Immunohistochemical expression of steroid receptors and glycodelin A in isolated proliferative human endometrial glandular cells after stimulation with tamoxifen and phytoestrogens (genistein and daidzein).

INTRODUCTION: The aims of this study were an evaluation of the distribution patterns of steroid hormone receptors (ER, PR) and glycodelin A (GdA) expression of proliferative endometrial glandular cells after stimulation with tamoxifen (TAM) and phytoestrogens (PE) (genistein, daidzein).
MATERIALS AND METHODS: Human endometrium was obtained from 4 premenopausal women. Glands were stimulated after isolation with single doses of TAM, genistein and daizein (0.1, 1 and 10 mumol/l) and characterised with ER, PR and GdA after 9 days of culture.
RESULTS: ER showed a significant decline with the highest TAM and genistein concentration (p < 0.05), whereas PR increased significantly with TAM and genistein concentrations of 1 mumol/l and 10 mumol/l (p < 0.05). GdA did not show any significant expression under TAM and genistein stimulation. Stimulation with daidzein resulted in no statistically relevant alterations in ER, whereas the PR significantly increased with all three concentrations (p < 0.05) and GdA also showed a significant increase with 1 mumol/l (p < 0.05). DISCUSSION: TAM showed anti-estrogenic properties in premenopausal endometrium. PE showed a similar ER, PR expression pattern as TAM, so therefore PE (genistein and daidzein) could also act as antiestrogens. GdA marked a cell transformation from proliferative to secretory status or the antiestrogen effects of TAM and PE.