Rac1 and Stathmin but Not EB1 Are Required for Invasion of Breast Cancer Cells in Response to IGF-I
Figure 2
Expression and activation of IGF-IR and PI3K in MDA-MB-231 and MCF7 cells. (a) After stimulation with IGF-I for 0, 0.5, or 6 h, cells were lysed and processed for immunoblotting with anti-IGF-IR antibody. Values are given as band intensity relative to that in unstimulated control MDA-MB-231 cells. (b) After stimulation with IGF-I, cells were immunostained with antibody to phospho-IGF-IR (Tyr1135/1135). Scale Bars 20 μm. (c) After stimulation with IGF-I, cells were lysed and processed for immunoblotting with anti-PI3K (p85) antibody. Values are given as band intensity relative to that in unstimulated control MDA-MB-231 cells. (d) Cells after stimulation with IGF-I were lysed and immunoprecipitated with anti-PI3K (p85) antibody. PI3K activity was assayed for the immunoprecipitates as described in Materials and Methods. The mean (SD) values of triplicate assays are given as activity relative to that in unstimulated control MDA-MB-231 cells.
