Figure 7.

Histone modifications associated with active chromatin at the hCYP19I.1 −255 to −155 region increase during syncytiotrophoblast differentiation and are prevented by ICI treatment. Freshly isolated human cytotrophoblasts were cultured in the absence or presence of the ER antagonist ICI 182,780 for either 6 or 18 h. The cells were then treated with 1% formaldehyde and subjected to ChIP analysis using antibodies for acetylated histone H3 Lys 9/14 (A), dimethyl histone H3 Lys 9 (B), or trimethyl histone H3 Lys 9 (C). qRT-PCR was performed using primers to an approximately 100-bp region surrounding the CYP19I.1 ERE-LS. The ChIP data were normalized to input control data and expressed as relative binding units. The results shown are the means ± sem of values from three independent experiments. *, P < 0.05 for untreated vs. ICI-treated cells.