COX-2 is known to play an important role in cell metastasis and angiogenesis, and COX-2 is also over-expressed in colon cancer cells. In this study, we explored the anti-metastatic effects of genistein in HCT116 colon cancer cells, mediated effects on COX-2. Genistein treatments at different concentrations and for different durations inhibited proliferation and migration of HCT116 colon cancer cells. Genistein treatments decreased COX-2, MMP-9, Ang-1, VASP and VEGF. Treatment with celecoxib (an COX-2 inhibitor) decreased migration of HCT116 cells, while a combined treatment with celecoxib and genistein resulted in even futher decrease in cell migration. Inhibition of COX-2 by celecoxib treatment abolished these inhibitory effects on cell metastasis. COX-2 inhibition decreaesed MMP-9 expression in HCT116 cells, while a combined treatement with celecoxib and genistein resulted in even further decresed expression of MMP-9 in HCT116 cells. These results suggest that genistein induced both anti-proliferative and anti-metastatic effects by inhibiting COX-2 and MMP-9 activities. Genistein treatment also appeared to induce synergistic anti-metastatic effects by inhibition of COX-2 in HCT116 colon cancer cells. (Cancer Prev Res 17, 0-323, 2012)

Keywords: Genistein, Anti-metastatic effect, HCT116 colon cancer cells, COX-2, Celecoxib