Research Progress in Proliferation Regulation by Progestogen on Endometrial Epithelial Cells

Endometrium is a major target organ of ovarian hormones.After puberty,under the regulation of hypothalamus-pituitary,with cyclical secretion of estrogen and progestogen,endometrial morphology and function also will be changed.In luteal phase,progestogen antagonizes the effect of estrogen to inhibit the proliferation of endometrial epithelial cells,and promotes them to differentiate into secretory cells.Progestogen suppresses proliferation of endometrial epithelial cells and promotes them to differentiation,its mechanism plays a role in two aspects.On the one hand,progesterone can reduce estrogen receptor(ER) expression in endometrial epithelial cells;and reduce the expression and activity of cytochrome P450 aromatase in granulosa cells and increase 17β-HSDII local expression and activity in endometrium for enhancing estrogen metabolism.Thereby,progesterone can indirectly inhibit the proliferation of endometrial epithelial cells.On the other hand,progesterone combines with progesterone receptor,then gets into endometrial epithelial cells' nucleus,regulating expression of cell cycle regulatory proteins,proto-oncogenes and other molecules involved in cell cycle regulation,with directly inhibits the proliferation of endometrial epithelial cells and promotes their differentiation.