Fig. 1

Radiation-resistant MCF7/C6 cells are more invasive cancer cells. a Increased radioresistance measured by clonogenic survivals of MCF7 and MCF7/C6 cells. b NHEJ efficiency measured by in vivo EJ assay. Cells were co-transfected with linearized EJ5-GFP plasmid and control pDsRed, and were then treated with 2 Gy of IR. Re-circulated EJ5-GFP was counted by flow cytometry analysis 72 h after transfection. c Representative images for transwell invasion assay and wound-healing assays (top: invasion assay; middle: migration assay; bottom: wound healing assay). d Relative quantitation of cellular invasiveness, migration and wound healing ability in MCF7/C6 cells compared with the wild type MCF7 cells. e Western blots of E-Cadeherin in MCF7 and MCF7/C6 cells. β-actin was included for equivalent protein loading. Data represent the average from at least three independent experiments. *Indicates statistical significance (p < 0.05)