Fig. 1.

Ovarian cancer cell lines express membrane progesterone receptor (mPR) mRNA and protein. a qPCR identified and compared gene expression levels of each mPR isoform (α, β, and γ) in a panel of ovarian cancer cell lines relative to control MCF-7 breast cancer cells (mean ± SD, n = 3). b Immunoblot analysis defined protein expression of mPRα in the SKOV-3 and ES-2 ovarian cancer cell lines relative to control MCF-7 breast cancer cells. SKOV-3 and ES-2 cells do not express nuclear progesterone receptor (n-PR-A or -B) protein. c OVCAR-3 ovarian cancer cells transiently transfected with a n-PR-specific PRE-luciferase reporter construct only respond to stimulation with the n-PR specific ligand R5020 (10 nM) for 18 h when co-transfected with a n-PR-B overexpression construct (mean ± SD, n = 3; NS, not significant; asterisk, p ≤ 0.05; all firefly luciferase values are individually normalized to the expression of a Renilla-based luciferase reporter construct serving as an internal control)