Figure 2
From: β1 integrin mediates an alternative survival pathway in breast cancer cells resistant to lapatinib
β1 blockade overcomes lapatinib resistance in BT474 cells in 3D culture. (A) Parental and LRes cells were plated on lrECM and treated ± lapatinib. (B) The β1 inhibitory antibody AIIB2--or IgG control--was applied to parental and LRes cells on Day 0 of plating on lrECM and allowed to grow for 12 days. (C) Parental and LRes cells were plated in lrECM with appropriate inhibitors, allowed to grow for five days, stained with Ki67 antigen or TUNEL labeling, and imaged. (D) 3D cultures of BT474 parental and LRes cells treated with AIIB2 or IgG were allowed to propagate for five days, then harvested for protein and immunoblotting. Densitometry measurements were normalized to total levels--except β1, which was normalized to β-actin--and are representative of three independent experiments. (E) The FAK inhibitor PF 573228 was applied to parental and LRes cells on Day 0 of plating on lrECM and cultures were allowed to grow for 12 days.