FIGURE 8.

FN:STAT3 signaling is required for 3D organotypic outgrowth of MDA-MB-231 cells. A, representative photomicrographs of cells propagated in three-dimensional organotypic cultures for 11 days under control (basement membrane extract (BME)) or FN-supplemented conditions in the absence or presence of EGFR (1 μm Erlotinib or 1 μm AG1478), JAK2 (1 μm WP1066), or STAT3 (1 μm Stattic or 1 μm STAT3i VII) inhibitors. Bars, ×100 magnification. B, MDA-MB-231 cells were propagated in three-dimensional organotypic cultures with or without supplemental FN and longitudinal outgrowth was quantified by bioluminescence at the indicated time points. C, MDA-MB-231 cells were propagated under FN-supplemented three-dimensional conditions as in panel B in the absence (IgM) or presence of β1 integrin neutralizing antibody (α-β1-Int). Three-dimensional cellular outgrowth was quantified using a bioluminescence 11 days post-plating. D, three-dimensional cellular outgrowth of the MDA-MB-231 cells cultured in the absence (NS) or presence of EGFR (1 μm Erlotinib or 1 μm AG1478), JAK2 (1 μm WP1066), or STAT3 (1 μm STAT3 Inhibitor VII or 1 μm Stattic) inhibitors. Data in panels B–D are the mean ± S.E. of two independent experiments completed in triplicate.