NSE is upregulated under different cellular stress conditions. (A) NSE expression assessed by real-time qPCR in 5 GBM cell lines and 2 patient specimens cultured in SCM and in (B) serum-starvation medium. (C) NSE, MAP2 and class III β-tubulin expression in GBM cell lines cultured in hypoxia, assessed by real-time qPCR. (D) NSE expression in 5 GBM cell lines was assessed by Western blot after 3 weeks' incubation in 0.5% oxygen hypoxia chamber. GBM cells cultured in normoxia were used as controls. (E) Densitometric analysis of Western blots showing increased expression of NSE in all GBM cell lines in hypoxia. mRNA and protein expression was normalized using the GAPDH gene and protein, respectively. Error bars represent SEM. Experiments were performed three times. *P< 0.05. N, normoxia; H, hypoxia.