Bee venom prompts the inhibition of gefitinib on proliferation, migration, and invasion of non-small cell lung cancer cells via EGFR-mediated autophagy

It has been confirmed that bee venom (BV) can inhibit tumor metastasis of lung cancer cells induced by epidermal growth factor, suggesting the inhibitory role of BV on the regulation of epidermal growth factor receptor (EGFR), and may synergistically promote the anti-lung cancer effect of EGFR tyrosine kinase inhibitor gefitinib. This paper aims to ascertain the therapeutic potentials of BV combined with gefitinib against non-small cell lung cancer (NSCLC) in vitro. As results, the content of the main component melittin in air-dried BV was determined by HPLC. Subsequently, it was found that BV significantly inhibited the proliferation of NSCLC PC-9 and NCI-H1299 cells, but not generated apparent toxicity to human normal lung epithelial BEAS-2B cells. Meanwhile, the combination of BV and gefitinib also significantly inhibited the proliferation of these two cells, and suppressed the migration and invasion of PC-9 cells. By bioinformatics analysis and molecular docking, it was predicted that the main component melittin in BV could act on the cell membrane and transmembrane protein EGFR. Ultimately, Western blot assays showed BV alone or combined with gefitinib significantly decreased the protein expression of phosphorylated EGFR (p-EGFR) and the protein expression ratio of p-EGFR to EGFR, and increased the protein expression ratio of LC3-II to LC3-I in PC-9 cells or epidermal growth factor-activated PC-9 cells. The results demonstrated that BV could prompt the inhibition of gefitinib on proliferation, migration, and invasion of NSCLC cells via EGFR-mediated autophagy, showing the synergistic anti-NSCLC potential when combined with gefitinib.