Fig. 5

a Representative Western blotting analysis of dose-dependent 5-FU-induced γ-H2AX, H2AX, PARP, cleaved PARP, p-Chk1^Ser317, Chk1, p-ATR.^Thr1989, ATR in HT29, B5, and F10 cells; ctrl: 24 h nontreated cells for control, GAPDH was used as loading control. Band intensities were quantified using ImageJ analysis software, and ratios were calculated against the GAPDH band intensity. For cleaved PARP, given ratios were calculated as cleaved PARP versus noncleaved PARP (ImageJ). b Western blotting analysis was performed by pretreating cells with the Chk1 inhibitor PF-00477736 (1.65 nM) for 1 h followed by 5-FU (15 µM) for 48 h; 48 h DMSO-treated cells were used as a control (-*), and GAPDH was used as a loading control. Band intensities were quantified using ImageJ analysis software, and ratios were calculated against the GAPDH band intensity. For cleaved PARP, given ratios were calculated as cleaved PARP versus noncleaved PARP (ImageJ)