Steroid metabolism in human teratocarcinoma cell line PA 1

Abstract

Human ovarian teratocarcinoma cells of line PA 1, (Zeuthen et al., 1979[1]) used as model for early embryonic cells, were analyzed for their in vitro capacity to convert steroids. The cells were incubated for 20 h with radioactive pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone or estradiol-17β, or with non-radioactive progesterone, 6α- or 6β-hydroxyprogesterone, 3β-hydroxy-5αa-pregnan-20-one, dehydroepiandrosterone or estradiol-17β. The metabolites were analyzed by thin layer chromatography or studied by gas chromatography-mass spectrometry. The results indicate that PA 1 cells are able to metabolize, although to a restricted amount, a variety of steroids, most markedly progesterone. The metabolites were almost exclusively found in the medium. The main metabolite of progesterone was 3β,6α-dihydroxy-5α-pregnan-20-one. Minor formation of progesterone from pregnenolone could be detected. Human chorionic gonadotropin did not have any effect on pregnenolone metabolism. No formation of estradiol-17β or estrone from dehydroepiandrosterone, androstenedione or testosterone could be detected. However, estradiol-17β was shown to be converted mainly to estrone. These findings indicate that undifferentiated PA 1 teratocarcinoma cells like certain mouse teratocarcinoma cells, seem not be be steroidogenic but are capable of metabolizing naturally occurring steroid hormones and their precursors.