Linifanib associated with poor prognosis . Recent results indicate that antagonism of EP 4 may be as effective as COX inhibition . EP 2 and EP 4 may be critical determinants in cancer cell behaviour in breast cancer. Experiments with prostate cancer cells have shown that calcitriol acts in multiple pathways to inhibit cell proliferation . This leads to a possible regulation of PG levels and PG actions by calcitriol and inhibition of the stimulation of prostate cancer cell proliferation by endogenously derived PGs. The three following mechanisms are involved: suppression of COX-2 expression, upregulation of 15-PGDH expression, and reduction of mRNA expression of the PGE 2 receptor subtype EP 2 and the PGF 2 α receptor FP .

VDR expression is found in healthy breast tissues and in more than 80% of breast cancer  Sympatol tissues . The natural ligand of the VDR, 1,2 D 3 , and its analogues inhibit cell proliferation and induce apoptosis in breast cancer cell lines . This was also shown for animal models . A significantly lower VDR expression in western blot analysis was observed in our breast cancer tissue samples. This is in line with our own published data for breast cell lines . Compared to other groups, an inconsistency in results is reported for studies evaluating cell lines and tissues . Townsend et al. detected a 7-fold increase of VDR mRNA level by RT-PCR in breast cancer . This might be due to post-transcriptional modifications of VDR mRNA on its way to functional protein .

Our results show an inverse correlation of COX-2 and 15-PGDH protein levels, as well as  purchase AZD2171 the VDR protein level. This is in line with our findings in MCF-10F and MCF-7 cell lines where we also detected an inverse correlation of COX-2 and VDR protein expressions. These findings suggest a possible link between the VDR, associated target genes and PG metabolism . Thus, we suggest that a growing body of evidence exists regarding a possible link between PG and the vitamin D metabolism in cancer. Several studies suggest overexpression of COX-2 due to increased proliferation, reduced apoptosis and enhanced mediation of neoangiogenesis and chemoresistance in ovarian cancer . But the data is inconsistent. Although some studies detected COX-2 expression wavelength other studies observed a more frequent COX-1 expression .

There are also results that suggest COX-1 overexpression to be a stimulus in ovarian  order FTY720 carcinoma tumor growth . But these findings seem not to have any prognostic relevance . Thus, our analysis of tumor samples from 13 patients is Cordes et al : Serum PGE 2 and Vitamin D Receptor Levels in Breast and Ovarian Cancer in line with the literature, as we detected a significantly higher COX-2 expression in the malignant tissues. Measurement of circulating 2 D 3 levels in serum is considered to be an excellent measurement of the availability of vitamin D from the diet and supplements, and from synthesis in the skin . It is of potential importance in breast carcinogenesis due to the fact.