Effect of Cerium on Expression and Activity of MMP-9 from Human Carcinoma of Bladder Cell Line

The effects of Ce4+ on cell survival, expression and activity of matrix metalloproteinase-9 （MMP-9） with MTT colorimetry and gelatin zymography assays in human bladder carcinoma cell line was studied. The results indicate that the lower concentration of Ce4+ (0.01 mmol·L-1) has no influence on cell growth, but inhibits extremely expression of MMP-9 and increases its activity, whereas the higher concentration of Ce4+ (1.0 mmol·L-1) can inhibit all of them. The results raise the possibility that Ce4+ may have beneficial effects in attenuating invasion and metastasis of malignant tumors.