Figure 11

ErPC and ErPC3 decrease the number of clonogenic T98G cells and increase radiation-induced eradication of clonogenic T98G cells. Effects of ErPC and ErPC3 alone or in combination with ionizing radiation on clonogenic cell survival was determined by standard colony formation assays. 24 h after plating T98G cells were treated with increasing concentrations of (A) ErPC or (C) ErPC3 alone or (B, D) in combination with ionizing radiation with 0, 2.5, 5 and 10 Gy. In the latter case, ErPC or ErPC3 were added 10 min after irradiation. Subsequently, cells were incubated under standard culturing conditions up to 4 weeks. For determination of colony formation cells were fixed in 3.7% paraformaldehyde and 70% ethanol and stained with 0.05% Coomassie blue. Colonies composed of at least 50 cells were counted. Data represent means ± s.d., n = 3