Figure 3From: Fibroblast-secreted hepatocyte growth factor mediates epidermal growth factor receptor tyrosine kinase inhibitor resistance in triple-negative breast cancers through paracrine activation of MetHepatocyte growth factor stimulates Met phosphorylation and enhances clonogenic survival in the presence of gefitinib. (A) SUM102 and SUM149 cells were cultured with condition media from RMF-HGF fibroblasts for 1 hour in the presence or absence of 0.5 μM gefitinib (gef). Lysates were prepared and analyzed for Met phosphorylation using immunoblotting. Met and β-actin expression levels were used as controls. CM, pro-hepatocyte growth factor (pro-HGF) conditioned media; UT, untreated. (B) SUM102 and SUM149 cells were treated with conditioned media from RMF-HGF fibroblasts in the presence or absence of the indicated concentration of gefitinib or erlotinib for 7 days, adding fresh drug and conditioned media (CM) every other day. Cells were trypsinized, replated, and grown under normal growth conditions for 7 days. Colonies were stained using crystal violet and counted using a cell counter. Each experiment was performed in triplicate at least three times. Student's t test was used to determine survival differences between gefitinib-treated cells in the presence or absence of conditioned media.Back to article page