Effects of plasticisers and related compounds on the expression of the soluble form of catechol-O-methyltransferase in MCF-7 cells

Previously we have shown that E2 down regulates S-COMT expression. Here the effects of four phthalate esters and 4-(tert-octyl) phenol on the intra-cellular levels of S-COMT and COMT activity were studied in MCF-7 cells as a measure of estrogenic activity of these compounds. The four phthalate esters caused significant reductions in both S-COMT protein and COMT activity levels. These effects were inhibited by the ER receptor antagonist ICI182780. 4-(tert-octyl) phenol also caused reductions in these parameters, but the effects were not abolished by ICI182780. Assay of S-COMT protein levels represents a simple and convenient method of assessing the estrogenic potential of a compound.