Fig. 2

Catalase gene silencing and catalase activity inhibition sensitized Resox cells to ascorbate/menadione treatment. a Efficiency of catalase gene silencing (siRNA) in breast cancer cell lines was evaluated by western blot. b, c MCF-7 cells were transfected 48 h with control (siRNA CTL) or catalase siRNA (siRNA CAT). Then, cells were incubated with various concentrations of H₂O₂ (mM) or with indicated menadione at μM concentrations associated with ascorbate in a ratio Asc/Men 1:100. Cytotoxicity was evaluated by MTT. d, e Resox cells were transfected 48 h with control (siRNA CTL) or catalase (siRNA CAT) siRNA. Then, cells were incubated as reported in B-C. f, g MCF-7 cells were incubated for 24 h with PBS or 5 mM ATA. Then, cells were incubated as reported in (b–c). h–i Resox cells were incubated for 24 h with PBS or 5 mM ATA. Then, cells were incubated as reported in (b, c). Data are mean ± s.e.m. Groups were compared using two-way ANOVA test for (b–i). *p value < 0.05; **p value < 0.01