Knockdown of G6PD enhances oxaliplatin efficacy in vivo. (a) G6PD knockdown or control DLD-1 cells (2 × 106) were subcutaneously injected into the nude mice. The mice were treated with oxaliplatin when the tumor volume reached 100 mm3 in the control group, and images of tumors derived from indicated group are shown. (b, c) The tumor growth curves and tumor weights of indicated group mice were measured and recorded. (d) Paraffin-embedded tumor sections derived from DLD-1 cells bearing mice were stained with H&E or cleaved caspase 3 antibodies (scale bar: 100 μm); apoptotic cells were visualized and quantified by TUNEL staining (green) and counterstained with DAPI (blue) (scale bar: 10 μm). (e) Quantification of cleaved caspase 3 levels and apoptotic index (TUNEL staining) in CRC tumors was shown. Data are presented as the mean±s.d. (n=5). **P<0.01 for indicated comparison (Student unpaired t-test).