Characterization of steroid production in cultured human choriocarcinoma cells.

Progesterone is the major steroid synthesized by the JEG-3, BeWo, and JAR cell lines of choriocarcinoma. A lesser amount of pregnenolone is produced. The 17alpha-hydroxy derivatives of these steroids are only minimally present in three lines. The addition of fetal calf serum to the culture medium modestly increases the synthesis of these steroids, but increases the quantity of 17beta-estradiol produced by 30- to 90-fold. The addition of dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, androstenediol, and testosterone was shown to stimulate 17beta-estradiol synthesis. There is a clear dose-response relationship between the amount of testosterone added and the quantity of 17beta-estradiol produced. These results indicate that 3beta-hydroxysteroid dehydrogenase-isomerase, 17beta-ol dehydrogenase, and aromatase are active in cultured choriocarcinoma cells, whereas 17beta-hydroxylase and 17-20 desmolase do not appear to be functional in these cells. It is concluded that the stereoidogenic capabilities of choriocarcinoma cells in culture are similar to those of the in vivo placenta and support their use as an experimental model of placental steroidogenesis.