| First Author | Garcia-Carracedo D | Year | 2015 |
| Journal | PLoS One | Volume | 10 |
| Issue | 3 | Pages | e0120851 |
| PubMed ID | 25803032 | Mgi Jnum | J:229184 |
| Mgi Id | MGI:5751018 | Doi | 10.1371/journal.pone.0120851 |
| Citation | Garcia-Carracedo D, et al. (2015) Smad4 loss synergizes with TGFalpha overexpression in promoting pancreatic metaplasia, PanIN development, and fibrosis. PLoS One 10(3):e0120851 |
| abstractText | AIMS: While overexpression of TGFalpha has been reported in human pancreatic ductal adenocarcinoma (PDAC), mice with overexpressed TGFalpha develop premalignant pancreatic acinar-to-ductal metaplasia (ADM) but not PDAC. TGF-beta signaling pathway is pivotal to the development of PDAC and tissue fibrosis. Here we sought to investigate the interplay between TGFalpha and TGF-beta signaling in pancreatic tumorigenesis and fibrosis, namely via Smad4 inactivation. METHODS: The MT-TGFalpha mouse was crossed with a new Smad4 conditional knock-out mouse (Smad4flox/flox;p48-Cre or S4) to generate Smad4flox/flox;MT-TGFalpha;p48-Cre (STP). After TGFalpha overexpression was induced with zinc sulfate water for eight months, the pancreata of the STP, MT-TGFalpha, and S4 mice were examined for tumor development and fibrotic responses. PanIN lesions and number of ducts were counted, and proliferation was measured by Ki67 immunohistochemistry (IHC). Qualitative analysis of fibrosis was analyzed by Trichrome Masson and Sirius Red staining, while vimentin was used for quantification. Expression analyses of fibrosis, pancreatitis, or desmoplasia associated markers (alpha-SMA, Shh, COX-2, Muc6, Col1a1, and Ctgf) were performed by IHC and/or qRT-PCR. RESULTS: Our STP mice exhibited advanced ADM, increased fibrosis, increased numbers of PanIN lesions, overexpression of chronic pancreatitis-related marker Muc6, and elevated expression of desmoplasia-associated marker Col1A1, compared to the MT-TGFalpha mice. The inactivation of Smad4 in the exocrine compartment was responsible for both the enhanced PanIN formation and fibrosis in the pancreas. The phenotype of the STP mice represents a transient state from ADMs to PanINs, closely mimicking the interface area seen in human chronic pancreatitis associated with PDAC. CONCLUSION: We have documented a novel mouse model, the STP mice, which displayed histologic presentations reminiscent to those of human chronic pancreatitis with signs of early tumorigenesis. The STP mice could be a suitable animal model for interrogating the transition of chronic pancreatitis to pancreatic cancer. |
