MED1 regulates the recruitment of N-CoR and SMRT to TFF1 promoter by tamoxifen. A, MCF-7 and MCF-7/HER2 cells were treated with 100 nmol/L E2, 1 μmol/L TAM or 50 μmol/L AG825 for 45 minutes. The soluble chromatin was then prepared and subjected to immunoprecipitation experiments using control IgG or antibodies against MED1, p-MED1, N-CoR, or SMRT. Immunoprecipitated DNA corresponding to the TFF1 promoter region was amplified and quantified by real-time PCR. B, chromatin immunoprecipitation experiments were carried out as in A by using control scramble or MED1 shRNA treated MCF-7/ HER2 cells.