Figure 1: Slug expression in EL-Kras^G12D mice attenuates acinar-ductal metaplasia (ADM).

(a) TRE-Slug mice were generated as detailed in the Materials and Methods and crossed with EL-tTA mice to generate Slug (EL-tTA⁺/TRE-Slug⁺) mice. The mRNA samples from pancreas of control wild-type mice and Slug mice were analyzed for human (h) Slug, and mouse (m) GAPDH by RT-PCR (top). Tissue lysates from wild-type and Slug mice were analyzed for Slug and α-tubulin by Western blotting (bottom). Sections of mouse pancreas from wild-type and Slug mice at 3-months of age were H&E stained and observed at low and high magnification by phase microscopy. (b) The Slug mice were crossed with EL-Kras^G12D mice to generate mice expressing both Slug and Kras^G12D in the pancreas (Kras/Slug) or littermate control mice that express only Kras^G12D (Kras). The mRNA samples from pancreas of control Kras mice and Kras/Slug mice were analyzed for human (h) Slug and mouse (m) GAPDH by RT-PCR. Sections of mouse pancreas from Kras and Kras/Slug mice at 3-months of age were H&E stained and observed at low and high magnification by phase microscopy. The extent of ADM was quantified as described in the Materials and Methods. (c) The effect of Slug expression in Kras mice on amylase and CK19 expression was determined by immunofluorescence. The extent of CK19 expression was quantified as described in the Materials and Methods. (d) The effect of Slug on ERK1/2 phosphorylation (p-ERK1/2) was determined by immunohistochemistry. Relative number of p-ERK1/2(+) nuclei in wild-type, Kras and Kras/Slug mice were quantified. (e) The effect of Slug on proliferation (PCNA) was determined by immunofluorescence. Relative number of PCNA(+) nuclei in Kras and Kras/Slug mice were quantified. Scale bars correspond to 50 μm.