U87MG-EGFRvIII-MTS1 cells were more resistant to apoptosis inducers than U87MG-EGFRvIII cells. A,B, U87MG-EGFRvIII-MTS1 cells survived better than U87MG-EGFRvIII cells after treatments of apoptosis inducers. The cells were exposed to staurosporine (0-2 uM; Panel A) and anisomycin (0-200 ng/ml; Panel B) for 24 and 48 hrs and the survival rates determined using the Celltiter Blue Cell Survival Assay (Promega). C, U87MG-EGFRvIII-MTS1 cells are more resistant to anisomycin-induced apoptosis than U87MG-EGFRvIII cells. The extent of apoptosis was determined via the TUNEL assay, in which fragmented DNA is indicated by the yellow fluorescence signals, merged products of the red fluorescence (nuclei) and the green fluorescence (fragmented DNA).