Effects of bisphenol A on the expression of cytochrome P450 aromatase (CYP19) in human fetal osteoblastic and granulosa cell-like cell lines.

The effects of bisphenol A (BPA), an endocrine disruptor, on aromatase (CYP19) expression in human osteoblastic (SV-HFO) and ovarian granulosa-like (KGN) cell lines were examined. CYP19 enzyme activity was suppressed in the presence of BPA in a dose-dependent fashion in both cell lines. CYP19 gene transcript expression, as well as activities of promoter I.4 in SV-HFO and promoter II in KGN, was down-regulated by BPA, suggesting that BPA affects CYP19 at the gene-expression level. These data and the previous finding that BPA induced the down-regulation of promoter I.1 activity within the human placental cell line suggest that there may be a conserved signaling pathway that down-regulates CYP19 expression in response to BPA in both cell lines. Additionally, differences between promoter I.4 and II suggest that there may be cell- and promoter-specific down-regulating mechanisms downstream from the actions of BPA.