Characterization of a temperature-sensitive beta-endorphin-secreting transformed endometrial cell line

An endometrial cell line (HRE-H9) was established and characterized to study the mechanism by which gene expression of POMC-derived peptides is controlled in uterine tissues. The HRE-H9 cell line was isolated by transforming primary rabbit endometrial cell cultures, derived from hCG-treated pseudopregnant rabbits, with a temperature-sensitive A209 mutant (tsA209) simian virus 40 at a permissive temperature (33 C). The resulting cells exhibited temperature sensitivity in growth and synthesis of immunoreactive beta-endorphin (ir-beta END). The ir-beta-END present in the cell extracts and culture media was assayed by a specific beta END RIA. Sephadex G-50 gel filtration chromatography of the transformed cell extracts showed three peaks of beta END immunoreactivity. The first peak eluted at the void volume, the second peak coeluted with the beta-lipotropin standard, and the third peak coincided with the porcine beta END standard, ir-beta-END was also detectable in endometrial culture media, suggesting that the transformed endometrial cells secreted POMC-derived peptides. Our data indicate that the tsA209 mutant virus-transformed endometrial cell line provides a suitable model for study of the synthesis and regulation of POMC-derived peptides in extrapituitary tissues.