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Thyroid hormone T3 is required for acinar cell proliferation following cerulein induced acute pancreatitis
Abstracts / Pancreatology 16 (2016) S1eS130
Introduction: Pancreatic Ductal Adenocarcinoma (PDAC) constitutes one of the most aggressive malignancies with a dismal prognosis, mainly due to therapeutic resistance mediated by cellular plasticity installed by epigenetic alterations. The histone methyltransferase EZH2, a member of the Polycomb-Repressor-Complex 2, is upregulated in many tumor entities and seems to play a significant role in evasion of apoptosis, senescence and DNA damage repair, thus fostering cancer development and progression. Aims: To characterize the therapeutic potential of EZH2 inhibition in PDAC treatment. Materials & methods: To examine oncogenic EZH2-functions, genetic and pharmacological (EPZ-6438) approaches were used to interfere with EZH2 expression in human and murine PDAC cells. BrdU-, Sphere-assays and FACS-analysis were performed to assess cell proliferation, stemness characteristics and cell cycle progression, respectively. Gene expression of key factors of apoptosis and senescence were measured using qRT-PCR and immunoblotting. p53 metabolism was influenced by cycloheximide-, nutlin- and MG132-treatments. The impact of EZH2 on PDAC cell chemosensitivity was determined by MTT-assays. Immunoprecipitation was performed to investigate MDM2/p53/EZH2 complexes. Results: EZH2 inhibition results in growth inhibition mediated by restitution of apoptosis, senescence and cell cycle arrest. Importantly, the anti-tumorigenic functions of EZH2-inhibition are restricted to PDAC cells with p53 wildtype expression. Mechanistically, EZH2 overexpression blocks tumor-failsafe mechanisms by posttranslational physical stabilization of the MDM2-dependent p53-degradation complex in PDAC cells. Conclusion: EZH2 inhibition might represent a beneficial strategy to overcome disruption of cellular failsafe mechanisms in PDAC subtypes with p53 wildtype expression, thus emphasizing the significance of therapeutic stratification approaches to tackle PDAC.
Abstract ID: 1424, Oral-47. Thyroid hormone T3 is required for acinar cell proliferation following cerulein induced acute pancreatitis Ermanno Malagola 1, Kathryn Schlesinger 1, Enrica Saponara 1, Kamile Grabliauskaite 1, Theresia Reding 1, Arnold von Eckardstein 2, Maren Dietrich 3, Rolf Graf 1, Sabrina Sonda 1 1 Department of Visceral and Transplantation Surgery, University Hospital, Zurich, Switzerland 2 Institut für Klinische Chemie, University Hospital, Zurich, Switzerland 3 €hrung, Klinik für Endokrinologie, Diabetologie und Klinische Erna University Hospital, Zurich, Switzerland
Introduction: Thyroid hormones (TH) play an important role during development as well as regeneration of several tissues. 3,5,30 -triiodo-Lthyronine (T3) is considered to be the active form of thyroid hormones. Aims: In the present study we asked whether acinar cell proliferation following acute pancreatitis is dependent on TH action. Materials & methods: Wild type C57BL/6 mice received serial injections of cerulein to induce pancreatitis; TH levels were altered in vivo by either T3 supplementation or pharmacological hypothyroidism. A panel of selective inhibitors were injected in vivo in combination with T3 to investigate the molecular mechanism beyond T3 action. Levels of cell proliferation, inflammation and dedifferentiation were investigated through immunohistochemistry as well as gene expression analysis. Serum THs' levels were quantified by biochemical analyses. Results: Gene expression analysis revealed a pancreas specific regulation of TH pathway following acute pancreatitis. Hypothyroid mice showed significant impairment in acinar cell proliferation following cerulein treatment and T3 supplementation was able to rescue this phenotype by inducing acinar cell proliferation without increasing damage or inflammation. Gene expression as well as immune assays revealed upregulation of AKT, histone deacetylases (HDACs) and b-catenin following T3 supplementation; use of selective inhibitors for AKT and HDAC reduced T3 induction of proliferation unveiling their involvement in the pathway.
S11
Conclusion: Endogenous TH pathway is activated following acute pancreatitis and drives acinar cell proliferation. Moreover we found that T3 driven acinar cell proliferation is dependent on AKT and HDAC action. All together our data define an important role of TH in pancreas homeostasis and regeneration.
Abstract ID: 1430. A comparison of transverse and midline incisions for pancreaticoduodenectomy Pooja Prasad, James Hodson, Chris Coldham, Ravi Marudanayagam, John R. Isaac, Robert P. Sutcliffe, Paolo Muiesan, Darius F. Mirza, Keith J. Roberts University Hospitals Birmingham, NHS Foundation Trust, United Kingdom Introduction: Various technical aspects of pancreaticoduodenectomy (PD) contribute towards the significant morbidity and mortality associated with this procedure. One aspect of surgical technique is the type of incision utilised. PD may be performed via a transverse subcostal or a midline incision. Aims: We sought to evaluate the clinical outcomes amongst a consecutive cohort of patients undergoing PD at our unit, stratified by incision type. Patients & methods: Consecutive patients undergoing PD were identified from a prospectively maintained database from January 2012 to May 2015. Patient variables, intraoperative data, analgesic usage, pain scores and post-operative complications (including incisional hernia) were obtained from electronic hospital records, and compared between the incision types. Results: Amongst 231 patients undergoing PD, 160 and 71 patients underwent PD via transverse and midline incisions respectively. There was no significant difference between the incision types for any patient or perioperative variables considered, with the exception of the nature of pancreaticoenteric anastomosis. The incision type was not found to have a significant effect on the reporting of severe pain postoperatively (p¼0.642), with an odds ratio for midline, relative to transverse, of 1.10 (95% CI: 0.73 e 1.66). No post-operative physiological parameter was related to the incision type. There was no significant difference in the development of incisional hernias (p¼0.247), with rates at one year of 14.5% and 16.8% in the midline and transverse incision groups, respectively. Conclusion: This study found no evidence to suggest that the type of incision used to perform PD has any significant impact on the development of post-operative complications.
Abstract ID: 1434, Oral-48. The hypothalamic neuropeptide, orexin, prevents chronic pancreatitis in cerulein mice model Anne Couvelard 1, Vinciane Rebours 2, Christopher Prochasson 3, ephanie Dayot 3, Thierry Voisin 3, Maxime Bergere 3, Nassima Messal 3, St Alain Couvineau 3 1
Pathological Unit, Bichat Hospital, Paris, France Pancreatology Unit, Beaujon Hospital, Clichy, France 3 Paris 7, Paris, France INSERM UMR1149, Universite 2
Introduction: Chronic pancreatitis leads to the permanent deterioration of the structure and function of the pancreas characterized by inflammation, fibrosis and exocrine/endocrine insufficiency. Orexins (orexin-A and orexin-B) are hypothalamic peptides involved in the sleep/ wake control which interact with two GPCR sub-types, OX1R and OX2R. We have recently observed that OX1R is highly expressed in acinar and ductal cells in all human pancreatitis tested. Moreover, we have demonstrated the anti-inflammatory role of orexin-A in ulcerative colitis.
Introduction: Pancreatic Ductal Adenocarcinoma (PDAC) constitutes one of the most aggressive malignancies with a dismal prognosis, mainly due to therapeutic resistance mediated by cellular plasticity installed by epigenetic alterations. The histone methyltransferase EZH2, a member of the Polycomb-Repressor-Complex 2, is upregulated in many tumor entities and seems to play a significant role in evasion of apoptosis, senescence and DNA damage repair, thus fostering cancer development and progression. Aims: To characterize the therapeutic potential of EZH2 inhibition in PDAC treatment. Materials & methods: To examine oncogenic EZH2-functions, genetic and pharmacological (EPZ-6438) approaches were used to interfere with EZH2 expression in human and murine PDAC cells. BrdU-, Sphere-assays and FACS-analysis were performed to assess cell proliferation, stemness characteristics and cell cycle progression, respectively. Gene expression of key factors of apoptosis and senescence were measured using qRT-PCR and immunoblotting. p53 metabolism was influenced by cycloheximide-, nutlin- and MG132-treatments. The impact of EZH2 on PDAC cell chemosensitivity was determined by MTT-assays. Immunoprecipitation was performed to investigate MDM2/p53/EZH2 complexes. Results: EZH2 inhibition results in growth inhibition mediated by restitution of apoptosis, senescence and cell cycle arrest. Importantly, the anti-tumorigenic functions of EZH2-inhibition are restricted to PDAC cells with p53 wildtype expression. Mechanistically, EZH2 overexpression blocks tumor-failsafe mechanisms by posttranslational physical stabilization of the MDM2-dependent p53-degradation complex in PDAC cells. Conclusion: EZH2 inhibition might represent a beneficial strategy to overcome disruption of cellular failsafe mechanisms in PDAC subtypes with p53 wildtype expression, thus emphasizing the significance of therapeutic stratification approaches to tackle PDAC.
Abstract ID: 1424, Oral-47. Thyroid hormone T3 is required for acinar cell proliferation following cerulein induced acute pancreatitis Ermanno Malagola 1, Kathryn Schlesinger 1, Enrica Saponara 1, Kamile Grabliauskaite 1, Theresia Reding 1, Arnold von Eckardstein 2, Maren Dietrich 3, Rolf Graf 1, Sabrina Sonda 1 1 Department of Visceral and Transplantation Surgery, University Hospital, Zurich, Switzerland 2 Institut für Klinische Chemie, University Hospital, Zurich, Switzerland 3 €hrung, Klinik für Endokrinologie, Diabetologie und Klinische Erna University Hospital, Zurich, Switzerland
Introduction: Thyroid hormones (TH) play an important role during development as well as regeneration of several tissues. 3,5,30 -triiodo-Lthyronine (T3) is considered to be the active form of thyroid hormones. Aims: In the present study we asked whether acinar cell proliferation following acute pancreatitis is dependent on TH action. Materials & methods: Wild type C57BL/6 mice received serial injections of cerulein to induce pancreatitis; TH levels were altered in vivo by either T3 supplementation or pharmacological hypothyroidism. A panel of selective inhibitors were injected in vivo in combination with T3 to investigate the molecular mechanism beyond T3 action. Levels of cell proliferation, inflammation and dedifferentiation were investigated through immunohistochemistry as well as gene expression analysis. Serum THs' levels were quantified by biochemical analyses. Results: Gene expression analysis revealed a pancreas specific regulation of TH pathway following acute pancreatitis. Hypothyroid mice showed significant impairment in acinar cell proliferation following cerulein treatment and T3 supplementation was able to rescue this phenotype by inducing acinar cell proliferation without increasing damage or inflammation. Gene expression as well as immune assays revealed upregulation of AKT, histone deacetylases (HDACs) and b-catenin following T3 supplementation; use of selective inhibitors for AKT and HDAC reduced T3 induction of proliferation unveiling their involvement in the pathway.
S11
Conclusion: Endogenous TH pathway is activated following acute pancreatitis and drives acinar cell proliferation. Moreover we found that T3 driven acinar cell proliferation is dependent on AKT and HDAC action. All together our data define an important role of TH in pancreas homeostasis and regeneration.
Abstract ID: 1430. A comparison of transverse and midline incisions for pancreaticoduodenectomy Pooja Prasad, James Hodson, Chris Coldham, Ravi Marudanayagam, John R. Isaac, Robert P. Sutcliffe, Paolo Muiesan, Darius F. Mirza, Keith J. Roberts University Hospitals Birmingham, NHS Foundation Trust, United Kingdom Introduction: Various technical aspects of pancreaticoduodenectomy (PD) contribute towards the significant morbidity and mortality associated with this procedure. One aspect of surgical technique is the type of incision utilised. PD may be performed via a transverse subcostal or a midline incision. Aims: We sought to evaluate the clinical outcomes amongst a consecutive cohort of patients undergoing PD at our unit, stratified by incision type. Patients & methods: Consecutive patients undergoing PD were identified from a prospectively maintained database from January 2012 to May 2015. Patient variables, intraoperative data, analgesic usage, pain scores and post-operative complications (including incisional hernia) were obtained from electronic hospital records, and compared between the incision types. Results: Amongst 231 patients undergoing PD, 160 and 71 patients underwent PD via transverse and midline incisions respectively. There was no significant difference between the incision types for any patient or perioperative variables considered, with the exception of the nature of pancreaticoenteric anastomosis. The incision type was not found to have a significant effect on the reporting of severe pain postoperatively (p¼0.642), with an odds ratio for midline, relative to transverse, of 1.10 (95% CI: 0.73 e 1.66). No post-operative physiological parameter was related to the incision type. There was no significant difference in the development of incisional hernias (p¼0.247), with rates at one year of 14.5% and 16.8% in the midline and transverse incision groups, respectively. Conclusion: This study found no evidence to suggest that the type of incision used to perform PD has any significant impact on the development of post-operative complications.
Abstract ID: 1434, Oral-48. The hypothalamic neuropeptide, orexin, prevents chronic pancreatitis in cerulein mice model Anne Couvelard 1, Vinciane Rebours 2, Christopher Prochasson 3, ephanie Dayot 3, Thierry Voisin 3, Maxime Bergere 3, Nassima Messal 3, St Alain Couvineau 3 1
Pathological Unit, Bichat Hospital, Paris, France Pancreatology Unit, Beaujon Hospital, Clichy, France 3 Paris 7, Paris, France INSERM UMR1149, Universite 2
Introduction: Chronic pancreatitis leads to the permanent deterioration of the structure and function of the pancreas characterized by inflammation, fibrosis and exocrine/endocrine insufficiency. Orexins (orexin-A and orexin-B) are hypothalamic peptides involved in the sleep/ wake control which interact with two GPCR sub-types, OX1R and OX2R. We have recently observed that OX1R is highly expressed in acinar and ductal cells in all human pancreatitis tested. Moreover, we have demonstrated the anti-inflammatory role of orexin-A in ulcerative colitis.