Circulating free tumor DNA (cftDNA) as a novel biomarker for the early detection of cancer in familial pancreatic cancer families

Circulating free tumor DNA (cftDNA) as a novel biomarker for the early detection of cancer in familial pancreatic cancer families

S24 Abstracts / Pancreatology 16 (2016) S1eS130 1 University of Szeged, First Department of Medicine, Hungary University of Szeged, Department of Ph...

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S24

Abstracts / Pancreatology 16 (2016) S1eS130 1

University of Szeged, First Department of Medicine, Hungary University of Szeged, Department of Pharmacology and Pharmacotherapy, Hungary 3 University of Szeged, First Department of Medicine, Department of Pathophysiology, Hungary 4 cs, Institute for Translational Medicine & Department University of Pe of Translational Medicine/1st Department of Medicine, MTA-SZTE Lendület Translational Gastroenterology Research Group, University of Szeged, Hungary 2

Introduction: Cystic fibrosis (CF) is a lethal genetic disease affecting several organs, including the pancreas. Although animal models are available to study the CF related tissue damage they have clear limitations. Recently a cystic fibrosis transmembrane regulator (CFTR) knock out ferret model was generated. This model would be the first available one to study pharmacological prevention of the disease development. Aims: We aimed to characterize the fluid and bicarbonate secretion of wild type (WT) ferret pancreatic ducts. Materials & methods: Expression of CFTR was detected by immunohistochemistry. Intra/interlobular pancreatic ducts were isolated from the WT ferret pancreas. Resting pH, buffer capacity and Cl-/HCO3 exchange activity were evaluated by microfluorometry. Fluid secretion was examined by video microscopy. Results: CFTR was expressed on the luminal membrane of ferret pancreatic ducts. The resting intracellular pH of pancreatic epithelial cells is lower (7.17±0,08) in ferrets compared to mice (7.31) or to guinea pigs (7.36). Concerning the bicarbonate influx mechanisms, functionally active sodium/hydrogen exchanger and sodium/bicarbonate cotransporter were detected. Anion exchanger activity measured by NH4Cl-technique, Cl removal and inhibitory stop methods indicated that ferret pancreatic ducts secrete similar amount of bicarbonate as mice and guinea pigs. Video microscopy revealed a significant increase in fluid secretion to HCO-3 and to 5mM forskolin stimulation. Conclusion: Ferret pancreatic ductal epithelial cells express the major epithelial ion transporters. Our results indicate that ferret could be a suitable model organism to study the CF related pancreatic damage. Moreover this model open up the possibilities to test pharmacological interventions in the disease development.

Abstract ID: 1561. Circulating free tumor DNA (cftDNA) as a novel biomarker for the early detection of cancer in familial pancreatic cancer families Julie Earl 1, Carmen Guill en-Ponce 1, Reyes Ferreiro 1, Vanessa Pachon 1, Maria Teresa Salazar Lopez 1, Celia Calcedo 1, Jose Carlos Martinez-Avila 2, zquezMirari Marquez 3, Mercedes Rodríguez-Garrote 1, Enrique Va ~ oz-Beltran 5, Francisco Real 6, Nuria Malats 3, Sequeiros 4, Maria Mun Alfredo Carrato 1  n y Cajal University Hospital, Medical Oncology Department, Ramo IRYCIS, Madrid, Spain 2 Epidemiology, Bioinformatics and Biostatistics Health Research Institute, Hospital 12 de Avda de Cordoba s/n, Edificio de activi, Spain 3 Genetic & Molecular Epidemiology Group, Spanish National Cancer Research Centre, Madrid, Spain 4  n y Cajal University Hospital, Madrid, Digestive Department, Ramo Spain 5 n y Cajal University Hospital, Madrid, Radiology Department, Ramo Spain 6 Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre, Madrid, Spain 1

Introduction: Familial Pancreatic Cancer (FPC) is an autosomal dominant rare syndrome defined as families with two or more first-degree relatives with pancreatic ductal adenocarcinoma (PDAC) that do not fulfill the criteria of any other inherited tumor syndrome. The incidence of PDAC is higher in these families. The key to improving prognosis in PDAC may lie in early detection of the disease although there are few reliable markers to check for microscopic disease.

Aims: validate novel minimally invasive tumor markers for early detection of Pancreatic Cancer (PC) at a potentially curative stage in FPC. Patients & methods: Primary tumor DNA and circulating free DNA in plasma from familial and sporadic PDAC cases were tested for a tumor related KRAS mutation (G12D, G12V and G12R) by ddPCR. Results: Primary tissue was available for 6 familial cases and 4 (66%) tested positive for a KRAS mutation. KRAS mutant cfDNA was detected in 3/ 12 of familial PDAC and 5/19 sporadic cases. However, as we only tested the most common KRAS mutations, this is likely to be an under estimate. The presence of mutant KRAS in plasma correlated strongly with Overall Survival (OS), 60 days (95% CI:19-317) for mutation positive versus 772 days for mutation negative (95% CI:416-1127). Conclusion: Pancreatic familial cancer families represent the only high-risk group defined for screening. KRAS mutation detection is a potentially early biomarker in the familial pancreatic cancer setting as these were found in 66% of primary tumors and 25% of plasma samples.

Abstract ID: 1564, Oral-12. Pancreas epithelial-specific knockout of Smad7 in cerulein-induced pancreatic fibrosis Rainer Heuchel 1, Xuan Li 1, Yasmin Yu 1, Salvatore Nania 1, Caroline €hr 1 Verbeke 2, Matthias Lo 1

Centre for Digestive Diseases, Karolinska University Hospital and Division of Surgery, CLINTEC, Karolinska Institutet, Stockholm, Sweden 2 Department of Pathology, Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway Introduction: Chronic pancreatitis is the most common disease of exocrine pancreas, characterized by progressive inflammation, acinar atrophy and fibrosis. TGF-b is the most potent fibrogenic cytokine responsible for macrophage attraction, stellate cell activation and collagen expression in damaged tissue. Smad7 is induced by the TGF-b superfamily members as an intracellular inhibitory protein that antagonizes TGF-b signaling. We have recently demonstrated that the general knockout of Smad7 results in significantly increased fibrotic response in murine experimental pancreatitis. Aims: To understand the mechanisms of pancreatic fibrosis in more detail. Materials & methods: We conditionally inactivated Smad7 using a CreeLoxP system under the control of the pancreatic and duodenal homeobox 1 promoter (Pdx1), specific for the pancreatic epithelium, and evaluated the pathological changes in a mouse model of cerulein-induced chronic pancreatitis. Results: We first analyzed the accumulation of extracellular matrix proteins by Sirius Red staining. To our surprise, the fibrotic index between wildtype and mutant mice was comparable. In addition, there was no difference in deposition of collagen-I and fibronectin expression as assessed by immunohistochemistry. We observed a slightly decreased infiltration of inflammatory cells, albeit without statistical significance. Finally, also the number of myofibroblasts, indicated by vimentin staining, in the pancreata of Smad7 mutant and wild type mice was comparable. Conclusion: Taken together, we concluded that Smad7 in the pancreatic epithelium does not have a significant influence on the development of cerulein-induced chronic pancreatitis. Thus the crosstalk among epithelial, stromal, and immune compartments need to be further investigated in order to better understand the role Smad7/TGF- b in pancreatitis.

Abstract ID: 1565. VX-809 restores the expression defect of cystic fibrosis transmembrane conductance regulator caused by alcohol in Capan-1 cells csy 1, Petra Pallagi 1, Vikto zsef Mal ria Venglovecz 2, Jo eth 1, Tamara Mada n Rakonczay, Jr. 3, P eter Hegyi 4 Zolta 1

First Dept. of Medicine, University of Szeged, Hungary