Figure 1. Assessment of models currently used to study EGFR^vIII.

A. Glioblastoma samples were analyzed on the mRNA level for EGFR^vIII and EGFR^WT expression. B. Neurospheres obtained from glioblastoma resections positive for EGFR^vIII expression were treated with DMSO or erlotinib (10 μM). At least 3 neurospheres were analysed in each condition. C. Adherent cell line established from ARAD31 was cultured over several passages and EGFR^vIII and EGFR^WT mRNA levels were monitored. D. Stable cell lines, U87-MG and NCI-H460, were modified to express EGFR^vIII. Graph shows mRNA levels of EGFR^WT and EGFR^vIII. E. Western blot analysis of same cell lines as in D. Expected size: EGFR^WT - 175kDa, EGFR^vIII - 135kDa. Numbers to the left indicate molecular size. Arrows indicate not specific bands in NCI-H460 line. F. Ratio of an average mean fluorescence signal intensity per cell for total EGFR and EGFR^WT, an approximation of EGFR^vIII expression, is shown for NCI-H460 cell lines. (G and H) Populational growth of U87-MG cell lines in culturing medium supplemented with 10% FBS G. or without any supplements H. is shown. Legend to both graphs is on the right-hand side of H. Error bars indicate SEM. Statistical significance determined by ANOVA analysis with post-analysis Bonferroni's multiple comparisons test. ***, p < 0.05; ns, not significant.