Figure 1.

Cell viability and clonogenic survival of HNSCC cells in response to radiation and cisplatin exposure. Parental FaDu, SCC25 and CAL27 and appropriate radiation-resistant IRR cells were seeded in six-well plates, treated with ionising radiation at a single dose of 2 Gy (A) or cisplatin at a clinically relevant single dose of 10 μM (B) and then incubated for 72 h. Cell viability and number of cells was evaluated using the Beckman Coulter Vi-CELL AS cell viability analyser. Data are given as mean and s.d. obtained from at least three independent experiments. (C and D) Clonogenic cell survival assay. Colonies were counted on the fourteenth day following radiation (C) or cell exposure to cisplatin (D), and surviving fractions were plotted as a function of dose on a log-linear scale. Error bars indicate s.d. from mean of duplicate measurements from at least four independent experiments. **P<0.01; ***P<0.001.