Fig. 4

Long-term TMZ treatment promotes diverse changes in proliferation, sensitivity to a glucose concentration reduction and colony formation efficiency in soft agar. a Cell proliferation in high-glucose medium. Cells were seeded at a density of 5 × 10⁴ (U251 and T98G derivatives) or 1 × 10⁴ (C6 derivatives) and grown in a high-glucose (4.5 g/L) DMEM with 10 % FBS. On the 7th day of seeding, cells viability was evaluated by trypan blue exclusion assay. b Cell proliferation in high- glucose medium versus low-glucose medium (1 g/L). c Representative photographs of plates with stained colonies (upper panel) and graphs comparing colony formation efficiency of the designated cell lines (lower panel). *P < 0.05; **P < 0.01; ***P < 0.001; NS non significant