Fig. 4

AK4 shifts metabolism toward aerobic glycolysis and increases oxidative stress. a Global GSEA statistics of differentially expressed genes in AK4-overexpressing CL1-0 cells compared with vector-expressing CL1-0 cells. b GSEA plots and KEGG metabolic pathways of Glycolysis_Gluconeogenesis and Glutathione_Metabolism pathways between CL1-0 AK4 cells and CL1-0 Vec cells. c Relative ATP levels, glucose consumption, and lactate production upon AK4 overexpression in CL1-0 cells. **P ≤ 0.01 d Relative ADP/ATP ratio upon AK4 overexpression in CL1-0 cells under Nx or Hx. *P ≤ 0.05 e Intracellular ROS level of vector-expressing CL1-0 cells and AK4-expressing CL1-0 cells; the ROS level was normalized to vector-expressing CL1-0 cells. **P ≤ 0.01. f WB analysis of HIF-1α in CL1-0 vector- and AK4-expressing cells treated with or without 10 mM NAC under Nx or Hx. g Invasion assay of CL1-0 vector- or AK4-expressing cells treated with 10 mM NAC under Nx or Hx. h Intracellular ROS level of shNS-expressing CL1-5 cells and shAK4-expressing CL1-5 cells. The ROS level was normalized to shNS-expressing CL1-5 cells. **P ≤ 0.01. i Time course analysis of HIF-1α and AK4 protein expression in CL1-5 cells treated with 10 mM NAC for the indicated time. j Invasion assay of CL1-5 cells treated with or without 10 mM NAC. The results are presented as the mean ± SD of at least three separate experiments. Two-tailed, unpaired Student’s t tests were used for all pairwise comparisons. *P ≤ 0.05; **P ≤ 0.01