Effects of estradiol on proliferation of endometrial adenocarcinoma cells (Ishikawa line).
Estradiol (E2) stimulates the proliferation of human endometrial adenocarcinoma cells of the Ishikawa line, which had been previously shown to respond to estrogen by increasing their levels of progesterone receptor and the specific activities of DNA polymerase alpha and alkaline phosphatase. Although E2 (10(-8) M) did not increase rates of proliferation during the initial logarithmic growth period of the cultures under the chosen experimental conditions (MEM with 15% charcoal-treated fetal bovine serum renewed every 2-3 days), it sustained cell proliferation after about day 10, when parallel control cultures had reached plateau cell densities. Cell proliferation in control cultures at plateau levels was resumed when the hormone was added. Growth rates of cultures containing E2 from the time of seeding and the proportion of quiescent cells, estimated by using a simple cell kinetic model, decreased steadily with time. Ornithine decarboxylase and DNA polymerase alpha activities, as well as estrogen receptor levels, also decreased with time in culture. Ishikawa cells formed colonies in soft agar; colony formation efficiencies were higher as the number of cells seeded was increased from 10,000 to 100,000 cells/6 cm dish, were not influenced by the addition of E2 to the medium (10(-9) to 10(-5) M) and were markedly reduced by difluoromethylornithine (10(-2) M), an effect that was counteracted by putrescine (25 X 10(-6) M).
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004257:DNA Polymerase II / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007700:Kinetics; D008433:Mathematics; D008954:Models, Biological; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D014594:Uterine Neoplasms / Q000378:metabolism / Q000473:pathology*
D011960:Receptors, Estrogen; D004958:Estradiol; D004257:DNA Polymerase II; D009955:Ornithine Decarboxylase