Cell Cycle and Apoptosis Analysis

Cells were seeded in 6-well plates, incubated for 24 h, and treated with PBS, 5-azaC (1 μmol/l), IR (6 Gy), or 5-azaC + IR as described above. Cell cycle progression and apoptosis were analyzed with the Cell Cycle and Apoptosis Kit (Keygentec, China) using a CytomicsTM FC500 flow cytometer and CXP analysis software (Beckman Coulter, USA) following the manufacturer’s instructions. Cell cycle analysis was performed using CXP analysis software; apoptotic cells were considered to include cells stained Annexin V (+)/propidium iodide (PI) (−) (lower right quadrant, early apoptosis) and late cells stained Annexin V (+)/PI (+) (upper right quadrant, late apoptosis) [22] (link).For each sample, at least 10,000 cells were analyzed.