Figure 2.

DCQ reduces the clonogenic survival of HCT116 cells more so under hypoxia than normoxia. (A) Clonogenic survival of DCQ-treated cells exposed to normoxic or hypoxic conditions. At 50% confluency, cells were treated for 12 hrs with different DCQ concentrations in normoxia or hypoxia, after which they were replated at low densities and colonies (more than 50 cells) were stained and counted after 10-14 days in culture. Surviving fractions were calculated as mentioned in "Methods". (*) indicates p < 0.05 (one way ANOVA). (B) Effect of DCQ on HIF-1α protein expression. Cells were plated in 100 mm dishes and treated for 6 hrs with DCQ while in normoxia or hypoxia. Whole cell lysates were immunoblotted for HIF-1α. GAPDH was used to ensure equal loading. Relative densitometry values are presented at the bottom of the blots. All ratios were normalized to GAPDH and calculated relative to the control cells cultured under oxia. The experiment was repeated three times each in triplicates.