PGR-B is responsible for a proliferative gene signature in ovarian neoplasia in PGR-B expressing mice.

Constitutive PGR-B expression in PGR positive cells in the mouse drives ovarian neoplasia. Chronic treatment with RU486 reduced tumor growth in these PGR-B expressing mice. To further identify how PGR-B functions to promote sustained tumor growth, PGRcre/+ PGR-BLsL/+ mice with ovarian tumors were administered a chronic-release pellet of RU486 or placebo for 24 hours. Tissue was harvested and RNA was isolated. After comparative analyses, it was concluded that PGR-B promotes cell cycle regulatory genes and oncogenic signaling pathways. Pgrcre/+PgrBLsL/+ mice with a tumor size between 0.5-1 cm in diameter were treated with either RU486 or placebo for 24 hours. Tumor tissue was collected for microarray analysis.