Enhanced Fas/CD95-mediated apoptosis by epidermal growth factor in human endometrial epithelial cells

Epidermal growth factor (EGF) has been reported to regulate apoptosis in va rious cell lineages. Throughout the menstrual cycle overexpression of the E GF receptor in the secretory epithelium and constitutive expression of EGF in all types of endometrial cells were identified by immunohistochemical st udy of normal human endometrial tissues. However, it is not known whether E GF also regulates endometrial apoptosis, This study examined the regulatory functions of EGF in endometrial apoptosis by using a human endometrial epi thelial cell line HHUA which is susceptible to Fas-mediated apoptosis. Alth ough EGF alone did not affect the cell growth of HHUA, EGF pretreatment of HHUA enhanced Fas-mediated growth suppression and Fas mediated DNA fragment ation in the cells. Flowcytometric analyses demonstrated that EGF did not i nduce Fas expression on the cell surface while expressions of the EGF recep tor were down-regulated. These results suggest that EGF may enhance apoptot ic susceptibility of the endometrial epithelium, especially in the secretor y epithelium. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.