Objectives: This research aims to investigate the mechanisms of resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in non-small-cell lung cancer (NSCLC), particularly focusing on the role of the epithelial-mesenchymal transition (EMT) within the tumor microenvironment (TME). Materials and Methods: We employed an in vitro three-dimensional organoid model that mirrors the physiology of human lung cancer. These organoids consist of lung cancer cells harboring specific EGFR mutations, human mesenchymal stem cells, and human umbilical vein endothelial cells. We analyzed EMT and drug resistance markers, and evaluated the effects of the anti-angiogenic agent Bevacizumab and micro-RNA miR200c. Results: The study identified a significant link between EMT and EGFR-TKI resistance. Notable findings included a decrease in E-cadherin and an increase in Zinc Finger E-Box Binding Homeobox 1 (ZEB1), both of which influenced EMT and resistance to treatment. Bevacizumab showed promise in improving drug resistance and mitigating EMT, suggesting an involvement of the Vascular Endothelial Growth Factor (VEGF) cascade. Transfection with miR200c was associated with improved EMT and drug resistance, further highlighting the role of EMT in TKI resistance. Conclusions: Our research provides significant insights into the EMT-driven EGFR-TKI resistance in NSCLC and offers potential strategies to overcome resistance, including the use of Bevacizumab and miR200c. However, due to the limitations in organoid models in replicating precise human cancer TME and the potential influence of specific EGFR mutations, further in vivo studies and clinical trials are necessary for validation.
Keywords: Epidermal Growth Factor Receptor (EGFR) mutations; drug resistance; epithelial–mesenchymal transition (EMT); non-small-cell lung cancer (NSCLC); organoid models.