Differential effects of ambient PAH mixtures on cellular and steroidogenic properties of placental JEG-3 and BeWo cells

We determined the action of a mixture of 16 priority PAHs present in high concentrations in maternal blood (Mix I) and the same but in low concentrations detected in placental tissue (Mix II) on AhR, ER alpha, NF kappa B, CYP1A1, CYP1B1, and COMT protein expression and cell proliferation of JEG-3 and BeWo cell lines. Both mixtures induced AhR expression in JEG-3 and BeWo; however, in JEG-3 cells expression of ER alpha, CYP1A1, CYP1B1, and COMT was upregulated, while in BeWo cells downregulated. The opposite effect of mixtures on NF kappa B protein expression (inhibitory in JEG-3, stimulatory in BeWo) was noted. We suggest AhR-mediated activation of PAHs metabolism in JEG-3 cells, and AhR interaction with NF kappa B and AhR cross-talk with ERa causing inhibition of detoxification in BeWo cells. As a result there was a stimulatory effect on JEG-3 and an inhibitory one on BeWo cell proliferation.