logy

O-35.

Abstract withdrawn

Abstracts / Pancreato

O-36.

Pain sensation in pancreatic diseases is not uniform - the different fa-cets of pancreatic pain

Jan DHaese a, Mark Hartel a, Ihsan Ekin Demir a, Ulf Hinz b, FrankBergmann c, Markus W. Büchler d, Helmut Friess a, Güralp O. Ceyhan a

a Department of Surgery, Klinikum Rechts der Isar, TechnischeUniversit€at München, Munich, Germany, GermanybUnit for Documentation and Statistics, Department of GeneralSurgery, University of Heidelberg, Heidelberg, Germany, Germanyc Institute of Pathology, University of Heidelberg, Heidelberg, Germany,GermanydDepartment of General Surgery, University of Heidelberg, Heidelberg,Germany, Germany

Background: Abdominal pain is a major clinical feature in chronicpancreatitis and pancreatic cancer. Little is known about pain sensations inother pancreatic tumors.

Aims: With this study, we aimed to systematically characterize specificpain patterns in the most frequent pancreatic diseases.

Patients & methods: Pain in patients with chronic pancreatitis(n¼314), pancreatic cancer (n¼469), and other pancreatic tumors (n¼249)including mucinous (n¼20) and serous cystadenoma (n¼31), invasive(n¼37) and non-invasive intraductal papillary mucinous neoplasia (IPMN;n¼48), low stage (n¼18) and high stage neuroendocrine neoplasia (n¼44),and ampullary cancer (n¼51) was registered and correlated with clin-icopathological data.

Results: 49.1% of pancreatic cancer patients revealed no pain, whereasin chronic pancreatitis only 18.3% were pain free. In contrary, moderate/severe pain was registered in 15.1% in pancreatic cancer patients that wasincreased in chronic pancreatitis with up to 34.2%. Serous cystadenomawasasymptomatic in most cases (58.1%), whereas 78.9% of all mucinous cys-tadenoma patients suffered pain. In neuroendocrine neoplasia painwas nota key clinical symptom since 64% of low stage neuroendocrine neoplasiaand 59% of high stage neuroendocrine neoplasia patients were pain free.Cancer localization in the pancreatic body and patients with malignantpancreatic neoplasms were associated with more severe pain. Tumorgrading and stage did not show any impact on pain. Only in pancreaticcancer, pain was directly associated with impaired survival.

Conclusion: Pancreatic pain depicts different patterns of abdominalpain sensation according to the respective pancreatic disorder and does notallow a unification of the term pancreatic pain.

O-37.

K-Ras regulation of G2 Cyclins via a Cyclin D-independent mechanism

Robert Ferguson a, Wafa AbuAlainin a, Asmaa Salman a, JohnNeoptolemos a, Eithne Costello a, William Greenhalf a

a Department of Molecular and Clinical Cancer Medicine, University ofLiverpool, UK., United Kingdom

Background: K-Ras mutations occur in 75-90% of pancreatic adeno-carcinomas. Since K-Ras acts upstream of a complex network of pathways itis difficult to know what effects these mutations have, particularly giventhe variety of genetic backgrounds of cancer cells. Depletion of K-Rasprotein from pancreatic cell lines causes a decrease in cell division that isusually assumed to result from non-activation of the MAP-Kinase pathway.

Aims: The aim of this work was to determine whether K-Ras mutationregulates cell division exclusively via Cyclin D.

Materials & methods: K-Ras and Cyclin D were depleted in pancreaticcancer cell lines using siRNAwith or without the inhibition of MAP-Kinase,PI-3 kinase or the proteosome. FACS andWestern analysis was undertaken.Ras activity was measured by pull down with Raf.

Results: K-Ras depletion caused a reduction of APC targets: G2cyclins, geminin and survivin. This could be due to a shift from G2 toG1. However, FACS analysis showed no significant reduction in G2 andBRDU label accumulated in G2 ephase cells. Depleting Cyclin D alsoresulted in decreased cyclins A, B and geminin but it didn’t affectsurvivin levels. Inhibiting the Proteasome did not stabilise Cyclin D afterK-Ras knock down but did stabilise G2 cyclins. Neither independentinhibition of MAP-kinase or PI3 kinase mimicked K-Ras knockdown. K-Ras knockdown eliminated K-Ras activity but not N-Ras activity whichremained high in the cells.

Conclusion: Mutant K-Ras stabilises G2 cyclins by a specific pathwaythat is not exclusively dependent on MAP kinase/Cyclin D.

14 (2014) S1eS129 S13

O-38.

Acinar-specific TGF-b signaling regulates acinar cell regeneration

Kamile Grabliauskaite, Sabrina Sonda, Enrica Saponara, Theresia RedingGraf, Rolf Graf

University Hospital Zurich, Switzerland

Background: TGF-b signalling is implicated in regeneration and fib-rosis of pancreatic cells. However, the function of TGF-b signalling isstrongly context-dependent and an acinar cell specific role of this mole-cule in modulating regeneration has not been completely investigatedbefore.

Aims: In this study we aimed to determine the contribution of TGF-bsignaling to acinar cell regeneration during pancreatitis by using micedeficient in TGF-b receptor II (TGFbRIIfl/fl) in acinar cells.

Materials & methods: Pancreatitis was induced in control and PTF1a-CreTg; TGFbRIIfl/fl mice by multiple injections of cerulein. The expression ofproliferation markers, cell cycle regulators, and the severity of tissueinflammation and fibrosis were analysed by immunohistochemistry,western blotting and qRT-PCR.

Results: Our analyses revealed formation of extended acinar-to-ductalmetaplasia (ADM) in TGFbRIIfl/fl mice together with increased expression ofAKT, a protein involved in ADM development. Smad3 activation, which iscapable to inhibit AKT, was not observed in TGF b RIIfl/fl compared to controlgroup animals. Furthermore, the lack of TGF-b receptor II resulted in anincreased number of proliferating acinar cells. Concurrently, the expressionof the cell cycle inhibitor p16INK4a, a TGF-b signalling target, was selec-tively reduced. In addition, we observed higher stellate cells activation andstronger fibrosis accompanied by a robust inflammation in TGFbRIIfl/fl micecompared to control animals.

Conclusion: Our data revealed that TGF-b signalling prevents excessiveADM formation and inhibits activation of acinar cell cycle. Additionally, lossof TGF-b signalling in acinar cells potentiates fibrogenic processes duringpancreatitis, suggesting the existence of a regulatory feedback betweenacinar and stellate cells.