Human Reproduction vol.8 no. 1 pp.11 —16, 1993 Immunohistochemical localization of acidic and basic fibroblast growth factors in normal human endometrium and endometriosis and the detection of their mRNA by polymerase chain reaction R.A.Ferriani 1 , D.S.Charnock-Jones 1 , A.Prentice 1 , E.J.Thomas 2 and S.K.Smith 13 Department of Obstetrics and Gynaecology, 'University of Cambridge and 2 University of Southampton, Southampton, Hants, UK 3 To whom correspondence should be addressed at: Department of Obstetrics and Gynaecology, University of Cambridge, The Rosie Maternity Hospital, Cambridge CB2 2SW, UK Growth factors play a role in the cyclical growth and vascularization of normal endometrium. Abnormal endometrial proliferation and neovascularization may result in endometriosis. This study determines the presence and localization of acidic and basic fibroblast growth factors (aFGF and bFGF respectively) in endometrium of normal women, and in normal and ectopic endometrium of women with endometriosis. Endometrium was obtained at curettage or hysterectomy for benign disease, or laparoscopy for endometriosis. aFGF- and bFGF-immunoreactivity was detected at different phases of the menstrual cycle by immunohistochemistry using primary polyclonal rabbit antibodies. Expression of mRNA for aFGF and bFGF was determined in normal endometrium by nested reverse trans- criptase polymerase chain reaction (RT-PCR). aFGF- and bFGF-immunoreactivity were both detected in endometrium from normal women, and in normal and ectopic endometrium of women with endometriosis. The pattern of staining with the two different FGFs was the same: immunoreactivity was predominantly confined to glandular epithelial cells and did not change throughout the menstrual cycle. Little or only light staining was seen in stromal cells and myometrium, and the pattern of staining did not differ between endometriotic and normal tissue. The presence of mRNA for aFGF and bFGF was demonstrated in normal endometrium. The detection of aFGF and bFGF mRNA in normal endometrium and aFGF- and bFGF-immunoreactivity in normal and endometriotic tissues suggests that these peptides may play a role in the proliferation and angiogenesis of normal and ectopic human endometrium. Key words: endometrium/endometriosis/growth factors/immuno- histochemistry/polymerase chain reaction Introduction Proliferation and repair of human endometrium after menstru- ation is a prerequisite for implantation and development of the fertilized ovum. To complete this function, endometrium undergoes cyclical proliferation and differentiation of both epithelial and stromal cells and neovascularization (Noyes et al., 1950; Weitlauf, 1988). The paracrine and autocrine factors regulating this growth are poorly understood, although these modifications were assumed to be related to cyclical changes in circulatory levels of ovarian steroids. Recently, diverse growth factors have been associated with regulatory mechanisms of the female reproductive tract, and growth factors may mediate the oestrogen-stimulated growth response (Presta, 1988; Haining et al., 1991a,b; Irwin etal, 1991; Nelson etal, 1991). Fibroblast growth factors (FGFs) are a family of at least seven structurally related peptides with high affinity for heparin (Gospodarowicz et al., 1987; Rifkin and Moscatelli, 1989). The most intensively studied members of the family are acidic FGF (aFGF) and basic FGF (bFGF), which have 55% sequence homology and a similar spectrum of biological activity, with bFGF being 30 times more potent than aFGF (Gospodarowicz et al., 1987). Both growth factors promote mitogenesis and differentiation of a wide variety of neuroectodermal and meso- dermal cells, and are associated with haemostasis, angiogenesis, tissue repair, embryonic development and tumorigenesis (Gospodarowicz etal., 1987; Rifkin and Moscatelli, 1989). bFGF is present in a number of cultured cell types, normal tissues and tumours (Gospodarowicz et al., 1987; Folkman et al., 1988; Cordon-Cardo et al., 1990; Gonzalez et al., 1990) and its mRNA has been cloned from human cDNA libraries (Abraham et al., 1986). Evidence that bFGF may be involved in endometrial function includes the identification of angiogenic molecules in rabbit endometrium (Lynch et al., 1986), and the identification of bFGF in porcine (Brigstock et al., 1990) and human uterus (Cordon- Cardo et al., 1990; Rusnati et al., 1990). Recombinant bFGF stimulates plasminogen activator production in normal endo- metrium and endometrial adenocarcinoma cell lines (Presta, 1988; Rusnati et al., 1990) and stimulates proliferation of human endometrial stromal cells (Irwin et al., 1991). Ovarian steroid hormones modulate the synthesis and function of bFGF in endometrial cells (Presta, 1988; Irwin et al., 1991), suggesting that these growth factors may play a role during the cyclical growth and vascularization of endometrium. Abnormal endo- metrial proliferation and neovascularization within the peritoneal cavity may result in endometriosis (Smith, 1991) and bFGF has not previously been described in endometriosis. There are fewer studies of aFGF. aFGF is less well conserved between different species, and Southern blotting analysis of human genomic DNA shows one gene for each growth factor (Mergia et al., 1986). aFGF is found predominantly in brain and retina (Bohlen et al., 1985), whilst capillary endothelial cells that © Oxford University Press 11 Downloaded from https://academic.oup.com/humrep/article/8/1/11/667336 by guest on 18 November 2021