Targeting ceramide metabolism to overcome osimertinib resistance in egfr-mutant non-small cell lung cancer: an in vitro, network pharmacology, and in silico study

Abstract

Introduction: Osimertinib, an irreversible epidermal growth factor receptor inhibitor, is recognized for use in non-small cell lung cancer patients with the T790M resistance mutation. Though osimertinib offers a valuable advantage in survival of the patients, the occurrence of acquired resistance mechanisms confines the long-term efficacy of the therapy. Subsequently, evaluating the resistance mechanisms and generating alternative cure approaches are vital for improving therapeutic efficacy in advanced NSCLC. Herein, the aim was to research the effectiveness of inhibitors of acid ceramidases as promising alternative agents on targeting resistance-related cellular susceptibilities in osimertinib-sensitive (H1975/OS) and osimertinib-resistant (H1975/OR) NSCLC cells maintained under long-term exposure to osimertinib. Materials and Methods: The cells were exposed to carmofur and B13 for 24, 48, and 72 hours. Antiproliferative and cytotoxic effects were investigated using the sulforhodamine B assay, and half-maximal growth inhibition (GI50), Total Growth Inhibition (TGI), and half-maximal Lethal Concentration (LC50) concentrations were detected. Proapoptotic activity was investigated using annexin V and caspase 3/7 techniques on a cell analyzer. The morphological alterations were investigated using confocal microscopy. Results: The analysis results indicated a proapoptotic effect in both cell lines for carmofur and B13. Carmofur exerted moderate cytotoxicity at all concentrations, while B13 showed weak efficacy at the tested high agent concentrations. Remarkably, the resistant cells remained sensitive to carmofur and B13, indicating that ceramide metabolism may be effective in a therapeutic setting in resistant NSCLC. Discussion: The results offer strong support for further mechanistic and translational investigation. Conclusion: The results suggest that carmofur and B13 are promising alternatives for therapeutic targets in drug-resistant lung cancer cells.