Fig. 2. TGF-ß1 treatment decreases nuclear NF-B/Rel binding activity in breast tumor cell lines. In A, NF-B binding. MCF7 and Hs578T (578T) breast tumor cell lines were plated at 1.1 x 104 cells/P100 or 5.6 x 104 cells/P100, respectively, and treated for 3 days with 1 ng/ml TGF-ß1 or carrier BSA solution as control. Nuclear extracts were made and subjected to EMSA using as probe the URE NF-B oligonucleotide. B, NF-B binding. Hs578T breast tumor cell lines were treated with carrier BSA for 48 h (C) or with 1 ng/ml TGF-ß1 for 24 or 48 h, as indicated. Nuclear extracts were prepared and processed as in A. *, a nonspecific band that did not change with TGF-ß1 treatment. C, Oct-1 binding. Hs578T breast tumor cell lines were treated with 1 ng/ml TGF-ß1 for 0, 24, or 48 hrs. Nuclear extracts were prepared and subjected to EMSA for Oct-1 binding.