G6PD suppression disrupts NADPH homeostasis and increases CRC cell susceptibility to oxidative stress. (a) Immunoblotting analysis of G6PD in DLD-1 and HCT116 cells transduced with two specific shRNA. (b) Growth curves of DLD-1 and HCT116 cells with knockdown of G6PD. Scramble (sc): the lentiviral vector with a scrambled sequence that does not target any mRNA. (c) NADPH/NADP+ and GSH/GSSG levels were measured in DLD-1 and HCT116 cells with knockdown of G6PD. (d, e) NADPH/NADP+ and ROS levels were measured in indicated cells treated with H2O2 (200 μm) for 24 h. (f) Representative of morphology of indicated cells treated with H2O2 (200 μm) for 48 h. Original magnification, × 200. (g) Cell apoptosis was measured by Annexin-V/PI assay in G6PD-knockdown and control cells treated with H2O2 (200 μm) for 48 h (red numbers indicate subpopulation of cells negative for Annexin-V/PI). Data are presented as the mean±s.d. (n=3). **P<0.01 for indicated comparison (Student unpaired t-test).