Fig. 5

The effect of X-ray Irradiation on colony formation and invasion of lung cancer cells with hypermethylation or hypomethylation of the Dab2 gene promoter. a X-ray irradiation induced significant down-regulation of colony formation in irradiated LK cells compared with non-irradiated LK cells (a and b, 65.89% ± 15.83% VS 7% ± 4.2%, P < 0.05), however, the combination of X-ray irradiation and Dab2 knockdown significantly reversed this down-regulation compared with X-ray treatment alone (c, 54.11 ± 9.6%, P < 0.05). A similar effect was observed with combination of X-ray irradiation and Axin knockdown (d, 59.22 ± 14.73%, P < 0.05); However, X-ray irradiation alone was less effective in SPC cells compared with non-irradiated cells (e and f, 65.67 ± 9.54% VS 23.67 ± 8.51%, P < 0.05). Combination of X-ray irradiation and Dab2 siRNA (g, 54.44 ± 15.74%) or Axin siRNA (h, 53.78 ± 12.19%) also effectively reversed the down-regulation of clonal rate in SPC cells (P < 0.05); b The histogram of A; c Transwell cell invasion experiment demonstrated that the number of invasive LK cells decreased significantly after X-ray irradiation (b) compared to the non-irradiated group (a) (47 ± 10 VS 165 ± 30, P < 0.05). Combination of X-ray irradiation and Dab2 siRNA (c, 135 ± 40) or Axin siRNA (d, 139 ± 24) reversed the decreased invasive ability of LK cells (P < 0.05). The number of invasive SPC cells with irradiation (b, 83 ± 18) was less than that in non-irradiated SPC cells (a, 172 ± 40). X-ray irradiation induced decreased invasive ability of SPC cells was reversed by the transfection of Dab2 siRNA (c, 144 ± 45) and Axin siRNA (d, 140 ± 52); d The histogram of C. * P < 0.05