Marker molecules of human endometrial differentiation can be hormonally regulated under in-vitro conditions as in-vivo

An established cell culture system of isolated human endometrial stromal an d epithelial cells has been used to study the effects of oestrogen and prog esterone, as well as their antagonists, upon endometrial cells. Normal horm onal regulation in vivo was investigated simultaneously in endometrial tiss ue samples taken at different phases of the menstrual cycle. Several marker molecules analysed by immunohistochemistry appeared to depend strongly on endocrine regulation and could be traced in culture. Immunohistochemically, basic parameters of cell biology were identified in vitro, e.g. cell proli feration (Ki-67), adhesion molecules (beta(3) integrin) and paracrine facto rs (leukaemia inhibitory factor), The most reliable parameters to assess ho rmonal influences were oestrogen and progesterone receptor molecules. Immun ohistochemical localization could be improved by molecular biological analy sis lasing RT-PCR. In the presence of oestrogen, a significant expression o f hormone receptors was also Shown by RT-BCR, and withdrawal of oestrogens and addition of gestagen, i.e. medroxyprogesterone acetate, caused receptor downregulation. Addition of the anti-oestrogen ICI 182.780 to cell-culture medium significantly decreased the synthesis of progesterone receptors.