Fig. 2

Prolonged MTA pretreatment augments irradiation-induced senescence in A549 cells. a Representative images of cells acquired by phase contrast-based microscopy at day 6. b Quantification of senescent cells based on increased β-galactosidase activity (see Fig. 2a). Data represent means of two independent experiments and bars indicate means and standard deviations. *P < 0.05. c Forward and side scatter analysis was performed by flow cytometry at the indicated time points. Data shown are the mean values and standard deviations of three independent experiments