Figure 4. NF-κB activation was essential for cerulein to induce chronic inflammation and precancerous lesions in acinar-Ras mice.

After 2 series of cerulein treatments (week 4), pancreata of acinar-Ras mice showed increased NF-κB subunit p65 nucleus translocation (A, arrows; original magnification, ×400) as compared with controls (B, ×400). Triple transgenic mice (acinar-Ras-IKK^fl/fl), which express mutant K-Ras^G12D with IKK2 deletion, displayed a significant reduction of fibrosis and inflammation (C, original magnification, ×100) and Ras activity (D) after 2 series of cerulein treatments. The degree of stellate cell activation and retention of pancreas parenchyma in acinar-Ras-IKK^fl/fl mice was measured by quantification of α-SMA for stellate cells (E) and amylase for acinar cells (F) (*P < 0.05 compared with acinar-Ras mice; n = 4 animals). GAPDH was probed for relative protein loading control (note: GAPDH in D and F was from the same gel).