Fig. 6: Effects of E2F1 and TYMS silencing on 5-FU treatment of CCA cells.

Either E2F1 or TYMS expression in HuCCA cell was silenced using siRNA (siE2F1 or siTS). Non-silencing siRNA (NS-siRNA) was used as a control. After 24 h, HuCCA cells were reseeded and grown overnight. a After treatment with 100 μM 5-FU for 24 h, cells were harvested and the expression of FOXM1, E2F1 and TYMS was determined by western blot analysis using β-tubulin as loading control. b Effects of E2F1 and TYMS silencing on 5-FU toxicity was also investigated using a clonogenic assay. Representative clonogenic assay images show the effect on 5-FU treatment of silencing of either E2F1 or TYMS. Data are presented as mean ± SEM (n = 3) and were analysed by two-way ANOVA. Single and triple asterisks (* and ****) indicates significant difference at p < 0.05 and p < 0.001, respectively, from the non-targeting siRNA-treated control cells; ‘ns’ indicates no significant difference