Comparative Immunofluorescent Analysis of Estrogen Receptor Beta Expression in Ovarian and Breast Cancer Cell Lines

Comparative quantitative evaluation of estrogen receptors β (ERβ) expression is performed by the immunofluorescence method using flow cytometry in the ovarian cancer cell lines COLO-704, OVCAR-3, EFO-21, and SK-OV-3, as well as the breast cancer cell line MCF-7. A high level of ERβ expression (88–91%) is revealed in all the cell cultures investigated, and significant differences were observed in the intensity of the marker’s expression between ovarian cancer cell cultures (in OVCAR-3, EFO-21, and SK-OV-3 they are higher than in COLO-704 cells by factors of 1.6, 2.3, and 3.5, respectively). Moreover, the intensity of ERβ expression was significantly higher in SK-OV-3, EFO-21, and OVCAR-3 than in MCF-7 cells: in 2.7; 1.4 and 1.9 times, respectively. The authors suggest that in contrast to breast cancer patients, ERβ rather than ERα could be the main target for antiestrogens in ovarian cancer patients. The revealed differences in the ERβ expression in a number of widely used ovarian cancer cell cultures lead us to recommend them for further fundamental research on ERβ to study the biological effects of antiestrogens.