Figure 4.

Progesterone receptor is required for cervical cancer prevention by medroxyprogesterone acetate (MPA). A: Treatment regimens are depicted. All mice were treated with estrogen (E₂) until end points (6 or 8 months). Arrowheads indicate monthly injections with MPA. B: MPA induces hypoplasia only in Pgr-positive mice. Shown are high-magnification images of representative hematoxylin and eosin (H&E)-stained cervical epithelia from each genotype. C: Cervical sections were stained with Alcian blue. Nuclei were counterstained with nuclear fast red. Scale bars = 50 μm.