Epithelial-specific inhibition of Notch signaling in DNMAML model. (A) Scheme of DMAML-mediated inhibition of Notch signaling. The Notch intracellular domain (NICD; blue) forms a complex with suppressor of hairless and lag-1 (CSL; purple lined), Mastermind-like1 (MAML; pink), and co-activators (yellow lined), to activate transcription of Notch target genes. The DNMAML-GFP fusion protein blocks formation of the activation complex, thus preventing transcription of the target genes. (B) Pancreata from 15 week-old wild type (WT), p48Cre;LSL-
KrasG12D (KC), and p48Cre;LSL-
KrasG12D mice (KC;DNMAML) were analyzed for the expression of common Notch target genes, Hes1 (green column), Hey1 (yellow column) and Hey2 (red column) by qRT-qPCR. The expression levels were normalized to Gapdh. Data represent mean ± SEM. (C) Quantification of pancreatic intraepithelial neoplasia (PanIN) of age-matched KC and KC;DNMAML mice (n = 3-5 mice/genotype). Color-coding: acini (dark purple), acinar-ductal metaplasia (ADM; green), PanIN1A (light blue), PanIN2B (blue), PanIN2 (red), PanIN3 (dark red). Data represent mean ± SEM. The statistical difference was determined by two-tailed Student t-test. *p < 0.05, ***p < 0.0001. (D) Genetic makeup of KC;DNMAML mice. (E) Analysis of 15-week old mice. H&E staining (20×); collagen deposition (Gomori Trichrome; 20×); mucin accumulation (Periodic Acid Staining; PAS; 20×); a PanIN-specific marker (Claudin18; 40×), and proliferation (Ki67; 40×). (F) Analysis of 26-week old mice.