Genetic deletion of IKKβ in IMCs inhibits colitis-associated tumorigenesis. (A) Representative immunoblot analysis of IKKβ protein expression in thioglycolate-elicited peritoneal macrophages (TEPMs), colonic IMCs and IECs, from Ikkβ^F/F (F/F) and Ikkβ^IMCko (IMCko) mice. E-cadherin, α-SMA and F4/80 were used as cell-specific markers. β-Actin was used as loading control. (B) Quantification of IKKβ expression in three independently established colonic IMC cultures after normalization with β-actin (**, P < 0.01, using Student’s t test). (C) Representative quantification by FACS analysis of mTomato⁺ and GFP⁺ cells in mesenchymal cell cultures from the colon (n = 4 individual cultures). (D) Representative confocal image of mTomato⁺ and GFP⁺ cells in mesenchymal cell cultures from the colon (n = 4 individual cultures). Bar, 50 µm. (E) Schematic diagram of the AOM/DSS model of CAC. A single AOM injection (10 mg/kg) is followed by three cycles of 2% DSS administration in the drinking water. (F) Body weight loss of Ikkβ^F/F and Ikkβ^IMCko treated with AOM/DSS. (G) Macroscopically visible tumors were counted, and then (H) tumor size, (I) colon length, and (J) colitis score were measured in Ikkβ^IMCko and Ikkβ^F/F littermate controls at day 60 of the CAC model. (K) Representative images of H&E sections from Ikkβ^F/F and Ikkβ^IMCko mice on day 60. Bar, 200 µm. All data are presented as mean ± SE from one of three individual experiments performed (n ≥ 6 mice per group; *, P < 0.05; **, P < 0.01; ns, nonsignificant, using Student’s t test).