Hypoxia pretreatment increased the sphere and colony formation capability of cells.(A) Figure 3A shows representative spheres of the cells cultivated under normoxia. (B) Results from three independent experiments show significantly more spheres in the hypoxia pre-treated groups than the control groups for both cell lines (P < 0.0001). (C) Colony formation assay shows more colonies in the hypoxia pre-treated cells. (D) Results from three independent experiments show significantly more colonies in the hypoxia pre-treated groups than those in the normoxia controls (P < 0.0001).
Liang et al. BMC Cancer 2012 12:201 doi:10.1186/1471-2407-12-201