INFLUENCE OF GROWTH-FACTORS ON PROLIFERATION AND MORPHOGENESIS OF RABBIT OVARIAN MESOTHELIAL CELLS IN-VITRO

The ovarian mesothelium (OM) is the source of one of the most frequent and lethal types of common ovarian epithelial tumors, the so-called p apillary serous carcinomas. Recent work from our laboratory indicates the existence of postovulatory luteal OM mitogens with variable affini ty for heparin. To further investigate the paracrine regulation of thi s ovarian tissue, rabbit ovarian mesothelial cells (OMC) were cultured in serum-free, fibronectin-rich HL-1 medium with or without one of th e following luteal growth factors (0.1, 1, and 10 ng/ ml): basic (bFGF ) and acidic (aFGF) fibroblastic growth factors, epidermal growth fact or (EGF), transforming growth factors alpha (TGF alpha) and beta (TGF beta), tumor necrosis factor alpha, platelet-derived growth factor (PD GF-BB), and vascular endothelial growth factor. After 8 days of cultur e, OMC growth was stimulated 3-fold by all tested doses of bFGF, EGF, and TGF alpha and 2-2.5-fold by 10 ng/ml of PDGF-BB and aFGF; it was i nhibited more than 60% by TGF beta (10 ng/ml). In addition to enhancin g the formation of cohesive OMC monolayers, most factors enhanced 3- t o 6-fold the aggregation of OMC into papillary processes. The finding of a growth and morphogenetic response to intraluteal growth factors i s novel and suggests a role for postovulatory paracrine regulation of OM pathobiology.