New activities of homoyessotoxin against lung cancer through the regulation of EGFR/PI3K/AKT pathway

Non-small cell lung cancer (NSCLC) remains a major cause of cancer-related mortality worldwide, emphasizing the need for novel therapeutic strategies. In this study, we demonstrate that homoyessotoxin (hYTXs), a marine-derived natural compound, exerts potent anti-NSCLC progression. Network pharmacology, molecular docking, molecular dynamics simulations, and SPR analysis confirmed a strong binding affinity between hYTXs and EGFR. Mechanistically, hYTXs disrupted EGFR trafficking by accelerating its endocytosis and enhancing its accumulation within lysosomes, thereby accelerating receptor degradation without altering EGFR mRNA levels. CHX chase and lysosomal inhibition assays further verified that hYTXs downregulated EGFR through post-translational regulation. This degradation led to suppression of downstream PI3K/AKT/ERK signaling, reduced phosphorylation of FOXO3a and p70S6K, and enhanced PTEN nuclear translocation. Functionally, hYTXs induced apoptosis, oxidative stress, S-phase arrest, mitochondrial dysfunction, and DNA damage in A549 cells, with comparable inhibitory potency in EGFR-mutant lines (PC9, H1975) but minimal cytotoxicity toward normal lung epithelial cells. In vivo, hYTXs significantly inhibited tumor growth and exhibited excellent safety based on serum biochemistry and lung histology. Collectively, hYTXs represents a promising next-generation EGFR-targeting compound that overcomes kinase-mutation-driven resistance by promoting receptor degradation rather than kinase inhibition.