β-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation

Figure 1 Clonogenic survival of 5 gastric cancer cell lines after ionizing radiation. Cells were seeded into 6-well plates as indicated and exposed to corresponding doses of ionizing radiation after overnight recovery. Cells were incubated for 10 to 14 d to form colonies, then fixed with methyl alcohol and stained with 1% crystal violet solution. Colonies were counted and surviving fractions were calculated. Cell survival curves were fitted using Graphpad Prism 5.1 software according to the multi-target single hit model. Dots and bars: mean ± SD.