Figure 4.

Effect of co-culture with senescence-like A549 cells on the survival of non- and irradiated A549 cells. (A) A schematic of the co-culture experiment is shown. A549 cells irradiated with 10 Gy were cultured for 7 days to induce senescence-like cells (S cells). Non-irradiated and X-ray irradiated A549 cells were seeded in dishes with or without S cells for the colony-forming assay. (B) The relative colony number of non-irradiated A549 cells in the presence and absence of S cells is shown. (C) The surviving fraction of A549 cells with and without S cells is shown. S cells (+) and S cells (−) indicate with and without S cells, respectively. Data are presented as the mean ± SD of independent experiments. * p < 0.05.