ESTROGEN-RECEPTOR EXPRESSION AND THE EFFECTS OF ESTROGEN AND TAMOXIFEN ON THE GROWTH OF HUMAN OVARIAN-CARCINOMA CELL-LINES

To assess the role of oestrogen regulation in the growth of ovarian cancer, we examined the effects of an oestrogen, 17 β-oestradiol, and an anti-oestrogen, tamoxifen, on oestrogen receptor (ER) -positive and -negative human ovarian carcinoma cell lines. As measured by a dextran-coated charcoal adsorption assay, cell lines PEOl, PEO4 and PE06 possessed moderate concentrations of ER (96-132 fmol mg−1 protein), PEA1 and PEA2 had low values (12—23 fmol mg−1 protein) and PE014, TOM, PE023 and PE016 were ER- negative. Addition of 17 β-oestradiol (10 nM or 0.1 nM) to the ER + ve cell line, PE04, increased the growth rate. This oestrogen stimulation could be blocked by 1 μM tamoxifen. In contrast, the growth rate of the ER —ve cell line PEOl4 was unaffected by the addition of 17 β-oestradiol or tamoxifen. Concentrations of tamoxifen in excess of 8 μm were required to produce complete cytostasis in all lines. This concentration of tamoxifen over 72 hours also inhibited 50% colony formation when cells were plated on plastic. These data indicate that some ovarian carcinoma cell lines contain ER and their growth can be sensitive to oestrogen and anti-oestrogen modulation. © The MacMillan Press Ltd., 1990.