COX-2 inhibition and cancer: experimental findings and clinical correlates.

To test our hypothesis that Cyclooyxgenase-2 (COX-2) inhibitors would stop the growth of breast and prostate cancer cells in vitro, two breast (MCF-7, ZR75-1) and two prostate cancer cell lines (PC-3, DU145) were treated with rofecoxib (Vioxx) or NS398. Cell growth was measured by MTT at 24 and 72 hours. Statistical analysis was performed by ANOVA. Significant growth inhibition (p < 0.05) was observed in all cell lines in a dose-dependent manner after treatment with COX-2 inhibitors. Rofecoxib inhibited cellular proliferation by inducing (p < 0.001) apoptosis in breast cancer cells. Our study indicates that COX-2 inhibition reduces the growth of human breast and prostate cancer in vitro. Human studies are needed to evaluate the clinical utility of rofecoxib treatment in breast or prostate cancers.