(A and B) A549 CSLC cells cultured in the absence (Control) and presence of 10 μM gefitinib for 3 days were subjected to glucose uptake assay (A) and immunoblot analysis of GLUT1 expression (B). (C) A549 CSLC cells treated with or without 10 μM gefitinib in the presence or absence of 7.5 μM WZB-117 for 3 days were subjected to cell viability assay to determine the numbers of viable and dead cells (left panels) as well as the percentage of dead cells (right panels). (D and E) A549 CSLC cells were transfected with a non-targeting siRNA (siControl) or with either of the siRNAs against GLUT1 (siGLUT1#1 and siGLUT1#3) for 3 days. The cells were then subjected to immunoblot analysis of GLUT1 protein expression (D), or alternatively, treated with 10 μM gefitinib for another 3 days and subjected to cell viability assay to determine the numbers of viable and dead cells (left panels) as well as the percentage of dead cells (right panels) (E). (F) A549 CSLC cells cultured in the presence of the indicated concentrations of glucose were treated with or without 10 μM gefitinib for 3 days. Then, the cells were subjected to cell viability assay to determine the numbers of viable and dead cells (left panels) as well as the percentage of dead cells (right panels). Values in the graphs (A, C, E, and F) represent means and SD from three independent experiments. *P < 0.05 [note that the numbers of viable cells are compared in the left panels of C, E, and F].