title: Inactivation of Brca2 cooperates with Trp53(R172H) to induce invasive pancreatic ductal adenocarcinomas in mice: a mouse model of familial pancreatic cancer.
abstract: An inactivating germline mutation in BRCA2 is the most common known genetic basis for familial pancreatic cancer (FPC), accounting for 5-10% of inherited cases. A genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC) arising on the backdrop of Brca2 deficiency is likely to elucidate valuable diagnostic and therapeutic insights for FPC. Both Brca2 alleles were conditionally deleted during development within the pancreatic epithelium by generating Pdx1-Cre; Brca2(f/f) (CB) mice; in addition, triple transgenic Pdx1-Cre; Brca2(f/f); LSL-Trp53(R172H) (CBP) mice were generated, in order to determine the impact of p53 deregulation on Brca2-deficient carcinogenesis. Both CB and CBP mice developed non-invasive ductal precursor lesions (murine pancreatic intraepithelial neoplasia or mPanIN), although these were observed at an earlier time point (5 versus 8 months) and with higher prevalence in CBP mice. A minority of CB mice (15%) developed invasive and metastatic PDAC at a latency of 15 months or greater; in contrast, CBP mice of comparable age uniformly developed PDAC with variable histological features. Mortality in the absence of neoplasia in CB and CBP mice was associated with profound loss of pancreatic parenchyma, consistent with progressive elimination of Brca2-deficient cells. Widespread DNA damage, as evidenced by overexpression of the phosphorylated histone H(2)AX(Ser139), was observed in the non-neoplastic exocrine pancreas, as well as in the mPanIN and PDAC lesions of Brca2-deficient mice, independent of p53 status. Loss of Brca2 function predisposes the exocrine pancreas to profound DNA damage, and the frequency of invasive neoplasia is accentuated by the concomitant deregulation of p53.
authors: University of Bonn, Center of Integrated Oncology Cologne-Bonn, Bonn, Germany.
authors: Georg
authors: G
authors: Feldmann
authors: Collins
authors: C
authors: Karikari
authors: Marco
authors: M
authors: dal Molin
authors: Stephanie
authors: S
authors: Duringer
authors: Petra
authors: P
authors: Volkmann
authors: Detlef K
authors: DK
authors: Bartsch
authors: Savita
authors: S
authors: Bisht
authors: Jan-Bart
authors: JB
authors: Koorstra
authors: Peter
authors: P
authors: Brossart
authors: Anirban
authors: A
authors: Maitra
authors: Volker
authors: V
authors: Fendrich
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D000818:Animals; D024682:BRCA2 Protein / Q000235:genetics* / Q000378:metabolism; D002278:Carcinoma in Situ / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D004249:DNA Damage; D055785:Gene Knockdown Techniques; D056726:Genetic Association Studies; D053823:Hedgehog Proteins / Q000378:metabolism; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000556:secondary; D051379:Mice; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism; D013160:Splenic Neoplasms / Q000556:secondary; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: D024682:BRCA2 Protein; C106711:BRCA2 protein, mouse; D053823:Hedgehog Proteins; D016159:Tumor Suppressor Protein p53; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)