Millettocalyxin B Inhibits Migratory Behavior of Lung Cancer Cells via Integrin α5 Suppression

Background/Aim: Integrin-targeting compounds have shown clinically significant benefits in many patients. Here, we examined the activity of millettocalyxin B, extracted from the stem bark of Millettia erythrocalyx, in lung cancer cells. Materials and Methods: The viability of human lung cancer cells was investigated by the 3-(4,5dimethylthiazol-2-yl)-2,5diphenyl tetrazoliumbromide (MTT) assay. Migration and invasion assays were performed. Phalloidin-rhodamine staining was used to determine the formation of filopodia. Western blot analysis and immunofluorescence staining were used to identify the signaling proteins involved in migration regulation. Results: Non-toxic concentrations (0-25 mu M) of millettocalyxin B reduced migration and invasion of lung cancer A549 cells. Filopodia were significantly reduced in millettocalyxin B treated cells. The migration regulatory proteins including integrin alpha 5, active FAK, active Akt, and Cdc42 were significantly decreased in Millettocalyxin B-treated cells. Conclusion: Our findings revealed a novel anti-migration and anti-invasion effects and the underlying mechanism of millettocalyxin B, which may be exploited for cancer treatment.