (2.74±0.2µM). EGCG treatment reduced cell viability in a concentration-dependent manner, with IC values of 102.54±0.23μM for H460 cells and 225.79-237.36 µM for OR clones. Combination treatment of OSI and EGCG showed strong synergy at a 1:2 molar ratio, with CI values indicating synergism across a range from IC to IC. Mechanistically, co-treatment suppressed the overexpression of the YAP/TEAD/CTGF axis, restoring Hippo pathway activity and reversing OSI resistance.
This study provides evidence that EGCG effectively targets the Hippo signaling pathway to overcome OSI resistance in NSCLC. The inclusion of EGCG in combinatorial therapies holds promise as a novel approach to combat therapeutic resistance and improve outcomes for patients with EGFR-mutated NSCLC.
联合疗法对于治疗晚期非小细胞肺癌（NSCLC）至关重要，尤其是克服对第三代表皮生长因子受体（EGFR）抑制剂如奥希替尼（OSI）的耐药性。Hippo信号通路是细胞增殖、凋亡和肿瘤进展的关键调节因子，在NSCLC中常发生失调，并导致化疗耐药。本研究调查了绿茶多酚表没食子儿没食子酸酯（EGCG）通过调节Hippo信号通路，特别是通过抑制YAP-1（Yes相关蛋白）-TEAD（TEA结构域转录因子）-CTGF（结缔组织生长因子）轴来克服OSI耐药性的潜力。
采用逐步剂量递增法，从EGFR T790M突变的H460细胞中培养出OSI耐药（OR）克隆。评估了EGCG的抗增殖作用，并使用联合指数（CI）值和中位效应概念分析了OSI与EGCG之间的协同相互作用。机制研究评估了联合治疗对Hippo信号通路的影响，重点是对YAP/TEAD/CTGF信号轴的抑制。
与亲本H460细胞（2.74±0.2μM）相比，OR克隆对OSI的IC值显著更高（25.12 - 28.48μM）。EGCG处理以浓度依赖的方式降低细胞活力，H460细胞的IC值为102.54±0.23μM，OR克隆的IC值为225.79 - 237.36μM。OSI与EGCG以1:2摩尔比联合治疗显示出强烈的协同作用，CI值表明在从IC到IC的范围内均存在协同作用。从机制上讲，联合治疗抑制了YAP/TEAD/CTGF轴的过表达，恢复了Hippo通路活性并逆转了OSI耐药性。
本研究提供了证据表明EGCG有效靶向Hippo信号通路以克服NSCLC中的OSI耐药性。在联合疗法中加入EGCG有望成为一种对抗治疗耐药性并改善EGFR突变NSCLC患者预后的新方法。
