REGULATION OF HUMAN CHORIONIC-GONADOTROPIN SECRETION AND MESSENGER-RIBONUCLEIC-ACID LEVELS BY FOLLISTATIN IN THE NUCC-3 CHORIOCARCINOMA CELL-LINE

NUCC-3 choriocarcinoma cell line was used as an in vitro placental cel l model to investigate the effects of follistatin on GnRH-stimulated h CG secretion and its subunit mRNA level and stability. Follistatin alo ne did not affect basal hCG secretion and its subunit mRNA level. GnRH increased hCG secretion and hCG beta-mRNA level in a dose-dependent m anner. Follistatin significantly suppressed GnRH-stimulated hCG secret ion and hCG alpha- and beta-mRNA level. It inhibited hCG secretion in response to PMA, and did not affect the stability of hCG alpha- and be ta-mRNA. The authors suggest that follistatin inhibits GnRH-stimulated hCG secretion as well as hCG alpha- and beta-RNA level by decreasing the rate of transcription through the second messenger transduction sy stem-protein kinase-C.