Role of growth factors in the human endometrium during aging

The aim of this study was to investigate the possible role of epidermal growth factor (EGF) and of insulin-like growth factor-I (IGF-I) in physiological and pathological changes of the endometrial tissue during aging. Thirty-four patients undergoing hysterectomy were divided into three groups: (A) premenopausal women with regular menses, (B) pre-menopausal women with irregular bleeding and (C) post-menopausal women. Endometrial samples were collected after the removal of uterus and were used for immunohistochemical evaluation of EGF, EGF receptor (EGFr) and IGF-I and also for Northern blot analysis of IGF-I gene expression. Plasma levels of 17 beta-oestradiol (E2), D4-androstenedione (D4-A) and oestrone (E1) were also assayed. The immunohistochemical scores (HSCORES) for EGF, EGFr and IGF-I were significantly higher in groups A and B than in group C. Independently from the menstrual history, significantly higher HSCORES of EGF, EGFr and IGF-I were present in hyperplastic endometrium than in those which were proliferative and atrophic. Moreover, IGF-I mRNA expression was observed in all pre-menopausal women, whereas only 1 post-menopausal women with hyperplastic endometrium showed detectable RNA encoding for IGF-I. Higher levels of D4-A were also significantly correlated (P < 0.05) with higher HSCORES of EGF, EGFr and IGF-I. Our results suggest that the above mentioned growth factors could act as mediators of oestrogens on the endometrial functional activity.