27-hydroxycholesterol and the expression of three estrogen-sensitive proteins in MCF7 cells

Abstract

The principal aim of this study was to analyze in estrogen receptor-positive MCF7 cells the response of three estrogen-dependent proteins to 27-hydroxycholesterol (27OHC), a major circulating cholesterol metabolite. Immunofluorescence, immunoblotting and immunogold labelling analyses of MCF7 cells exposed for up to 72 h to 2 nM estradiol (E 2) or to 2 μM 27OHC demonstrated similar responses in the expression of MnSOD and ERβ compared to the non-stimulated cells. Thus, the results confirm 27OHC's function as a novel selective estrogen receptor modulator (SERM). The epithelial to mesenchymal transition (EMT), observed in MCF7 cells stimulated for longer than 48 h with 2 μM 27OHC, was accompanied by lower immunoreactive levels of nuclear FOXM1 in comparison to E 2-treated cells. The results presented in this study are discussed taking into consideration the relationship of hypercholesterolemia, 27OHC production, ROS synthesis and macrophage infiltration, potentially occurring in obese pat