TY - JOUR T1 - Combined Treatment of Breast Cancer Cell Lines with Vitamin D and COX-2 Inhibitors JF - Anticancer Research JO - Anticancer Res SP - 1189 LP - 1195 VL - 35 IS - 2 AU - MARC THILL AU - KATHRIN REICHERT AU - ALENA WOESTE AU - STEPHAN POLACK AU - DOROTHEA FISCHER AU - FRIEDERIKE HOELLEN AU - ACHIM RODY AU - MICHAEL FRIEDRICH AU - FRANK KÖSTER Y1 - 2015/02/01 UR - http://ar.iiarjournals.org/content/35/2/1189.abstract N2 - Background: Vitamin D is known for its anti-cancerogenous potential. Prostaglandin E2 (PGE2) is a proliferation and inflammation activating agent. The production of PGE2 is dependent on the activity of cyclooxygenase-2 (COX-2). A link between vitamin D and PGE2 metabolism was recently shown. Materials and Methods: In MDA-MB-231 and MCF-7 breast cancer cell lines we investigated the influence of calcitriol and the COX-2 inhibitor celecoxib regarding cell growth via MTT test, as well as on the protein and mRNA expression of COX-2 using western blot and qRT-PCR. Results: The proliferation of MCF-7 and MDA-MB-231 was inhibited by both calcitriol and the COX-2 inhibitor celecoxib and even stronger by their combination. Moreover, calcitriol inhibited the COX-2 protein expression in MDA-MB-231, as well as the COX-2 mRNA expression in both cell lines. Conclusion: The combination of calcitriol and celecoxib demonstrated a cooperative growth-inhibiting effect in breast cancer cell lines. ER -