Figure 3. Lapatinib-resistant BT474 cells overexpress MCL-1 and BCL-XL and have reduced expression of toxic BH3 domain proteins. (A) BT474 cells (WT, wild type; AR, anoikis-resistant) in triplicate were treated with vehicle (VEH, DMSO), dacomitinib (dacom., 100 nM), obatoclax (GX, 50 nM), or the drug combination. Cells were isolated 12 h later and viability determined by trypan blue (± SEM, n = 3) ^#P < 0.05 less than others values in (dacom. + GX) cells; **P < 0.05 greater than VEH cells. (B) BT474 cells (WT, wild type; AR, anoikis-resistant) in triplicate were treated with vehicle (VEH, DMSO), afatinib (AFA, 100 nM), obatoclax (GX, 50 nM) or the drug combination. Cells were isolated 12 h later and viability determined by trypan blue (± SEM, n = 3) ^#P < 0.05 less than others values in (AFA. + GX) cells; **P < 0.05 greater than VEH cells. (C) BT474 cells (WT, wild type; AR, anoikis-resistant) were plated in a Millipore Millicell. The migration of cells was determined after 12 h (± SEM, n = 3) *P < 0.05 greater than corresponding value in WT cells.