Differences in ß-catenin and nuclear factor ?B (NF-?B) levels depending on hormones in endometrium cells

In this study, in in-vitro endometrial cell model, estrogen and progesterone dependent endometrial cycle stages and ß-catenin and nuclear factor ?B (NF-?B) signaling pathways in terms of human chorionic gonadotropin (HCG) hormone that is synthesized by syncytiotrophoblast cells, and changes in the cell proliferation are examined immunocytochemically.To assess cell proliferation, S-phase specific marker bromodeoxyuridin (BrdU) immunocytochemistry was performed. While an increase in BrdU incorporation was observed after estrogen incubation, there was no change seen in cell proliferation rates after progesteron and HCG applications. In endometrial cells, distinct ß-catenin expression was observed across the entire intracellular margin of the plasma membrane. After incubation with estrogen and progestogen, no change in the expression of existing ß-catenin was noticed. Also, a significant decrease was observed in membrane-bound ß-catenin expression after incubation with HCG. Compared with estrogen and HCG treated experimental cell group, NF-?B activity was found similar to that of the control cell group. On the other hand, in the progesteron treated group, an increase was observed in cytoplasmic NF-?B expression.As a result of our study, S-phase specific marker BrdU-positive cell ratio which is increased by estrogen incubation was found compatible with cycle stages under the control of estrogen hormone. It was determined that the expression of plasma membrane localized cell adhesion molecule ß-catenin was decreased by the effect of hormone HCG. Besides playing a role in inflammation control and interacting with steroids, it was decided that NF-?B expression was related with progesteron hormone; on the other hand it was independent from HCG, which is produced by syncytiotrophoblasts.