Figure 7. Lapatinib and OSU-03012 interact to increase a toxic form of autophagy. (A) GBM12 cells were transfected with a plasmid to express GFP-LC3. Twenty four h later cells were treated with vehicle (DMSO) or with lapatinib (1 μM) and/or OSU-03012 (1 μM). Cells were examined 24h later under a fluorescent microscope to determine the number of GFP punctae per cell from 40 cells (n = 3, ± SEM). (B) GBM12 cells were transfected with a plasmid to express GFP-LC3 and with siRNA molecules to knock down ERBB1 and/or ERBB2. Cells were examined 24h later under a fluorescent microscope to determine the number of GFP punctae per cell from 40 cells (n = 3, ± SEM). (C) DAOY cells were transfected with a plasmid to express GFP-LC3 and with siRNA molecules to knock down ERBB1 and/or ERBB4. Cells were examined 24h later under a fluorescent microscope to determine the number of GFP punctae per cell from 40 cells (n = 3, ± SEM). (D) GBM12 cells were transfected with siRNA molecules to knock down Beclin1 or ATG5. Twenty four h later cells were treated with vehicle (DMSO) or with lapatinib (1 μM) and/or OSU-03012 (1 μM). Cells were isolated 24h later and viability determined by trypan blue exclusion assay (n = 3 ± SEM).