Hormonal regulation of HSP27 expression in human endometrial epithelial and stromal cells

HSP27 has been analysed immunohistochemically in epithelium and stroma of premenopausal endometria obtained at different stages of the menstrual cycle and in endometria from postmenopausal women receiving oestrogens either alone or in combination with a progestin. The data indicate that HSP27 is increased by oestrogen and inhibited by progestins in glandular epithelium but not stroma. Oestrogen does not increase HSP27 in stromal cells and HSP27 is only present in stromal decidual cells seen in the late secretory phase where it continues to be detectable until the tenth week of gestation. Hormonal regulation of HSP27 is clearly different in endometrial epithelium and stroma and additional regulatory factors may be important as oestrogen alone does not increase postmenopausal epithelial HSP27 to the levels seen in the proliferative phase of premenopausal samples.