Stimulation of ovarian cell proliferation by tetrabromobisphenol A but not tetrachlorobisphenol A through G protein-coupled receptor 30

•TBBPA but not TCBPA stimulates OVCAR-3 and KGN cell proliferation.•TBBPA possesses lower proliferative potency than BPA.•TBBPA and BPA do not modulate GPR30 gene expression.•TBBPA and BPA stimulate cell proliferation through the GPR30 pathway.

Tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) are bisphenol A (BPA) analogs, where the phenolic moieties are substituted with halogens (Br or Cl). Previous studies indicate that BPA has significant proliferative effects on in vitro cultured epithelial ovarian cancer (EOC) cells. Considering this, we analyzed the effects of both TBBPA and TCBPA at 1, 10, and 50 nM on ovarian cancer cell proliferation. The majority of malignant ovarian tumors are epithelial in origin, but approximately 10% are classified as ovarian sex cord tumors, with the most common type being granulosa cell tumors (GCTs). OVCAR-3 and KGN cells were used as in vitro models to represent EOCs and GCTs, respectively. Here, we found that TBBPA, but not TCBPA, stimulated OVCAR-3 and KGN cell proliferation, with lower potency than BPA. The stimulatory effects of TBBPA and BPA on cell proliferation were reversed by pre-treatment with a G protein-coupled receptor 30 (GPR30) antagonist in both cell lines, which possess similar basal GPR30 expression levels. Taken together, our results show for the first time that TBBPA, which has lower potency than BPA, stimulates ovarian cancer cell proliferation through the GPR30 pathway.