Abstract
BACKGROUND: Melanoma is an aggressive skin cancer and a predominant cause of skin cancer-related deaths. A previous study has demonstrated the ability of butein to inhibit tumor proliferation and invasion. However, the anti-metastatic mechanisms and in vivo effects of butein have not been fully elucidated. METHODS: MTT cell viability assays were used to evaluate the antitumor effects of butein in vitro. Cytotoxic effects of butein were measured by lactate dehydrogenase assay. Anti-migratory effects of butein were evaluated by two-dimensional scratch and transwell migration assays. Signaling transduction and VEGF-releasing assays were measured by Western blotting and ELISA. We also conducted an experimental analysis of the metastatic potential of tumor cells injected into the tail vein of C57BL/6 mice. RESULTS: We first demonstrated the effect of butein on cell viability at non-cytotoxic concentrations (1, 3, and 10 μM). In vitro, butein was found to inhibit the migration of B16F10 cells in a concentration-dependent manner using transwell and scratch assays. Butein had a dose-dependent effect on focal adhesion kinase, Akt, and ERK phosphorylation in B16F10 cells. Butein efficiently inhibited the mTOR/p70S6K translational inhibition machinery and decreased the production of VEGF in B16F10 cells. Furthermore, the in vivo antitumor effects of butein were demonstrated using a pulmonary metastasis model. CONCLUSION: The results of the present study indicate the potential utility of butein in the treatment of melanoma.