Background: Breast cancer is associated with inflammatory processes based on an up-regulation of cyclooxygenase-2 (COX-2) expression. The antiproliferative effects of calcitriol (1,25(OH)2D3) mediated via the vitamin D receptor (VDR) render vitamin D a promising target in breast cancer therapy. First data suggest a correlation between vitamin D and prostaglandin metabolism. Materials and Methods: We determined the expression of VDR, COX-2, 15-PGDH and the prostaglandin receptors EP2/EP 4 in normal and malignant breast tissue by real-time PCR and Western blot analysis, as well as 25(OH)2D3 and PGE2 plasma levels from healthy and breast cancer patients. Results: Significantly higher COX-2, lower VDR and lower EP2 and EP4 receptor protein levels in the malignant tissue and a significantly lower 15-PGDH protein level in normal breast tissue were detected. Breast cancer patients older than 45 years, diagnosed and sampled in the wintertime had significantly lower 25(OH)2D3 and higher PGE2 serum levels. Conclusion: The inverse correlation between VDR and both COX-2 and 15-PGDH, as well as between PGE2 and 25(OH)2D3 levels, suggests a possible link between VDR-associated target genes and prostaglandin metabolism.
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|Published - 05.2010