Regulation of human chorionic gonadotropin synthesis in cultured human placental cells by glucocorticoids.

The synthesis of hCG and its subunits in temperature-sensitive, simian virus 40 tsA mutant-transformed human first trimester and term placental cells and in choriocarcinoma cells was studied in the presence and absence of glucocorticoid hormones. The tsA-transformed placental cells were studied at 33 C (the temperature at which the cells exhibit the transformed phenotype) and at 40 C (the temperature at which the cells regain their differentiated nontransformed phenotype). The glucocorticoids cortisol and dexamethasone did not affect the synthesis of hCG or hCG alpha in either transformed term placental cells or choriocarcinoma cells. In the tsA-transformed first trimester placental cells, however, glucocorticoids greatly inhibited hCG synthesis but induced hCG alpha synthesis. The inhibition on hCG synthesis was immediate, stronger at 40 C than at 33 C, and independent of the growth stage of the cells. The glucocorticoid effects were specific; neither estradiol nor progesterone affected the synthesis of hCG or hCG alpha. Furthermore, progesterone did not block the action of the glucocorticoid. These selective effects in cultured first trimester placental cells suggest that glucocorticoids may play an important role in the regulation of hCG production during early pregnancy.