Tumor-derived IL-1β induces stromal glycolysis. (A) NFs and CAFs were treated with 20 ng/ml IL-1β alone or 20 ng/ml IL-1β + 20 mg/ml IL-1Ra for 48 h. CM were harvested at 6, 12, 24 and 48 h for residual glucose and lactate consumption analysis using glucose and lactate assay kits, respectively. (B) NFs and CAFs treated with 20 ng/ml IL-1β were collected for reverse transcription-quantitative polymerase chain reaction assays. Columns represent the mean ± standard deviation of three independent experiments. *P<0.05, **P<0.01 and ***P<0.001. (C) NFs and UM1 cells transfected with 10 nM nc or 10 nM si-IL1B were co-cultured for 48 h. NFs were then harvested for western blot analysis of GLUT1, HK2, LDHA and MCT4. Densitometry was used to determine target gene/GAPDH ratios. *P<0.05 vs. UM1-nc group. IL-1β, interleukin-1β; NFs, normal fibroblasts; CAFs, cancer-associated fibroblasts; IL-1Ra, interleukin-1 receptor antagonist; GLUT1, glucose transporter 1; HK2, hexokinase 2; LDHA, lactate dehydrogenase; MCT, mono-carboxylate transporter; siRNA, small interfering RNA; nc, negative control siRNA; si-IL1B, IL-1β siRNA.