Ptf1a/p48 is a pancreas specific bHLH transcription factor that is required at early stages of embryonic development for pancreas formation and, during adulthood, for the proper exocrine pancreatic function. P48 also exerts an antiproliferative effect, which may exert a tumor suppressor activity. In this study, based on a yeast two-hybrid approach, we have identified new p48 partners that modulate the activity of p48. Among the newly identified putative interactors we found p/CAF, which is a coactivator that potentiates its transcriptional activity, and ICAT, an inhibitor of the β-catenin/TCF signaling pathway. ICAT binds to p48 and is coexpressed with it in the pancreas during development and postnatally. Using different cellular models, ICAT overexpression in acinar tumor cells resulted in changes of the pancreatic specific gene expression pattern. Furthermore, high levels of ICAT inhibited the interaction between p48 and p/CAF. While this hetero-oligomeric complex is required for the acinar gene expression, ICAT itself is shown to be present in a reconstituted PTF1 complex in vivo. Importantly, altered ICAT expression is demonstrated in several histological types of pancreatic tumors, possibly contributing to their differentiation phenotype and neoplastic properties. / Ptf1a/p48 es un factor de transcripción bHLH específico del páncreas necesario durante los estadios tempranos del desarrollo embrionario para la formación del mismo, y para el correcto funcionamiento del páncreas exocrino en el adulto. P48 desempeña también una función antiproliferativa, la cual puede resultar en una actividad de supresión tumoral. En el presente estudio, basado en una estrategia de cribado de doble-híbrido en levadura, han sido identificadas nuevas proteínas que interaccionan y que modulan la actividad específica de p48. Entre las posibles proteínas que interaccionan y han sido identificadas de novo se encuentra p/CAF, un co-activador que potencia la actividad transcripcional de p48, y ICAT, un inhibidor de la vía de señalización de la β-catenina. Se ha demostrado que ICAT se une a p48 y ambos son co-expresados en el páncreas durante el desarrollo y en el adulto. Utilizando diferentes modelos celulares, la sobreexpresión de ICAT en células tumorales acinares resultó en un cambio en el patrón de expresión de genes específicos del páncreas. Al mismo tiempo, se observó que niveles elevados de ICAT inhiben la interacción entre p48 y su co-activador p/CAF. Mientras que este complejo hetero-oligomérico es necesario para la expresión de los genes acinares, se demostró que ICAT está presente en un complejo PTF1 reconstituido in vivo. Finalmente, se observaron alteraciones en la expresión de ICAT en varios tipos histológicos de tumores pancreáticos, que posiblemente contribuyen a su fenotipo de diferenciación y propiedades neoplásicas.

Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

Le pancréas est un organe hétérogène composé d’une partie exocrine, responsable de la synthèse d’enzymes pour la digestion, et d’une partie endocrine, essentielle pour l’homéostasie glucidique. Notamment la sécrétion d’insuline par les cellules β contrôle la glycémie. Les dysfonctionnements des cellules β sont une des causes du diabète, première épidémie non infectieuse au monde. Il est actuellement possible d’en traiter les symptômes mais pas de le guérir. De nombreux laboratoires recherchent un protocole idéal de production de cellules β afin de pouvoir greffer ces cellules aux patients. L’identification des facteurs qui gouvernent chaque étape du développement des cellules β devrait permettre de progresser dans ce sens. Le but de ma thèse a été d’étudier le rôle des Espèces Réactives de l’Oxygène (ROS) au cours du développement pancréatique. Cette question a été soulevée lorsque nous avons analysé l’expression des gènes codant pour les enzymes détoxifiantes des ROS: leur expression était extrêmement réduite dans les pancréas embryonnaires comparés aux pancréas adultes, suggérant que les précurseurs sont particulièrement sensibles aux variations des ROS. Nous avons ensuite montré que la réduction des ROS in vivo, obtenue par un traitement avec un antioxydant (NAC), diminue le développement des cellules β. Une analyse in vitro a permis de détailler les mécanismes de l’action des ROS. En effet, le peroxyde d’hydrogène favorise la différenciation des cellules β en augmentant l’expression du facteur pro-endocrine Ngn3 dans les progéniteurs. Ce processus implique l’activation la voie ERK1/2 par les ROS. Au contraire, la diminution des ROS induite par des méthodes génétiques ou pharmacologiques altère la différenciation des cellules β. Nos résultats indiquent également que la mitochondrie est impliquée dans ce processus. Nous avons donc montré que la présence des ROS est essentielle pour le bon développement du pancréas. Ces recherches devraient donc permettre de progresser vers une thérapie cellulaire du diabète. / The pancreas is an heterogenous gland composed by exocrine tissue, responsible for digestive enzyme secretions, and endocrine tissue, essential for glucose homeostasis. In particular β cells secrete insulin which controls glycemia. Moreover, β cell failure is one of the primary causes of diabetes and this pathology is nowadays considered as the first non infectious worldwide outbreak. There is unfortunately no cure for this disease. Many laboratories are currently improving β cell generation protocols in order to inject those cells into patients. This is the reason why it appears mandatory to be able to identify factors that govern each step of β cell development. The aim of my work was to study the role of the Reactive Oxygen Species (ROS) during pancreatic development. First we found out that the expression of genes coding for antioxidant enzymes was extremely low in embryonic pancreas compared to adult pancreas. This suggested that progenitors could be sensitive to ROS variations. We then showed in vivo using an antioxidant component (NAC) that decreasing ROS level diminishes β cell development. Analysis in vitro allowed us to better describe the role of ROS. Indeed, hydrogen peroxyde favors β cell differentiation by increasing the pro-endocrine marker NGN3 expression in the progenitors. In this process, ROS activate the ERK1/2 signaling pathway. On the contrary, lowering ROS level using both pharmacologic and genetic approaches, decreases β cell differentiation. Our results also point out a role of the mitochondria in this process. Altogether, our data define the effects of ROS on β cell differentiation and open new perspectives to improve protocols of β cell generation.

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment are needed. Recent advances in human genome research and high-throughput molecular technologies make it possible to cope with the molecular complexity of malignant tumors. With DNA array technology, mRNA expression levels of thousand of genes can be measured simultaneously in a single assay. As several studies using microarrays in PDAC have already been published, this review attempts to compare the published data and therefore to validate the results. In addition, the applied techniques are discussed in the context of pancreatic malignancies. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Le pancréas est un organe hétérogène composé d’une partie exocrine, responsable de la synthèse d’enzymes pour la digestion, et d’une partie endocrine, essentielle pour l’homéostasie glucidique. Notamment la sécrétion d’insuline par les cellules β contrôle la glycémie. Les dysfonctionnements des cellules β sont une des causes du diabète, première épidémie non infectieuse au monde. Il est actuellement possible d’en traiter les symptômes mais pas de le guérir. De nombreux laboratoires recherchent un protocole idéal de production de cellules β afin de pouvoir greffer ces cellules aux patients. L’identification des facteurs qui gouvernent chaque étape du développement des cellules β devrait permettre de progresser dans ce sens. Le but de ma thèse a été d’étudier le rôle des Espèces Réactives de l’Oxygène (ROS) au cours du développement pancréatique. Cette question a été soulevée lorsque nous avons analysé l’expression des gènes codant pour les enzymes détoxifiantes des ROS: leur expression était extrêmement réduite dans les pancréas embryonnaires comparés aux pancréas adultes, suggérant que les précurseurs sont particulièrement sensibles aux variations des ROS. Nous avons ensuite montré que la réduction des ROS in vivo, obtenue par un traitement avec un antioxydant (NAC), diminue le développement des cellules β. Une analyse in vitro a permis de détailler les mécanismes de l’action des ROS. En effet, le peroxyde d’hydrogène favorise la différenciation des cellules β en augmentant l’expression du facteur pro-endocrine Ngn3 dans les progéniteurs. Ce processus implique l’activation la voie ERK1/2 par les ROS. Au contraire, la diminution des ROS induite par des méthodes génétiques ou pharmacologiques altère la différenciation des cellules β. Nos résultats indiquent également que la mitochondrie est impliquée dans ce processus. Nous avons donc montré que la présence des ROS est essentielle pour le bon développement du pancréas. Ces recherches devraient donc permettre de progresser vers une thérapie cellulaire du diabète. / The pancreas is an heterogenous gland composed by exocrine tissue, responsible for digestive enzyme secretions, and endocrine tissue, essential for glucose homeostasis. In particular β cells secrete insulin which controls glycemia. Moreover, β cell failure is one of the primary causes of diabetes and this pathology is nowadays considered as the first non infectious worldwide outbreak. There is unfortunately no cure for this disease. Many laboratories are currently improving β cell generation protocols in order to inject those cells into patients. This is the reason why it appears mandatory to be able to identify factors that govern each step of β cell development. The aim of my work was to study the role of the Reactive Oxygen Species (ROS) during pancreatic development. First we found out that the expression of genes coding for antioxidant enzymes was extremely low in embryonic pancreas compared to adult pancreas. This suggested that progenitors could be sensitive to ROS variations. We then showed in vivo using an antioxidant component (NAC) that decreasing ROS level diminishes β cell development. Analysis in vitro allowed us to better describe the role of ROS. Indeed, hydrogen peroxyde favors β cell differentiation by increasing the pro-endocrine marker NGN3 expression in the progenitors. In this process, ROS activate the ERK1/2 signaling pathway. On the contrary, lowering ROS level using both pharmacologic and genetic approaches, decreases β cell differentiation. Our results also point out a role of the mitochondria in this process. Altogether, our data define the effects of ROS on β cell differentiation and open new perspectives to improve protocols of β cell generation.

Introdução: O transplante de pâncreas é uma opção terapêutica para pacientes portadores de diabetes mellitus, quando bem indicado, com objetivo de restaurar a normoglicemia sem necessidade de uso de insulina, sendo que a técnica mais utilizada é o transplante simultâneo pâncreas-rim. Houve aumento da indicação e realização deste procedimento em todo o mundo nos últimos anos, crescendo a importância de se conhecer os aspectos de imagem no pré e pós-transplante de pâncreas. Objetivos: Avaliar e discutir o papel das diferentes modalidades de exames de imagem empregadas na avaliação no pré e pós-transplante de pâncreas enfatizando os achados normais e das possíveis complicações. Propor um fluxograma para realização de exames de imagem para o programa de transplante de pâncreas considerando a casuística apresentada. Metodologia: Levantamento retrospectivo dos métodos de imagem com as indicações e os achados pré e pós-procedimento em todos os pacientes submetidos a transplante de pâncreas no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, da Universidade de São Paulo. Resultados: Foram estudados 14 casos com indicação de transplante simultâneo pâncreasrim, 13 destes submetidos ao transplante no período 2010-2016, os quais apresentaram idade média de 37,6 +/- 6,2 anos (variando entre 24 e 51 anos), sendo 8 (57%) do sexo masculino e 6 (42%) do sexo feminino. Um (7,2%) paciente não pode receber o enxerto pancreático devido a procedimento cirúrgico frustro resultante de diagnóstico intra-operatório de placa ateromatosa extensa. As complicações pós-transplante mais comuns foram: coleções na 7 cavidade abdominal (6/13 casos (46,1%)), pancreatite (6/13 (46,1%)) e complicações vasculares (4/13 (30,8%)). O US com Doppler foi realizado no pós-operatório em todos os casos. Conclusões: há necessidade de avaliação vascular pré-operatória por imagem do receptor, de rotina, para evitar problemas no momento do transplante. O TSPR tem alto risco de complicações, sendo necessária a retirada do enxerto em número relativamente grande dos casos. A avaliação pelos métodos de imagem foi fundamental para o diagnóstico e planejamento do tratamento das complicações, sendo que o US com Doppler se mostrou suficiente como primeiro exame. A correlação com angioTC e(ou) angioRM foi necessária nos casos com suspeita de complicação vascular, permitindo confirmar a suspeita em todos os casos. / Introduction: Pancreas transplantation is a therapeutic option for patients with diabetes mellitus, when well indicated, to restore normoglycemia with no need of insulin, and the most commonly used technique is simultaneous pancreas-kidney transplantation. There has been an increase in the indication and performance of this procedure worldwide in recent years, increasing the importance of knowing the aspects of imaging in the pre- and posttransplantation of pancreas. Objectives: To evaluate and discuss the role of the different imaging modalities used in the assessment in the pre- and post transplantation of the pancreas emphasizing the normal findings and the possible complications. To propose a flowchart to perform imaging tests for the pancreas transplantation program considering the presented case series. Methodology: Retrospective survey of imaging methods with pre and post-procedure indications and findings in all patients undergoing pancreas transplantation at Hospital das Clínicas, Ribeirão Preto Medical School, University of São Paulo. Results: We studied 14 cases with simultaneous pancreas-kidney transplantation, 13 of them undergoing transplantation in the period 2010-2016, which presented a mean age of 37.6 +/- 6.2 years (ranging from 24 to 51 years), of which 8 (57%) were male and 6 (42%) were female. One (7,2%) patient could not receive the pancreatic graft due to the frustrating surgical procedure resulting from an intraoperative diagnosis of extensive atheromatous plaque. The most common post-transplant complications were collections in the abdominal 9 cavity (6/13 cases (46.1%)), pancreatitis (6/13 (46.1%)) and vascular complications (4/13 (30.8% )). The US with Doppler was performed postoperatively in all cases. Conclusions: There is a need for routine preoperative vascular imaging of the recipient to avoid problems at the time of transplantation. TSPR has a high risk of complications, requiring removal of the graft in a relatively large number of cases. The evaluation by the imaging methods was fundamental for the diagnosis and planning of the treatment of the complications, and the US with Doppler was sufficient as the first examination. Correlation with angioTC and (or) angioRM was necessary in cases with suspected vascular complications, allowing confirmation of suspicion in all cases.

Diese Dissertation analysiert zum ersten Mal STARD13, ein Protein mit einer RhoGAP-Domäne, und dessen Rolle als essentiellen Regulator der Pankreasarchitektur im Mausembryo. Es wird gezeigt, dass Stard13 anfangs im pankreatischen Endoderm exprimiert wird und später in den “Epithelspitzen” angereichert ist. Konditionelle Ablation von Stard13 im Mauspankreas beeinflusst die normale Epithelmorphogenese und die Organisation der “Epithelspitzen”. Das beeinträchtigt die Proliferation der Pankreasvorläuferzellen und führt zu Organhypoplasie. Dabei reguliert STARD13 örtlich und zeitlich Rho-Signale, die für die Morphogenese essentiell sind. Desweiteren werden die Mechanismen, die für die Entwicklung des Pankreasepithels in ein funktionierendes Organ notwendig sind, neu beleuchtet. Es wird zum Beispiel eine funktionelle Verbindung zwischen Rho-vermittelter Kontrolle der Epithelumgestaltung und der Determinierung der Organgröße hergestellt. Dabei spielt die reziproke Interaktion von actin-MAL-SRF and MAPK Signalen eine wichtige Rolle. / The development of functional organ architecture relies on coordinated morphogenesis and growth. In the developing pancreas, the branching epithelium is organized in discrete domains that delineate one specific domain of progenitor cells at the tip of the branches. Very little is known about branching morphogenesis in the pancreas and how it is coordinated with proliferation. This thesis presents the first analysis of the RhoGAP-domain-containing protein STARD13 and its role as an essential regulator of pancreas tissue architecture in the mammalian embryo. It is shown that Stard13 is expressed in the pancreatic endoderm and enriched at the distal tip of the branching epithelium. Conditional ablation of Stard13 expression in the mouse pancreas disrupts epithelial morphogenesis and tip domain organization, resulting in hampered proliferation of pancreatic progenitors and subsequent organ hypoplasia. Stard13 acts by regulating Rho signaling spatially and temporally during pancreas development. This thesis provides new insights into the mechanisms that shape pancreatic epithelium to create a mature organ and establishes a functional link between Rho-mediated control of epithelial remodeling and organ size determination, involving reciprocal interaction of actin-MAL-SRF and MAPK signaling.

Le pancréas est un organe hétérogène composé d’une partie exocrine, responsable de la synthèse d’enzymes pour la digestion, et d’une partie endocrine, essentielle pour l’homéostasie glucidique. Notamment la sécrétion d’insuline par les cellules β contrôle la glycémie. Les dysfonctionnements des cellules β sont une des causes du diabète, première épidémie non infectieuse au monde. Il est actuellement possible d’en traiter les symptômes mais pas de le guérir. De nombreux laboratoires recherchent un protocole idéal de production de cellules β afin de pouvoir greffer ces cellules aux patients. L’identification des facteurs qui gouvernent chaque étape du développement des cellules β devrait permettre de progresser dans ce sens. Le but de ma thèse a été d’étudier le rôle des Espèces Réactives de l’Oxygène (ROS) au cours du développement pancréatique. Cette question a été soulevée lorsque nous avons analysé l’expression des gènes codant pour les enzymes détoxifiantes des ROS: leur expression était extrêmement réduite dans les pancréas embryonnaires comparés aux pancréas adultes, suggérant que les précurseurs sont particulièrement sensibles aux variations des ROS. Nous avons ensuite montré que la réduction des ROS in vivo, obtenue par un traitement avec un antioxydant (NAC), diminue le développement des cellules β. Une analyse in vitro a permis de détailler les mécanismes de l’action des ROS. En effet, le peroxyde d’hydrogène favorise la différenciation des cellules β en augmentant l’expression du facteur pro-endocrine Ngn3 dans les progéniteurs. Ce processus implique l’activation la voie ERK1/2 par les ROS. Au contraire, la diminution des ROS induite par des méthodes génétiques ou pharmacologiques altère la différenciation des cellules β. Nos résultats indiquent également que la mitochondrie est impliquée dans ce processus. Nous avons donc montré que la présence des ROS est essentielle pour le bon développement du pancréas. Ces recherches devraient donc permettre de progresser vers une thérapie cellulaire du diabète. / The pancreas is an heterogenous gland composed by exocrine tissue, responsible for digestive enzyme secretions, and endocrine tissue, essential for glucose homeostasis. In particular β cells secrete insulin which controls glycemia. Moreover, β cell failure is one of the primary causes of diabetes and this pathology is nowadays considered as the first non infectious worldwide outbreak. There is unfortunately no cure for this disease. Many laboratories are currently improving β cell generation protocols in order to inject those cells into patients. This is the reason why it appears mandatory to be able to identify factors that govern each step of β cell development. The aim of my work was to study the role of the Reactive Oxygen Species (ROS) during pancreatic development. First we found out that the expression of genes coding for antioxidant enzymes was extremely low in embryonic pancreas compared to adult pancreas. This suggested that progenitors could be sensitive to ROS variations. We then showed in vivo using an antioxidant component (NAC) that decreasing ROS level diminishes β cell development. Analysis in vitro allowed us to better describe the role of ROS. Indeed, hydrogen peroxyde favors β cell differentiation by increasing the pro-endocrine marker NGN3 expression in the progenitors. In this process, ROS activate the ERK1/2 signaling pathway. On the contrary, lowering ROS level using both pharmacologic and genetic approaches, decreases β cell differentiation. Our results also point out a role of the mitochondria in this process. Altogether, our data define the effects of ROS on β cell differentiation and open new perspectives to improve protocols of β cell generation.

Há um número crescente de pessoas e animais com obesidade e sobrepeso, com consequente aumento no número de pacientes resistentes à insulina e portadores de Diabetes mellitus (DM). O fator de crescimento vascular endotelial (VEGF) tem sido caracterizado como uma molécula importante em inúmeros mecanismos fisiopatológicos. Em diabéticos, pesquisas indicam uma redução deste fator em alguns tecidos estudados, sendo esta menor expressão envolvida com o desenvolvimento de hipóxia tecidual e não cicatrização de feridas. Neste contexto, este trabalho teve como objetivos caracterizar um modelo diabético induzido por dieta, avaliar a vascularização, expressão gênica e proteica do VEGFA e seus receptores FLT1 e KDR em pâncreas de camundongos diabéticos e não diabéticos, antes e após a terapia gênica com VEGF. O estudo consistiu de 2 fases para as quais foram utilizados cinquenta camundongos, na primeira fase foram utilizados 28 animais distribuídos em 6 grupos experimentais: submetidos à dieta controle (CT) e dieta hipercalórica (DH) por 3, 4 e 6 meses. Na segunda fase, 4 grupos experimentais foram avaliados aos 4 meses: CT e DH sem vetor terapêutico (CTPLL e DHPLL) e CT e DH com vetor terapêutico (CTVEGF e DHVEGF). A análise gênica pelo PCR em tempo real e proteica pela imuno-histoquímica evidenciou queda na expressão de VEGF, FLT1 e KDR no grupo DH, sendo que a variável estereológica de densidade de volume vascular (Vv) indicou queda significativa (p<0,05) da vascularização pancreática no grupo DH em relação ao CT aos 3, 4 e 6 meses do estudo. O DM foi caracterizado com queda significativa (p<0,05) na insulinemia após 4 meses com DH. Após a injeção pancreática no grupo DHVEGF do lentivírus contendo a sequência que condifica o VEGF, foram observados aumento na expressão gênica de VEGF , FLT1 e KDR (p<0,05), com aumento de Vv vascular pancreático e aumento na insulinemia. Os resultados obtidos sugerem que é possível obter um modelo animal diabético induzido por dieta, que o VEGF e seus receptores participam da evolução e estabelecimento do quadro diabético, levando a uma redução da vascularização pancreática, e que o aumento na expressão do transgene no pâncreas de camundongos diabéticos possa contribuir para a revascularização pancreática e função das células B. / There is an increasing number of people and pets showing overweight and obesity, with a consequent growth of the number of insulin-resistant and diabetic patients. The vascular endothelial growth factor (VEGF) has been characterized as an important molecule in many physiopathological states. Recent studies indicate a reduction in VEGF content in some tissues of diabetic patients causing tissue hypoxia and impairing cicatrization. In this context, this study aimed to characterize a diet-induced diabetic animal model and to evaluate vascularization, gene and protein expression of VEGFA and its receptors KDR and FLT1, in pancreas of diabetic and non-diabetic mice before and after gene therapy with VEGF. The study was divided in two phases and fifty male mice were used. In the first phase 28 animals were distributed into 6 groups: control diet (CT) and high calorie diet (DH) for 3, 4 and 6 months. In the second phase, four experimental groups were evaluated at 4 months: CT and DH without therapeutic vector (CTPLL and DHPLL) and CT and DH with therapeutic vector (CTVEGF and DHVEGF). The genetic analysis using real time PCR and protein by immunohistochemistry showed decrease in expression of VEGF, FLT1 and KDR in the DH group, and the stereological estimate of vascular volume density (Vv) indicated a significant decrease (p <0,05 ) of vascularization in pancreatic DH group relative to the CT at 3, 4 and 6 months of the study. Diabetic mice were characterized with a significant decrease (p <0,05) in insulin after 4 months with DH. After injection of lentivirus containing the VEGF sequence in DHVEGF´s pancreas, increase in VEGF, FLT1 and KDR gene expression (p <0.05) was observed, accompanied by the increase of vascular Vv and insulinemia. The results suggest that it is possible to obtain a diabetic animal model induced by diet, that VEGF and its receptors participate in the development and establishment of the diabetic state, leading to a reduction of pancreas vascularization, and that the increase of transgene expression in the pancreas of diabetic mice may contribute to the revascularization and function of pancreatic B cells.

INTRODUÇÃO: O câncer do pâncreas apresenta taxas anuais de mortalidade e incidência muito semelhantes, sendo uma das principais causas de morte por câncer no mundo. A agressividade do tumor e o retardo no seu diagnóstico são considerados responsáveis pela sua alta letalidade. O tratamento adjuvante convencional aumenta pouco a sobrevida a longo prazo e a terapia-alvo pode ser uma alternativa ao tratamento deste tipo de tumor. OBJETIVO: O objetivo do presente estudo é avaliar a expressão do receptor do fator de crescimento epitelial e seu eventual valor prognóstico em pacientes portadores de adenocarcinoma pancreático submetidos à ressecção cirúrgica. MÉTODO: Foram estudados retrospectivamente 88 pacientes portadores de adenocarcinoma pancreático operados no Serviço de Cirurgia de Vias Biliares e Pâncreas do HC-FMUSP e no Departamento de Cirurgia Abdominal Hospital A.C. Camargo no período de 1990 a 2006. RESULTADOS: Quarenta e sete (53,4%) pacientes do sexo feminino e 41 (46,6%) do masculino com idade mediana de 60 anos. As cirurgias realizadas foram duodenopancreatectomia com preservação do piloro (55,1%), gastroduodenopancreatectomia (34,8%), pancreatectomia corpo-caudal (6,8%) e gastroduodenopancreatectomia total (2,3%). A ressecção venosa portal foi realizada em 12 pacientes (13,5%). O tamanho tumoral médio foi de 3,75cm. Invasão vascular esteve presente em 31% dos casos e neural em 88,5%. A margem de ressecção estava comprometida em 33 pacientes (37,5%). Cinco (5,7%) pacientes eram do estádio IA, 15(17%) do IB, 19(21,6%) do IIA, 47(53,4) do IIB e dois (2,3%) do III.Observou-se diferença na expressão de EGFR na membrana celular entre o tecido tumoral e o tecido não tumoral (p=0,004); entre o tecido metastático linfonodal e o tecido não tumoral (p=0,02) mas não houve diferença quanto à sua expressão quando comparamos o tecido tumoral e o tecido metastático linfonodal (p=0,28). Dentre as variáveis clínicas e patológicas estudadas, observou-se diferença de expressão do EGFR entre os gêneros feminino e masculino (p=0,03), não havendo diferenças entre as outras variáveis. A sobrevida mediana global foi de 22,9 meses. A sobrevida cumulativa global em 1 ano, 3 anos e 5 anos foi de 48%, 20% e 18%, respectivamente. As sobrevidas cumulativas em 1 ano, 3 anos e 5 anos foram 77%, 30% e 8% no grupo sem expressão do EGFR na membrana tumoral versus 46%, 8% e 0% respectivamente no grupo com expressão do EGFR na membrana celular do tumor. Na análise univariada, as seguintes variáveis estiveram associadas a menor sobrevida: sexo masculino, ressecção venosa portal, invasão peri-neural, e vascular, invasão do tecido peri-pancreático, acometimento da margem de ressecção pancreática e expressão positiva de EGFR no tecido tumoral. Na análise multivariada, os fatores associados à sobrevida menor foram: gênero masculino, ressecção venosa portal, invasão vascular e invasão peri-neural. CONCLUSÃO: A expressão do EGFR na membrana celular é significativamente maior no tecido tumoral que no tecido pancreático não tumoral. A expressão do EGFR na membrana celular do tecido tumoral está associada a pior prognóstico (menor sobrevida). / INTRODUCTION: Pancreatic cancer is one of the main cancer related deaths in the world and its incidence is similar to its mortality. Biological aggressiveness and delayed diagnosis are a major concern. Adjuvant treatment has little impact on survival and the expression of potential target molecules has been undertaken in order to increase survival. OBJECTIVE: The aim of the present study is to study the expression of EGFR and its potential prognostic role in tumor, non-tumor and metastatic lymph node tissues of patient with pancreatic adenocarcinoma treated with surgical resection. MATHERIAL AND METHODS: Eighty eight patients with pancreatic adenocarcinoma operated at Serviço de Cirurgia de Vias Biliares e Pâncreas do HC-FMUSP and Departamento de Cirurgia Abdominal do Hospital A.C.Camargo were retrospectively studied between 1990 and 2003. RESULTS: Forty seven females (53,4%) and 41 males (46,6%) with median age of 60 years were studied. Pylorus preserving duodenopancreatectomy was performed in 55%, classical duodenopancreatectomy in 34,8%, distal pancreatectomy in 6,8% and total pancreatectomy in 2,3%. Portal vein resection was performed in 12 patients (13,5%). Mean tumor size was 3,75cm. Vascular and neural invasion were present in 31% and 88,5%, respectively. Positive surgical margin was present in 33 (37,5%) patients. Five (5,7%) patients were stage IA, 15(17%) stages IB, 19(21,6%) stages IIA, 47(53,4%) stages IIB and two (2,3%) stages III. There were difference in the membrane expression of EGFR between tumor and non tumor pancreatic tissue (p=0,004); between metastatic lymph node and non tumor pancreatic tissue (p=0,02); but there were no difference between tumor and metastatic lymph node tissue (p=0,28). Median survival time was 22,9 months. Cumulative one, three and five years survival were 48%, 20% and 18%. Cumulative survival at 1, 3 and 5 years were 77%, 30% and 8% in patients with negative expression of EGFR in tumor membrane and 46%, 8% and 0%, respectively in patients with positive EGFR expression in tumoral membrane. Univariate analysis showed that male gender, portal vein resection, neural, vascular and peri-pancreatic invasion invasion, positive surgical margin and positive membrane EGFR expression in tumoral tissue were correlated with poor survival. Multivariate analysis showed that male gender, portal vein resection, vascular invasion and peri-neural invasion are associated with lower survival after resection. CONCLUSION: EGFR membrane expression is different between tumor tissue and non tumor pancreatic tissue. EGFR membrane expression in tumoral tissue was associated with worst survival.