Atorvastatin and Celecoxib Inhibit Prostate PC-3 Tumors in Immunodeficient Mice

Purpose: To investigate the effects and mechanisms of atorvastatin and celecoxib administered individually or in combination on human prostate cancer PC-3 cells cultured in vitro or grown as xenograft tumors in immunodeficient mice. Experimental Design: Human prostate cancer PC-3 cells in culture were treated with atorvastatin and celecoxib alone or in combination. Severe combined immunodeficient (SCID) mice were injected s.c. with PC-3 cells. The mice received daily i.p injections starting 2 days before tumor cell inoculation and continuing during the course of treatment with atorvastatin (10 μg/g body weight/d), celecoxib (10 μg/g/d), a combination of atorvastatin (10 μg/g/d) and celecoxib (10 μg/g/d), or a combination of atorvastatin (5 μg/g/d) and celecoxib (5 μg/g/d). Results: Atorvastatin in combination with celecoxib had stronger effects on growth inhibition and apoptosis of PC-3 cells than either agent used individually. Atorvastatin and celecoxib in combination also had a stronger inhibitory effect on activation of nuclear factor-κB and extracellular signal-regulated kinase 1/2 in PC-3 cells than either agent alone. Treatment of SCID mice with combinations of atorvastatin and celecoxib more effectively inhibited the formation and growth of PC-3 tumors in the mice than either agent administered alone. Conclusions: A combination of atorvastatin and celecoxib had a more potent inhibitory effect on the growth of PC-3 cells cultured in vitro or grown in SCID mice than either agent alone. A combination of atorvastatin and celecoxib may be an effective strategy for the prevention of prostate cancer.