Fig. 5: Combined treatment with ABT-263 and ionizing radiation reduces short-term and long-term-term survival in response to acute hypoxia in hypoxia-selected cells.
From: Bcl-2/Bcl-xL inhibitor ABT-263 overcomes hypoxia-driven radioresistence and improves radiotherapy
A, B HCT116 cells and non-selected and hypoxia-selected NCI-H460 cells were treated as indicated with ABT-263, ionizing radiation (IR), or both in normoxia (Nx, 20% O2) or in severe hypoxia (Hx, <0.2% O2). After 48 h, attached cells were fixed and stained with crystal violet solution. Spectrophotometrical measurement of released dye after cell lysis was used to calculate the amount of viable cells by normalizing the values to untreated controls or irradiation-only treated cells. A Short-term survival after treatment with ABT-263 and B after additional irradiation. C Upper surviving curves: Following treatment with ABT-263 and irradiation under normoxic conditions, the cells were incubated in normoxia for 12 days. Lower surviving curves: Following treatment with ABT-263 and irradiation under hypoxic conditions, the cells were kept in severe hypoxia for 48 h before transfer to and further incubation in normoxia for 10 days. Formed colonies (bottom, representative images) were counted and surviving fractions were calculated. Data show mean values of at least three independent experiments ±SD. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001. A, B *, **, *** above bars: comparing treatment with ABT-263 to non-treated respective controls (0 µM ABT-263) at respective conditions. C *, **, ***: comparing effects after treatment with ABT-263 to these after treatment with solvent (0 µM ABT-263) at respective conditions.
