Figure 4.

Cell cycle redistribution of HPV-negative (FaDu) and HPV-positive (2A3) cells after cisplatin (CDDP) treatment combined with single-dose (IR 2 Gy) (a) or fractionated irradiation (IR 3 × 2 Gy) (b). In the single-dose regimen, cells were analyzed 24 h after irradiation, and fractionated regimen cells were analyzed 24 h after the last irradiation. Data were obtained from three independent experiments with 5,000 events measured in each sample (mean ± standard error). *p < 0.05 to other experimental groups in G₂/M phase; **p < 0.05 between tumor models; ***p < 0.05 between single and fractionated irradiation alone or combined with cisplatin in 2A3 cells in G₂/M phase; ^†<0.05 to other experimental groups in the S phase ^#p < 0.05 between cisplatin and irradiation groups in the single vs fractionated regimen in the corresponding tumor model.