Fig. 1

Colorectal cancer cell lines show different intrinsic radio- and chemo-sensitivities. A CFU in response to radiations. For each cell line, 1000 cells were seeded at day 0 and irradiated with 2, 4, 6 or 8 Gy at D + 1. CFU from DLD-1 and HCT-116 or HT-29 were counted after an 8-days or 12-days incubation, respectively. B Radiation sensitivity of CRC cell lines. LD₅₀ values are indicated on the graph for the three cell lines (three parallel samples in three independent experiments). Student’s t-test was used to compare the results obtained for each radiation dose and p-values were indicated in the Table. C CFU in response to 5-FU. From each cell line, 1000 cells were seeded at day 0 and treated for 24 h with or without 5-FU (0.1, 1, 10 or 100 μM) at D + 1. CFU from DLD-1 and HCT-116 or HT-29 were counted after an 8-days or 12-days incubation, respectively. Colonies were counted using ImageJ [73]. D 5-FU sensitivity of CRC cell lines. IC₅₀ values are indicated on the graph for the three cell lines (three parallel samples in three independent experiments). Student’s t-test was used to compare the results obtained for each 5-FU dose and p-values were indicated in the Table. 5-FU: 5-fluorouracil; CFU: colony forming unit; CRC: colorectal cancer; Gy: Gray; LD₅₀: half maximal lethal dose; IC₅₀: half-maximal inhibitory concentration