Figure 2.

SMA-560, SMA-540 and U-251MG stem cell-enriched cultures are more radio-resistant than “differentiated” cultures. (A–E). Compared to standard culturing medium DMEM (closed circles; open bars), stem cell-inducing culture conditions with NSC medium (open circles; closed bars) increased clonogenic survival in (A) SMA-560, (B) SMA-540 and (E) (statistically non-significantly) U-251MG cells after irradiation. No statistically significant difference was observed in (C) GL-261 and (D) U-87MG cells (means ± SE of 3 experimental units with 4–6 observational units each). Numbers indicate error probabilities (p values) as calculated by Welch-corrected two-tailed t-test.