Icaritin suppresses the proliferation of human osteosarcoma cells in vitro by increasing apoptosis and decreasing MMP expression

Aim: To explore whether icaritin, a prenylflavonoid derivative of the Chinese tonic herb Epimedium, could suppress the proliferation of human osteosarcoma cells in vitro, and to elucidate the mechanisms of the action. Methods: Human osteosarcoma SaOS(2) cell line was used in the present study. The proliferation of the cells was examined using MTT assay and immunofluorescence DAPI staining. Cell motility was studied with the scratch assay. Cell apoptosis was determined by Annexin V-FITC and PI double staining using flow cytometry. Western blotting and RT-PCR were used to measure the expression of mRNAs and proteins in the cells. Results: Icaritin (5-15 mu mol/L) suppressed the proliferation of SaOS(2) cells in vitro in a dose-dependent manner. Furthermore, the cell motility was significantly decreased after exposure to icaritin. Moreover, icaritin (5 mu mol/L) time-dependently induced the apoptosis of SaOS(2) cells, markedly suppressed MMP-2 and MMP-9 expression, upregulated caspase-3 and caspase-9 expression, and increased the level of cleaved caspase-3 in the cells. Co-exposure to the caspase-3 inhibitor zVAD-fmk (10 mu mol/L) compromised the icaritininduced caspase-3 expression and apoptosis in SaOS(2) cells. Conclusion: Icaritin suppresses the proliferation of SaOS(2) human osteosarcoma cells by increasing apoptosis and downregulating MMP expression.