Sex hormones modulate the synthesis of basic fibroblast growth factor in human endometrial adenocarcinoma cells: Implications for the neovascularization of normal and neoplastic endometrium

Abstract

Basic fibroblast growth factor (bFGF) has been demonstrated to exert an angiogenic activity in vivo. Here, the ability of bFGF to stimulate plasminogen activator (PA) production in bovine capillary endothelial cells was used as an assay for the presence of bFGF‐like molecules in the extracts of the human endometrial adenocarcinoma AN3CA, HEC‐1‐A, and HEC‐1‐B cell lines. The identity of the PA‐stimulating activity with bFGF was confirmed by its high affinity for heparin and by its cross‐reactivity with antibodies to human placental bFGF. Western blot analysis and immunoprecipitation experiments showed that, in the extracts of the three cell lines, these antibodies recognize a protein with an apparent molecular weight of ∼ 17,000 daltons. 17β‐Estradiol stimulates the synthesis of this bFGF‐like molecule in all the endometrial cell lines tested. This stimulation can be abolished by treating the cells with progesterone. These data demonstrate the capacity of sex hormones to regulate bFGF synthesis in tumor endometrial cells, and they suggest that bFGF may play a role in the vascularization of the endometrial adenocarcinoma as well as of the normal endometrium.