Abstract: AIM: To study the effect and mechanism of Delicaflavone on migration and invasion of gefitinib-resistant lung cancer cell line PC-9/GR.  METHODS: MTT assay was used to detect cell viability. Transwell and scratch assays were used to detect cell invasion and migration abilities. Western blotting was used to detect the expressions of MMP-9, MMP-2, E-cadherin, N-cadherin, Vimentin and PI3K/Akt/mTOR pathway-related proteins in PC-9/GR cells. RESULTS: Compared with control group, 20 mg/L Delicaflavone could significantly inhibit the viability of PC-9/GR cells for 24 h (P<0.05), while Delicaflavone below 10 mg/L had no significant effect on cell proliferation. The number of invasive cells and migrated cells were decreased significantly by Delicaflavone in a concentration-dependent way (P<0.05 and P<0.01). Delicaflavone could concentration-dependently reduce the expression of MMP-9, MMP-2, N-cadherin, vimentin (P<0.01), meanwhile up-regulate the expression of E-cadherin (P<0.01). In addition, Delicaflavone also decreased the expression of p-PI3K, p-Akt and p-mTOR in a concentration-dependent manner (P<0.01). CONCLUSION: Delicaflavone can inhibit the migration and invasion of PC-9/GR cells by regulating epithelial-mesenchymal transition via PI3K/Akt/mTOR pathway.

Key words: Delicaflavone, PC-9/GR cells, invasion, migration, PI3K/Akt/mTOR pathway