Fig. 1.

TβRIII expression correlates with NFκB signaling in MCF10A and MDA-MB-231 cells. (A) Cell surface expression of TβRIII in MCF10A and MDA-MB-231 cells was demonstrated by binding and cross-linking assay as described in Materials and Methods. Both total cell lysate and immunoprecipitates with anti-TβRIII antibody (820) were analyzed. For the immunoprecipitates, densitometry of TβRIII expression controlled for β-actin is presented below. (B and C) Cells were transfected with pNFκB-Luc (B) or p3TP-Luc (C) and pRL-SV40 using Fugene 6 and grown for 24 h. Cells were treated with buffer, TGF-β1 (100 pM) or TGF-β2 (200 pM) for 24 h and harvested for luciferase activity assay. Data are expressed as means ± SDs of at least three independent experiments. Statistical significance of differences was assessed using unpaired Student's t-tests (*P < 0.01). (D) Subconfluent cells were treated with TGF-β1 (200 pM) for the indicated times and harvested for western blotting with the indicated antibodies. The results shown are representative of at least three independent experiments.