Female article controlled study human human cell Humans cell proliferation nonhuman priority journal progesterone receptor Animals Cell Proliferation Medroxyprogesterone Acetate Mice Mice, Inbred BALB C Receptors, Progesterone Tumor Cells, Cultured animal experiment animal model animal tissue breast cancer cancer cell culture cancer growth drug effect drug receptor binding enzyme activation female mouse protein expression 17(13-18)abeo 5alphah pregna 2,13,15,17 tetraen 1,20 dione