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. Author manuscript; available in PMC: 2017 Feb 15.
Published in final edited form as: Mol Cell Endocrinol. 2015 Dec 13;422:160–171. doi: 10.1016/j.mce.2015.11.033

Fig. 7.

Fig. 7

Antibody-mediated IGFBP-1 neutralization or IGFBP-1 knockdown reverses the inhibition of IGF-1 stimulation in 4-OHT-treated MCF-7 cells. (A) Two hours prior to IGF-1 stimulation (15 minutes), control IgG or IGFBP-1 neutralizing antibody (10 ng/mL each) were added to MCF-7 cells treated with vehicle (V) or 4-OHT-treated for 24 hours. Total AKT and phospho-AKT levels were determined by immunoblot. (B) siRNA mediated reduction of IGFBP-1 protein expression. (C) After transfection with IGFBP-1 siRNAs or non-targeting control (NT), MCF-7 cells were treated with 1μM 4-OHT for 24 hours followed by 50 ng/mL IGF-1 stimulation for 15 minutes followed by the immunoblot analysis of p-IGF-1R (Y1135/1136), p-AKT (S473) and p-ERK1/2. (D) Extracellular IGFBP-1 protein concentration determined by ELISA. *, p<0.05 compared to vehicle, and #, p<0.05 compared to IGFBP-1 blocking Ab-treated. The results are representative of three independent experiments, and the error bars are SEM.