17beta-oestradiol-induced gene expression in cattle prostate: biomarkers to detect illegal use of growth promoters.

The effects of 17beta-oestradiol (E2) on gene expression in cultures of bovine primary prostate stromal cells (BPSCs) and prostate gland tissue were studied. In the first part of the study, BPSCs were grown in the presence of E2 from the first passage to the end of the experiment; a second group was treated in the same way but the treatment was suspended for 48 hours before the end of the experiment; a third group of BPSCs served as a control. In the second part of the study, five male veal calves, aged 130 days, were treated four times intramuscularly with 10 mg of E2 at intervals of two weeks and then euthanased two weeks after the last treatment. Quantitative PCR and immunohistochemistry were used to evaluate the expression of fibroblast growth factor (FGF) receptors (FGFRs), FGFs, progesterone receptor, androgen receptor and oestrogen receptor in BPSCs and prostate tissue. E2 induced a significant over-expression of progesterone receptor in both BPSCs and prostate tissue. There was also a marked up-regulation of FGFR types 1, 2 and 3 genes observed in the BPSCs.