Production of pregnancy-associated plasma protein-A (PAPP-A) by cultured tumour granulosa cells.
Ten ovarian and 2 cervical tumour cell lines were analysed for the production of pregnancy-associated proteins. Pregnancy-associated plasma protein-A (PAPP-A) was detected by radioimmunoassay in culture media of 2 out of 4 (50%) tumour granulosa cell lines (mean = 104 microIU/10(5) cells/24 h) but not in any ovarian (n = 6) or cervical (n = 2) tumour cell lines. By contrast, human chorionic gonadotrophin (hCG), pregnancy specific beta 1-glycoprotein and alpha-fetoprotein (AFP) were not detected in any of the PAPP-A positive media. Only two cell lines produced hCG (58.5 and 25.5 mIU/10(5) cells/24 h). No AFP was produced by any of these 12 cell lines, whereas placental protein 5 was positive in 7. None of these proteins were detected in the culture media of 4 cell lines. In vitro derived PAPP-A was immunologically indistinguishable from either pregnancy or ovarian follicular PAPP-A. All PAPP-A species interacted reversibly with immobilised heparin and were determined by molecular sieve chromatography to have an apparent molecular weight of 820,000 daltons. Cultured tumour granulosa cells specifically synthesised and secreted a large protein which was immunologically and physicochemically indistinguishable from in vivo (pregnancy and ovarian follicular) derived PAPP-A.
D005260:Female; D006106:Granulosa Cell Tumor / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight; D010051:Ovarian Neoplasms / Q000378:metabolism*; D011257:Pregnancy Proteins / Q000096:biosynthesis*; D011266:Pregnancy-Associated Plasma Protein-A / Q000096:biosynthesis*; D011485:Protein Binding; D012685:Sepharose / Q000031:analogs & derivatives / Q000378:metabolism
D011257:Pregnancy Proteins; C037405:heparin-sepharose; D006493:Heparin; D012685:Sepharose; D011266:Pregnancy-Associated Plasma Protein-A