Abstract
Human diploid fibroblasts in culture were examined for production of glycopeptide hormones. Forty‐one percent of the strains produced human chorionic gonadotropin (hCG) under normal growth conditions. Constitutive hCG synthesis was apparently unrelated to donor age, length of time in culture, or number of passages. Follicle stimulating hormone (FSH) was not found in any strain investigated. Only one cell strain produced free α‐chains of glycopeptide hormones. Hydroxyurea (HU) at a concentration of 1 mM mediated a small, statistically significant increase in hCG production (p < 0.01) in all constitutive strains, but had no effect on non‐hCG‐producing fibroblast strains. Sodium butyrate (Bu) was effective in increasing hCG synthesis in only one constitutive strain, derived from a newborn foreskin. HU treatment had no apparent effect on cell structure. All Bu‐treated strains, both those producing hCG and the nonproducers, showed morphological alterations; cells were flattened and they contained ordered arrays of refractile granules. It is suggested that hCG synthesis in cultured human diploid fibroblasts may result from a localized chromosomal event in which the loci responsible for this hormone are activated. Human diploid fibroblasts in culture are shown to be amenable to the study of gene expression and its modulation.