After hormone treatment, the medium was replaced by medium containing 1% formaldehyde and incubated 10 min at 37ºC for cross-linking. The reaction was stop by adding 125 mM glycine and incubated 5 min at room temperature. Cells were washed twice with cold PBS, and collected. Preparation of chromatin and ChIP experiments were performed as previously described (Strutt et al, Methods Mol Biol. 1999; 119:455-567). Immunoprecipitated DNA was purified by phenol:chloroform followed by ethanol precipitation It was performed using the NEBNext DNA sample prep Reagents set 1