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Sirtuin-1 regulates acinar to ductal metaplasia and supports cancer cell viability in pancreatic cancer
Abstracts / Pancreatology 13 (2013) S2–S98 3 4
Division of Radiology, University of Pisa, Pisa, Italy Division of Pathology, University of Pisa, Pisa, Italy
Introduction: 20% of the patients have a primary-resectable pancreatic ductal adenocarcinoma (PDAC), in 30-40% surgery is denied because of local tumor growth, in the absence of metastasis. These patients could be still be considered for resection, if responsive to neaodjuvant chemotherapy (NACT). Aims: We report the results of a phase-II-clinical-trial, coupling highdose-multi-drug-NACT with aggressive surgery. Patients & methods: All patients enrolled were selected by a multidisciplinary workgroup. Selection criteria: stage-III-locally-advancedPDAC (suspected arterial involvement), ECOG PS 0-1, age 18-75years. A modified-FOLFIRINOX regimen was used. Tumor response was evaluated according to RECIST. The opportunity to add a local treatment, either surgery or radiation-therapy, was evaluated after every CT follow-up. Results: Between 11/2010-11/2012, 26 patients (mean age 59years) were enrolled: 9/26 celiac axis involvement, 11/26 superior mesenteric artery, 6/26 celiac axis and superior mesenteric artery. 9 had a partial response (34%), 15 stable disease, 2 progressed. 14/26 underwent to surgery, 11/26 to resection with curative intent (47.8%): 2 pancreaticoduodenectomy, 9 total-splenopancreatectomy. Mean-operative-time was 618minutes. In-hospital-mortality was 9%, overall-postoperative-morbidity 62%, surgical morbidity 12%, medical morbidity 50%. Mean-hospital-stay was 26 days. 11/11 were R0. Resectedlymph-nodes-mean-number was 67, nodal-metastasis-mean-number 4. 12% of resected venous segments and 33% of resected arterial segments weren’t involved on histology. Overall-progression-free-survival was 17.6months, resected-patient-progression-free-survival 17.8, out-of-surgery-patient-progression-free-survival 10.3, median-overall-survival 24 Conclusion: The modified-FOLFIRINOX protocol in PDAC allows extended resection in a relevant percentage of stage-III-PDAC with results comparable to those in primary-resectable-patients. New data from further studies are needed before any final conclusion may be drawn.
PII-124 Abstract id: 343. Endoscopic ultrasound procedures on panceatic fluid Jozsef Hamvas 1, Laszlo Nehez 2. 1 2
Bajcsy-Zsilinszky Hospital, Budapest, Hungary Semmelweis University 1st. Surgical Clinic, Budapest, Hungary
Background: Pancreatic fluid often appear after acut pancreatitis, or associate with pancreatic neoplasms. Aim: Fluid samlpe taking by endoscopic ultrasound guided FNA for diagnosis pseodocyst malignancy. Patients & methods: In four years period 981 patient were examined by echoendoscop, 221 of them for pancreatic laesions. In 15 cases endoscopic pseudocysts drainage (EPD) were performed. Most of the cases went throught on ERCP to exclude major ductal leakage. In 14 caeses the pseuodocysts were drainaged with double pigtail endocystic plastic drain (7 and/or 10 F) throw the gastric wall, using endosonography. In one case self expanded metal stent (SEMS) was used to emptying the pseudocyst followed acut necrotising pancreatitis. Results: Our results revealed eligible cystemptying. Applying SEMS the EPD become “one step” procedure assured a large diameter of flow. In 30 cases the pancreatic fluid were only punctured.for diagnostic goals the cysts were not drainged, because of small diameter in 15 cases (2-3,5 cm) or bescause of septal structure of the pseudocyst. Mucinous cystadenoma were found in several cases mostly females (60-75 yrs), were operated on. In other cases pancreas neoplasm were the cytological diagnosis. Conclusion: The echoendoscope fine needle biopsy and aspiration is a well known method to distinguish malignant formations. In caeses of EPD using doppler echo effect ideal puncture site could be localising by excluding the intra cystic mass, and cystic wall vessels. Applying SEMS assured more simple modality of pseudocyst drainage.
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PII-125 Abstract id: 292. Comparison of chemoradiotherapy (CRT) and chemotherapy (CT) in patients with locally advanced pancreatic cancer (LAPC) controlled after 4 months of gemcitabine with or without erlotinib: Final results of the international phase III LAP 07 study Pascal Hammel 1, Florence Huguet 2, Jean-Luc van Laethem 3, David e 3, Jenny Goldstein 3, Bengt Glimelius 4, Ivan Borbath 3, Olivier Bouch e 3, Franck Bonnetain 3, Christophe Louvet 3. Shannon 3, Thierry Andr ^pital Beaujon Clichy, France Ho de Me decine, Universite Pierre-et-Marie-Curie, Paris, France Faculte 3 Erasme University Hospital, Brussels 4 Department of Radiology, Oncology and Radiation Science, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden 1 2
Background: In patients with LAPC controlled with CT, CRT could be superior to continuing CT (Huguet, JCO 2007). The role of erlotinib is unknown. Aim: To define: the roleof 1) CRT after disease control with gemcitabine and 2) role of erlotinibin LAPC. Patients & methods: LAPC PS 0-2 patients, 1st randomization: gemcitabine þ/- erlotinib 100 mg/d for 4 months (R1, stratification: center, PS). 2d randomization: patients with controlled LAPC had 2 additional months of CT (Arm 1) or CRT (Arm 2) 54 Gy and capecitabine 1600 mg/ m2/d (R2, stratification: center, initial arm). Patients receiving erlotinib at R1 had maintenance therapy. Quality control for RT: dummy runs /assessment of treated patients. Primary objective: overall survival (OS) in R2 patients. Secondary objectives: role of erlotinib on OS (R1), tolerance, predictive markers. 722 patients required to observe 392 deaths to show a median OS increase from 9 to 12 m (HR¼0.75) in the CRT arm with planned interim analyses. Kaplan-Meier, log rank and univariate Cox tests were used. Results: From 442 pts included for R1, 269 pts reached R2 (arm1:136; arm 2:133). Main baseline characteristics in arms 1/2: female 44%/56%, mean age 63/62, head tumor 65%/62%, PS 0 56%/48%. After a median follow-up of 36 m, 221 deaths had occurred allowing the planned interim analysis. OS in R2 pts was 16.5 m [15.5-18.5] and 15.3 m [13.9–17.3] in arms 1 and 2, respectively (HR¼1.03 [0.79-1.34], p¼0.83). IDMC has confirmed that the futility boundary for the hypothesis of CRT superiority was crossed. Conclusion: Administering CRT is not superior to continuing CT in patients with controlled LAPC after 4 months of CT. Symposium Presentations
Symposium on Pancreatic Regeneration and Repair S-1 Abstract id: 83. Sirtuin-1 regulates acinar to ductal metaplasia and supports cancer cell viability in pancreatic cancer ~ Ilse Rooman 1, Victor J. Sanchez-ArAÓvalo Lobo 2, Andreia V. Pinho 3, Luc 4 2 Bouwens , Francisco X. Real , Andrew V. Biankin 5, Elke Wauters 4. 1
The Garvan Institute of Medical Research, Vrije Universiteit Brussel, Australia 2 Spanish National Cancer Research Center (CNIO), Spain 3 The Garvan Institute of Medical Research, Spanish National Cancer Research Center (CNIO), Australia
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Abstracts / Pancreatology 13 (2013) S2–S98 4 5
Vrije Universiteit Brussel, Belgium The Garvan Institute of Medical Research, Australia
Introduction: The exocrine pancreas can undergo acinar to ductal metaplasia (ADM). ADM occurs in pancreatitis and can generate precursor lesions of pancreatic ductal adenocarcinoma (PDAC). Sirtuin 1 (Sirt1), a protein deacetylase, is an important regulator in cancer. Aims: We aim to study the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis. In addition, we analyse the expression of Sirt1’s key inhibitor Deleted in Breast Cancer 1 (Dbc1) and potential down stream targets. Materials & methods: We analysed pancreatic samples from mouse models and patient tumours by immunostainings, Western Blot and real time RT-PCR. We used mouse ADM models and established human PDAC cells to manipulate Sirt1’s expression and activity. Results: Sirt1 is co-expressed with Dbc1 in nuclei of normal acinar cells and loss of Sirt1 in normal pancreas has no apparent effects. In ADM however, Sirt1 but not Dbc1 undergoes a transient cytoplasmic shuttling, suggestive of a temporary decreased nuclear and increased cytoplasmic Sirt1 activity. Our observations indicate that this contributes to the ADM process. In addition to suppressive effects of a Sirtuin inhibitor on ADM, we also found that interference with Sirt1’s expression or application of an inhibitor in PDAC tumours results in loss of cell viability. In addition, we show that in PDAC, Dbc1 expression is differentially down regulated and the sensitivity of a panel of PDAC cell lines to a Sirt1 inhibitor correlates with Sirt1/Dbc1 expression. Conclusion: This is the first study to show that Sirt1 is a critical regulator and potential therapeutic target throughout pancreatic carcinogenesis.
S-2 Abstract id: 149. Combined pharmacological inhibition of Notch and JAK/STAT pathways effectively suppresses conversion from acinar-ductal metaplasia to pancreatic ductal adenocarcinoma and is superior to monotherapy
S-3 Abstract id: 290. Regeneration from acute pancreatitis requires transcriptional silencing of NFATc1 Moritz Dyck, Nai-Ming Chen, Elisabeth Glesel, Bettina Geisel, Kristina Reutlinger, Thomas M. Gress, Volker Ellenrieser. ^ University Marburg, Germany PhilippA’s Introduction: Tissue injury initiates a complex regenerative programme ensuring complete restoration of organ structure and function. Understanding the molecular key events in mediation and regeneration from pancreas injury is critical to develop novel therapeutic strategies. Recent evidence suggests important roles for developmental and inflammatory transcription factors in several steps of the regeneration process. Aims: To analyze whether and how the inflammatory transcription factor NFATc1 is involved in the course of acute pancreatitis. Materials & methods: Caerulein and L-Arginin were used to induce acute pancreatitis in different pancreas specific transgenic mice models with differential expression of NFATc1. Mice were sacrificed at different time points after induction of acute pancreatitis to isolate pancreata for further analysis. Gene expression in mice tissue and acinar cell explants were determined by using RT-PCR, immunoblotting, immunofluorescence and immunohistochemical stainings. Local histone modifications on the NFATc1 promoter were investigated by ChIP analysis. Results: Caerulein mediated acute pancreatitis initiates acinar to ductal metaplasia, which goes along with activation of NFATc1 in metaplastic areas of the pancreas. Regeneration of the pancreas requires inactivation of NFATc1 by H3K27 trimethylation mediated by the Polycomb protein EZH2. While pharmacological or genetic inactivation of NFATc1 in mice accelerates pancreas regeneration, sustained activation of NFATc1 overcomes transcriptional silencing and fully prevents restoration of the organ. Conclusion: Our results provide evidence, that transcriptional silencing of NFATc1 by EZH2 is an inevitable prerequisite for sufficient regeneration from acute pancreatitis.
Ruben Plentz 1, Vindhya Palagani 1, Przemyslaw Bozko 1, Mona El Khatib 1, Hanane Belahmer 1, Bence Sipos 2, Nisar Malek 1. 1 Department of Internal Medicine I, Medical University Hospital, Tuebingen, Germany 2 Institute of Pathology, University of Tuebingen, Germany
Introduction: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Recent studies have indicated that Notch and JAK2/STAT3 signaling pathways are both important for the initiation and progression of PDAC. Aims: The purpose of this study was to determine the outcome of targeting these two tumor signaling pathways simultaneously both in vitro and in vivo. Materials & methods: We assessed the combinational effects of the gsecretase inhibitor IX (GSI IX) and JAK2 inhibitor (AG-490) on growth and epithelial plasticity of human pancreatic cancer cell lines, and in a genetically engineered mouse model (Pdx1- Cre; LSL-KrasG12D; p53 lox/þ) of PDAC. Results: Dual treatment with GSI IX and AG-490 significantly impaired cell proliferation, migration, invasion, soft agar growth and apoptosis when compared to monotherapies. Notably, inhibition of Hes1 down regulated phosphorylation of STAT3 and reflects a synergistic effect. Most importantly, combinational treatment significantly attenuates tumor progression in vivo and suppresses conversion from acinar-ductal-metaplasia (ADM) to PDAC. Conclusion: Our results suggest that targeting Notch and JAK2/STAT3 signaling pathways simultaneously is superior to single inhibitions, supporting combined treatment by GSI X and AG-490 as a potential therapeutic approach for PDAC.
S-4 Abstract id: 231. Antidromic NFATc1 and p53 signaling at the edge of differentiation and stemness in pancreatic cancer €lker, Sophia Vogt, Bettina Geisel, Nai-ming Shiv Singh, Nadine Vo Chen, Elisabeth Glesel, Sandra Baumgart, Garima Singh, Irene Esposito, Thomas Gress, Volker Ellenrieder. Signaling and Transcription Laboratory, Internal Medicine, Dept. of Gastroenterology, Philipps University of Marburg, Germany, Germany Introduction: The current concept suggests a direct link between EMT and stemness induction in pancreatic cancer, thereby coupling cell motility and de-differentiation with self-renewal capacities and drug resistance. Both key features of cellular plasticity are controlled by distinct intracellular signaling and transcription pathways. We have shown that NFATc1 activation promotes PDAC and metastasis through its ability to integrate extrinsic stimuli into coordinated gene regulation. Aims: To assess whether NFATc1 controls transcription of EMT genes and stemness in PDAC, particularly upon p53 inactivation. Patients & methods: We generated mouse strains with combined pancreas-specific expression of NFATc1, p53R172H and KrasG12D. These mice showed a highly aggressive tumor growth. Mouse primary tumour cells were used to identify NFATc1 targets by gene expression profiling and pathway analyses (ChIP seq, miRNA analyses and GSEA). NFATc1 mediated
Division of Radiology, University of Pisa, Pisa, Italy Division of Pathology, University of Pisa, Pisa, Italy
Introduction: 20% of the patients have a primary-resectable pancreatic ductal adenocarcinoma (PDAC), in 30-40% surgery is denied because of local tumor growth, in the absence of metastasis. These patients could be still be considered for resection, if responsive to neaodjuvant chemotherapy (NACT). Aims: We report the results of a phase-II-clinical-trial, coupling highdose-multi-drug-NACT with aggressive surgery. Patients & methods: All patients enrolled were selected by a multidisciplinary workgroup. Selection criteria: stage-III-locally-advancedPDAC (suspected arterial involvement), ECOG PS 0-1, age 18-75years. A modified-FOLFIRINOX regimen was used. Tumor response was evaluated according to RECIST. The opportunity to add a local treatment, either surgery or radiation-therapy, was evaluated after every CT follow-up. Results: Between 11/2010-11/2012, 26 patients (mean age 59years) were enrolled: 9/26 celiac axis involvement, 11/26 superior mesenteric artery, 6/26 celiac axis and superior mesenteric artery. 9 had a partial response (34%), 15 stable disease, 2 progressed. 14/26 underwent to surgery, 11/26 to resection with curative intent (47.8%): 2 pancreaticoduodenectomy, 9 total-splenopancreatectomy. Mean-operative-time was 618minutes. In-hospital-mortality was 9%, overall-postoperative-morbidity 62%, surgical morbidity 12%, medical morbidity 50%. Mean-hospital-stay was 26 days. 11/11 were R0. Resectedlymph-nodes-mean-number was 67, nodal-metastasis-mean-number 4. 12% of resected venous segments and 33% of resected arterial segments weren’t involved on histology. Overall-progression-free-survival was 17.6months, resected-patient-progression-free-survival 17.8, out-of-surgery-patient-progression-free-survival 10.3, median-overall-survival 24 Conclusion: The modified-FOLFIRINOX protocol in PDAC allows extended resection in a relevant percentage of stage-III-PDAC with results comparable to those in primary-resectable-patients. New data from further studies are needed before any final conclusion may be drawn.
PII-124 Abstract id: 343. Endoscopic ultrasound procedures on panceatic fluid Jozsef Hamvas 1, Laszlo Nehez 2. 1 2
Bajcsy-Zsilinszky Hospital, Budapest, Hungary Semmelweis University 1st. Surgical Clinic, Budapest, Hungary
Background: Pancreatic fluid often appear after acut pancreatitis, or associate with pancreatic neoplasms. Aim: Fluid samlpe taking by endoscopic ultrasound guided FNA for diagnosis pseodocyst malignancy. Patients & methods: In four years period 981 patient were examined by echoendoscop, 221 of them for pancreatic laesions. In 15 cases endoscopic pseudocysts drainage (EPD) were performed. Most of the cases went throught on ERCP to exclude major ductal leakage. In 14 caeses the pseuodocysts were drainaged with double pigtail endocystic plastic drain (7 and/or 10 F) throw the gastric wall, using endosonography. In one case self expanded metal stent (SEMS) was used to emptying the pseudocyst followed acut necrotising pancreatitis. Results: Our results revealed eligible cystemptying. Applying SEMS the EPD become “one step” procedure assured a large diameter of flow. In 30 cases the pancreatic fluid were only punctured.for diagnostic goals the cysts were not drainged, because of small diameter in 15 cases (2-3,5 cm) or bescause of septal structure of the pseudocyst. Mucinous cystadenoma were found in several cases mostly females (60-75 yrs), were operated on. In other cases pancreas neoplasm were the cytological diagnosis. Conclusion: The echoendoscope fine needle biopsy and aspiration is a well known method to distinguish malignant formations. In caeses of EPD using doppler echo effect ideal puncture site could be localising by excluding the intra cystic mass, and cystic wall vessels. Applying SEMS assured more simple modality of pseudocyst drainage.
S89
PII-125 Abstract id: 292. Comparison of chemoradiotherapy (CRT) and chemotherapy (CT) in patients with locally advanced pancreatic cancer (LAPC) controlled after 4 months of gemcitabine with or without erlotinib: Final results of the international phase III LAP 07 study Pascal Hammel 1, Florence Huguet 2, Jean-Luc van Laethem 3, David e 3, Jenny Goldstein 3, Bengt Glimelius 4, Ivan Borbath 3, Olivier Bouch e 3, Franck Bonnetain 3, Christophe Louvet 3. Shannon 3, Thierry Andr ^pital Beaujon Clichy, France Ho de Me decine, Universite Pierre-et-Marie-Curie, Paris, France Faculte 3 Erasme University Hospital, Brussels 4 Department of Radiology, Oncology and Radiation Science, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden 1 2
Background: In patients with LAPC controlled with CT, CRT could be superior to continuing CT (Huguet, JCO 2007). The role of erlotinib is unknown. Aim: To define: the roleof 1) CRT after disease control with gemcitabine and 2) role of erlotinibin LAPC. Patients & methods: LAPC PS 0-2 patients, 1st randomization: gemcitabine þ/- erlotinib 100 mg/d for 4 months (R1, stratification: center, PS). 2d randomization: patients with controlled LAPC had 2 additional months of CT (Arm 1) or CRT (Arm 2) 54 Gy and capecitabine 1600 mg/ m2/d (R2, stratification: center, initial arm). Patients receiving erlotinib at R1 had maintenance therapy. Quality control for RT: dummy runs /assessment of treated patients. Primary objective: overall survival (OS) in R2 patients. Secondary objectives: role of erlotinib on OS (R1), tolerance, predictive markers. 722 patients required to observe 392 deaths to show a median OS increase from 9 to 12 m (HR¼0.75) in the CRT arm with planned interim analyses. Kaplan-Meier, log rank and univariate Cox tests were used. Results: From 442 pts included for R1, 269 pts reached R2 (arm1:136; arm 2:133). Main baseline characteristics in arms 1/2: female 44%/56%, mean age 63/62, head tumor 65%/62%, PS 0 56%/48%. After a median follow-up of 36 m, 221 deaths had occurred allowing the planned interim analysis. OS in R2 pts was 16.5 m [15.5-18.5] and 15.3 m [13.9–17.3] in arms 1 and 2, respectively (HR¼1.03 [0.79-1.34], p¼0.83). IDMC has confirmed that the futility boundary for the hypothesis of CRT superiority was crossed. Conclusion: Administering CRT is not superior to continuing CT in patients with controlled LAPC after 4 months of CT. Symposium Presentations
Symposium on Pancreatic Regeneration and Repair S-1 Abstract id: 83. Sirtuin-1 regulates acinar to ductal metaplasia and supports cancer cell viability in pancreatic cancer ~ Ilse Rooman 1, Victor J. Sanchez-ArAÓvalo Lobo 2, Andreia V. Pinho 3, Luc 4 2 Bouwens , Francisco X. Real , Andrew V. Biankin 5, Elke Wauters 4. 1
The Garvan Institute of Medical Research, Vrije Universiteit Brussel, Australia 2 Spanish National Cancer Research Center (CNIO), Spain 3 The Garvan Institute of Medical Research, Spanish National Cancer Research Center (CNIO), Australia
S90
Abstracts / Pancreatology 13 (2013) S2–S98 4 5
Vrije Universiteit Brussel, Belgium The Garvan Institute of Medical Research, Australia
Introduction: The exocrine pancreas can undergo acinar to ductal metaplasia (ADM). ADM occurs in pancreatitis and can generate precursor lesions of pancreatic ductal adenocarcinoma (PDAC). Sirtuin 1 (Sirt1), a protein deacetylase, is an important regulator in cancer. Aims: We aim to study the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis. In addition, we analyse the expression of Sirt1’s key inhibitor Deleted in Breast Cancer 1 (Dbc1) and potential down stream targets. Materials & methods: We analysed pancreatic samples from mouse models and patient tumours by immunostainings, Western Blot and real time RT-PCR. We used mouse ADM models and established human PDAC cells to manipulate Sirt1’s expression and activity. Results: Sirt1 is co-expressed with Dbc1 in nuclei of normal acinar cells and loss of Sirt1 in normal pancreas has no apparent effects. In ADM however, Sirt1 but not Dbc1 undergoes a transient cytoplasmic shuttling, suggestive of a temporary decreased nuclear and increased cytoplasmic Sirt1 activity. Our observations indicate that this contributes to the ADM process. In addition to suppressive effects of a Sirtuin inhibitor on ADM, we also found that interference with Sirt1’s expression or application of an inhibitor in PDAC tumours results in loss of cell viability. In addition, we show that in PDAC, Dbc1 expression is differentially down regulated and the sensitivity of a panel of PDAC cell lines to a Sirt1 inhibitor correlates with Sirt1/Dbc1 expression. Conclusion: This is the first study to show that Sirt1 is a critical regulator and potential therapeutic target throughout pancreatic carcinogenesis.
S-2 Abstract id: 149. Combined pharmacological inhibition of Notch and JAK/STAT pathways effectively suppresses conversion from acinar-ductal metaplasia to pancreatic ductal adenocarcinoma and is superior to monotherapy
S-3 Abstract id: 290. Regeneration from acute pancreatitis requires transcriptional silencing of NFATc1 Moritz Dyck, Nai-Ming Chen, Elisabeth Glesel, Bettina Geisel, Kristina Reutlinger, Thomas M. Gress, Volker Ellenrieser. ^ University Marburg, Germany PhilippA’s Introduction: Tissue injury initiates a complex regenerative programme ensuring complete restoration of organ structure and function. Understanding the molecular key events in mediation and regeneration from pancreas injury is critical to develop novel therapeutic strategies. Recent evidence suggests important roles for developmental and inflammatory transcription factors in several steps of the regeneration process. Aims: To analyze whether and how the inflammatory transcription factor NFATc1 is involved in the course of acute pancreatitis. Materials & methods: Caerulein and L-Arginin were used to induce acute pancreatitis in different pancreas specific transgenic mice models with differential expression of NFATc1. Mice were sacrificed at different time points after induction of acute pancreatitis to isolate pancreata for further analysis. Gene expression in mice tissue and acinar cell explants were determined by using RT-PCR, immunoblotting, immunofluorescence and immunohistochemical stainings. Local histone modifications on the NFATc1 promoter were investigated by ChIP analysis. Results: Caerulein mediated acute pancreatitis initiates acinar to ductal metaplasia, which goes along with activation of NFATc1 in metaplastic areas of the pancreas. Regeneration of the pancreas requires inactivation of NFATc1 by H3K27 trimethylation mediated by the Polycomb protein EZH2. While pharmacological or genetic inactivation of NFATc1 in mice accelerates pancreas regeneration, sustained activation of NFATc1 overcomes transcriptional silencing and fully prevents restoration of the organ. Conclusion: Our results provide evidence, that transcriptional silencing of NFATc1 by EZH2 is an inevitable prerequisite for sufficient regeneration from acute pancreatitis.
Ruben Plentz 1, Vindhya Palagani 1, Przemyslaw Bozko 1, Mona El Khatib 1, Hanane Belahmer 1, Bence Sipos 2, Nisar Malek 1. 1 Department of Internal Medicine I, Medical University Hospital, Tuebingen, Germany 2 Institute of Pathology, University of Tuebingen, Germany
Introduction: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Recent studies have indicated that Notch and JAK2/STAT3 signaling pathways are both important for the initiation and progression of PDAC. Aims: The purpose of this study was to determine the outcome of targeting these two tumor signaling pathways simultaneously both in vitro and in vivo. Materials & methods: We assessed the combinational effects of the gsecretase inhibitor IX (GSI IX) and JAK2 inhibitor (AG-490) on growth and epithelial plasticity of human pancreatic cancer cell lines, and in a genetically engineered mouse model (Pdx1- Cre; LSL-KrasG12D; p53 lox/þ) of PDAC. Results: Dual treatment with GSI IX and AG-490 significantly impaired cell proliferation, migration, invasion, soft agar growth and apoptosis when compared to monotherapies. Notably, inhibition of Hes1 down regulated phosphorylation of STAT3 and reflects a synergistic effect. Most importantly, combinational treatment significantly attenuates tumor progression in vivo and suppresses conversion from acinar-ductal-metaplasia (ADM) to PDAC. Conclusion: Our results suggest that targeting Notch and JAK2/STAT3 signaling pathways simultaneously is superior to single inhibitions, supporting combined treatment by GSI X and AG-490 as a potential therapeutic approach for PDAC.
S-4 Abstract id: 231. Antidromic NFATc1 and p53 signaling at the edge of differentiation and stemness in pancreatic cancer €lker, Sophia Vogt, Bettina Geisel, Nai-ming Shiv Singh, Nadine Vo Chen, Elisabeth Glesel, Sandra Baumgart, Garima Singh, Irene Esposito, Thomas Gress, Volker Ellenrieder. Signaling and Transcription Laboratory, Internal Medicine, Dept. of Gastroenterology, Philipps University of Marburg, Germany, Germany Introduction: The current concept suggests a direct link between EMT and stemness induction in pancreatic cancer, thereby coupling cell motility and de-differentiation with self-renewal capacities and drug resistance. Both key features of cellular plasticity are controlled by distinct intracellular signaling and transcription pathways. We have shown that NFATc1 activation promotes PDAC and metastasis through its ability to integrate extrinsic stimuli into coordinated gene regulation. Aims: To assess whether NFATc1 controls transcription of EMT genes and stemness in PDAC, particularly upon p53 inactivation. Patients & methods: We generated mouse strains with combined pancreas-specific expression of NFATc1, p53R172H and KrasG12D. These mice showed a highly aggressive tumor growth. Mouse primary tumour cells were used to identify NFATc1 targets by gene expression profiling and pathway analyses (ChIP seq, miRNA analyses and GSEA). NFATc1 mediated