SMAD3 and SOX4 binding profiling in human breast cell lines

In order to identify genes co-bound by SOX4 and SMAD3 in the context of breast cancer, different breast cell lines (HMLEs, MDA-MB-231 or HCC-1954) were used. Due to low endogenous expression levels for SOX4 in HMLEs in untreated conditions, doxycycline-dependent SOX4 overexpression was obtained by transducing HMLE cells with pIINDUCER21-SOX4 vector..Cells were plated and SOX4 and SMAD3 chromatine-immunoprecipitation was performed in untreated conditions, TGF-beta (2.5ng/ml), doxycycline (0.5ug/ml) or both as indicated. Genome-wide binding sites for SOX4 and SMAD3 was identified in HMLEs, MAD-MB-231 and HCC-1954 cells. SOX4 and SMAD3 ChIP-sequencing of different human mammary cells in the presence and absence of TGF-β