Induction of human follicle-stimulating hormone in HeLa cells by sodium butyrate

THE ectopic production of polypeptide hormones by tumours derived from tissues that normally do not synthesise these proteins provides a means for investigating regulation of gene expression. All of the hormones ectopically synthesised by non-endocrine tumours are polypeptides or prostaglandins; however, pituitary gonadotropin production by neoplasm as opposed to chorionic gonadotropins is apparently very rare1. Only one patient has been reported in which a bronchiogenic carcinoma produced follicle-stimulating hormone (FSH) and luteinising hormone (LH) (ref. 2). Glycopeptide hormones—FSH, LH, thyroid-stimulating hormone (TSH) and human chorionic gonadotropin (HCG)—are composed of two dissimilar subunits: an α subunit that is common to all the glycopeptide gonadotropic hormones and a β subunit unique for each hormone that confers biological specificity3. It has been shown that HeLa cells, derived over 25 yr ago from a carcinoma of the cervix, secrete HCG (refs 4,5) and the free α subunit of glycopeptide hormones6. Synthesis of HCG (ref. 4) and the α subunit5 is markedly increased by growth in medium with sodium butyrate. We report that HeLa cells also produce pituitary FSH which is induced by butyrate. The surprising synthesis of FSH by a non-pituitary cell has required validation of the radioimmunoassay (RIA) to exclude cross-reaction with other gonadotropic hormones.