Fig. 3

Characterisation of PRDX1 and PRDX2-knockdown ZR-75-1 breast cancer cell line. a Western blotting shows downregulation of PRDX1 or PRDX2 proteins in ZR-75-1 cell line derivatives compared to parental and shNTC controls. β-actin was used as a loading control. b Representative images for the colony formation in ZR-75-1 cells (left panel) and a quantitative analysis of colony formation assay (right panel) shows a significant decrease of colony number in cells carrying shPRDX1, in contrast to controls and PRDX2-knockdown cells. Data shown are cumulative results from three independent experiments. **p < 0.01. c Concentration-dependent cytotoxicity of GOx in ZR-75-1 cells. Cells were treated with GOx (0.25; 0.5; 1 mU/ml) for 24 h. Control cells were cultured without any reagent. At the end of treatment, the crystal violet staining (or MTT test, see Suppl. Fig. S3D) was performed and reported as percent growth relative to control. d Relative fluorescence intensity (log₂ values) of PY1 probe after reaction with H₂O₂ produced by GOx in shPRDX1 and shPRDX2 ZR-75-1 cells compared to controls was assessed as described in Fig. 2e