Fig. 3: MUC1-C regulates ER coactivator MED1 by a CDK7-mediated mechanism.

a Nuclear lysates from MCF-7 cells treated with 100 nM 17β-estradiol (E2) for 3 h were precipitated with anti-MUC1-C or a control IgG. The precipitates and input lysate were immunoblotted with antibodies against the indicated proteins. b Nuclear lysates from MCF-7 cells treated with 100 nM E2 for 3 h were precipitated with anti-MED1 or a control IgG. The precipitates and input lysate were immunoblotted with antibodies against the indicated proteins. c, d Lysates from MCF-7/tet-MUC1shRNA and T47D/tet-MUC1shRNA cells treated with vehicle or DOX for 5 days were immunoblotted with antibodies against the indicated proteins. e GSEA of RNA-seq data from MCF-7 and T47D cells with MUC1-C silencing using the UDAYAKUMAR MED1 TARGETS UP gene signature. f MCF-7/CshRNA, MCF-7/MED1shRNA#1 and MCF-7/MED1shRNA#2 cells were analyzed for MED1, ESR1, TFF1, MYB, and BCL2 transcripts by qRT-PCR. The results (mean ± SD of four determinations) are expressed as relative levels compared to that obtained for CshRNA cells (assigned a value of 1). g MCF-7/CshRNA, MCF-7/MED1shRNA#1 and MCF-7/MED1shRNA#2 cells were analyzed for colony formation. Shown are representative photomicrographs of stained colonies (left). The results (mean ± SD of three determinations) are expressed as relative colony formation compared to that for CshRNA cells (assigned a value of 1) (right).