Non-small cell lung cancer (NSCLC) is a malignancy that faces serious resistance challenges in treatment. In this study, we identified Piperlongumine as a promising therapeutic candidate to overcome Osimertinib resistance in NSCLC. We systematically investigated the inhibitory effect of Piperlongumine on NSCLC cells and confirmed that it could effectively inhibit the in vitro kinase activity of wild-type (WT), exon 19 deletion, and L858R/T790M-mutated EGFR. We also found that Piperlongumine-induced intrinsic apoptosis by interfering with the EGFR signaling pathway, which was characterized by the down-regulation of the anti-apoptotic protein Mcl-1. Further mechanistic studies revealed that Piperlongumine-induced degradation of Mcl-1 was dependent on the Akt-GSK3β signaling pathway. Additionally, Piperlongumine-promoted interaction between Mcl-1 and β-TRCP, thereby enhancing β-TRCP-mediated ubiquitination and the degradation of Mcl-1. Furthermore, Piperlongumine significantly inhibited tumor growth in both Osimertinib-sensitive and resistant NSCLC xenograft models. These findings highlight the potential of Piperlongumine as an effective agent in overcoming EGFR-targeted therapy resistance and suggest new avenues for its clinical application in NSCLC treatment.
