Estro-progestinic replacement therapy modulates the levels of basic fibroblast growth factor in post- menopausal endometrium

The levels of basic fibroblast growth factor (bFGF) in human endometrium do not vary during the ovulatory cycle but they increase significantly after menopause (M. Rusnati et al., Growth Factors, 3, 299-307, 1990). Here we report that cyclic estro-progestinic replacement therapy reduces the levels of bFGF in human postmenopausal endometrium to those measured in ovulatory cycle endometrium. Also, we have observed that the levels of bFGF in well-differentiated adenocarcinomas of the endometrium from postmenopausal patients are lower than those detected in their normal counterpart and are comparable to those measured in the normal cycling tissue. The data indicate that the stimulation of cell proliferation induced in postmenopausal endometrium by hormonal therapy or by neoplastic transformation is paralleled by a decrease of endometrial levels of bFGF. This may be due to an increase of the turnover rate of the growth factor in the proliferating versus the quiescent tissue and suggests a role of bFGF in the growth of normal and neoplastic human endometrium. Our data represent the first evidence that sex hormones modulate the levels of biologically active bFGF in vivo.