Fig. 4

IL-17 signals to transformed epithelial cells to suppress CXCL9 family chemokine production. a Cdx2-Cre⁺/Apc^F/+ mice were crossed to Il17ra-flox mice to generate a conditional ablation of Il17ra gene in colorectal epithelial cells and tumor cells. These mice carry Cdx2-Cre⁺/Apc^F/+/Il17ra^F/− genotypes and are labeled as “Il17ra^F/−”. Cdx2-Cre⁺/Apc^F/+/Il17ra^F/+ mice (labeled as Il17ra^F/+) were used as controls. Both groups of mice were sacrificed at 5 months of age. Colorectal tumors and adjacent normal colon tissues were harvested for q-RT-PCR analysis. n = 6. b Tumor cells were isolated from colorectal tumors of Cdx2-Cre-ERT2⁺/Apc^F/F mice 4 weeks after tamoxifen injection. Cells were then cultured a 3-D system to allow their development into primary tumor spheres. Tumor spheres were subsequently treated with vehicle control (PBS with 0.1% BSA) or 100 ng/ml recombinant human IL-17A, C, or F for 24 h, followed by q-RT-PCR analysis (n = 3, and data represent one of three consistent tests). Data represent means ± S.E.M. *p < 0.05 in Students’ t test