ICI 182,780 stimulates the growth of a uterine cell line derived from p53-deficient mice

UE8 is a uterine epithelial cell line established from p53-deficient fetal female mice. UE8 exhibits a typical epithelial morphology in culture and is strongly positive for cytokeratin, but negative for vimentin in immunocyto chemistry. UE8 shows an active growth in a phenol red free 1:1 mixture of D ulbecco's modified Eagle's medium and Ham's nutrient mixture F-12 supplemen ted with 3% heat-inactivated and dextran-coated charcoal-treated fetal calf serum. Both immunocytochemistry and immunoblot analyses confirmed that UE8 was negative for the estrogen receptor. Diethylstilbestrol added to the me dium at concentrations between 10(-6) and 10(-8) M had no significant effec t on the proliferative rate, and estradiol-17 beta at 10(-6) M was slightly inhibitory. Unexpectedly, however, the "pure anti-estrogen" ICI 182,780 at 10(-6) M significantly enhanced cell proliferation. This is the first obse rvation that the "pure anti-estrogen" ICI 182,780 stimulates the growth of uterine epithelial cells without estrogen receptors.