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Pancreatic Neoplasms: HELP
Articles by Mert M. Erkan
Based on 43 articles published since 2010
(Why 43 articles?)
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Between 2010 and 2020, Mert Erkan wrote the following 43 articles about Pancreatic Neoplasms.
 
+ Citations + Abstracts
Pages: 1 · 2
1 Review Contemporary strategies to improve the outcome in locally advanced pancreatic cancer. 2017

Schneider, Rick / Späth, Christoph / Nitsche, Ulrich / Erkan, Mert / Kleeff, Jörg. ·Department of Visceral, Vascular and Endocrine Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany. · Department of General Surgery, North Shore Hospital, Auckland, New Zealand. · Department of Surgery, Rechts der Isar Hospital, Technical University of Munich, Munich, Germany. · Department of Surgery, Koç University School of Medicine, Istanbul, Turkey. · Department of Visceral, Vascular and Endocrine Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany - joerg.kleeff@uk-halle.de. ·Minerva Chir · Pubmed #28565894.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an overall 5-year survival rate of less than 7%. After many years of basic and clinical research efforts, pancreatic cancer patients presenting with locally advanced, unresectable tumors remain a therapeutic challenge. Despite the lack of high quality randomized controlled trials, perioperative/neoadjuvant treatment strategies seem to be beneficial in these patients. At present the FOLFIRINOX regimen, which was established in the palliative setting, is increasingly recognized as the backbone of neoadjuvant therapy for locally advanced PDAC. Surgical resection follows the same principles and guidelines as upfront surgery specifically regarding the extent of resection including lymphadenectomy, vascular resections and multivisceral resections. Because of the limited diagnostic accuracy of restaging after neoadjuvant treatment, an adjusted intraoperative strategy is necessary to minimize the risk of debulking procedures and maximize the chance of a potential curative resection. Locally advanced PDAC requires a multidisciplinary and individualized treatment approach, and further research efforts for novel and innovative therapies. This article provides an updated overview on strategies to improve the outcome in locally advanced PDAC.

2 Review The role of hypoxia in pancreatic cancer: a potential therapeutic target? 2016

Erkan, Mert / Kurtoglu, Metin / Kleeff, Jorg. ·a Department of Surgery , Koç University School of Medicine , Istanbul , Turkey. · b Department of Oncology , Koç University School of Medicine , Istanbul , Turkey. · c Department of Surgery , The Royal Liverpool and Broadgreen University Hospitals , Liverpool , UK. · d Department of General-, Visceral- and Pediatric Surgery , University Hospital Düsseldorf, Heinrich Heine University Düsseldorf , Düsseldorf , Germany. ·Expert Rev Gastroenterol Hepatol · Pubmed #26560854.

ABSTRACT: One of the key factors that correlates with poor survival of patients with pancreatic cancer is the extent of hypoxic areas within the tumor tissue. The adaptation of pancreatic cancer cells to limited oxygen delivery promotes the induction of an invasive and treatment-resistant phenotype, triggering metastases at an early stage of tumor development, which resist in most cases adjuvant therapies following tumor resection. In this article, the authors summarize the evidence demonstrating the significance of hypoxia in pancreatic cancer pathogenesis and discuss the possible hypoxia-induced mechanisms underlying its aggressive nature. We then conclude with promising strategies that target hypoxia-adapted pancreatic cancer cells.

3 Review The role of inflammation in pancreatic cancer. 2014

Hausmann, Simone / Kong, Bo / Michalski, Christoph / Erkan, Mert / Friess, Helmut. ·Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, 81675, Munich, Germany. ·Adv Exp Med Biol · Pubmed #24818722.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an extremely poor prognosis. Inflammatory processes have emerged as key mediators of pancreatic cancer development and progression. In genetically engineered mouse models, induction of pancreatitis accelerates PDAC development, and patients with chronic pancreatitis are known to have a higher risk of developing pancreatic cancer. In recent years, much effort has been given to identify the underlying mechanisms that contribute to inflammation-induced tumorigenesis. Many inflammatory pathways have been identified and inhibitors have been developed in order to prevent cancer development and progression. In this chapter, we discuss the role of inflammatory pathways in the initiation and progression of pancreatic cancer as well as the role of inhibitors used in treatment and prevention of pancreatic cancer.

4 Review Overview on how oncogenic Kras promotes pancreatic carcinogenesis by inducing low intracellular ROS levels. 2013

Kong, Bo / Qia, Chengjia / Erkan, Mert / Kleeff, Jörg / Michalski, Christoph W. ·Department of Surgery, Technische Universität München Munich, Germany. ·Front Physiol · Pubmed #24062691.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease without clearly known disease causes. Recent epidemiological and animal studies suggest that the supplementation of dietary antioxidants (e.g., vitamins C and E) decreases cancer risk, implying that increased reactive oxygen species (ROS) may play a role in pancreatic carcinogenesis. However, oncogenic Kras mutations (e.g., Kras(G12D)), which are present in more than 90% of PDAC, have been proven to foster low intracellular ROS levels. Here, oncogenic Kras activates expression of a series of anti-oxidant genes via Nrf2 (nuclear factor, erythroid derived 2, like 2) and also mediates an unusual metabolic pathway of glutamine to generate NADPH. This can then be used as the reducing power for ROS detoxification, leading collectively to low ROS levels in pancreatic pre-neoplastic cells and in cancer cells. In adult stem cells and cancer stem cells, low ROS levels have been associated with the formation of a proliferation-permissive intracellular environment and with perseverance of self-renewal capacities. Therefore, it is conceivable that low intracellular ROS levels may contribute significantly to oncogenic Kras-mediated PDAC formation.

5 Review The role of stroma in pancreatic cancer: diagnostic and therapeutic implications. 2012

Erkan, Mert / Hausmann, Simone / Michalski, Christoph W / Fingerle, Alexander A / Dobritz, Martin / Kleeff, Jörg / Friess, Helmut. ·Department of General Surgery, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 12, 81675 Munich, Germany. m.mert.erkan@googlemail.com ·Nat Rev Gastroenterol Hepatol · Pubmed #22710569.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is one of the five most lethal malignancies worldwide and survival has not improved substantially in the past 30 years. Desmoplasia (abundant fibrotic stroma) is a typical feature of PDAC in humans, and stromal activation commonly starts around precancerous lesions. It is becoming clear that this stromal tissue is not a bystander in disease progression. Cancer-stroma interactions effect tumorigenesis, angiogenesis, therapy resistance and possibly the metastatic spread of tumour cells. Therefore, targeting the tumour stroma, in combination with chemotherapy, is a promising new option for the treatment of PDAC. In this Review, we focus on four issues. First, how can stromal activity be used to detect early steps of pancreatic carcinogenesis? Second, what is the effect of perpetual pancreatic stellate cell activity on angiogenesis and tissue perfusion? Third, what are the (experimental) antifibrotic therapy options in PDAC? Fourth, what lessons can be learned from Langton's Ant (a simple mathematical model) regarding the unpredictability of genetically engineered mouse models?

6 Review Energy metabolism and proliferation in pancreatic carcinogenesis. 2012

Regel, Ivonne / Kong, Bo / Raulefs, Susanne / Erkan, Mert / Michalski, Christoph W / Hartel, Mark / Kleeff, Jörg. ·Department of Surgery, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany. ·Langenbecks Arch Surg · Pubmed #22430298.

ABSTRACT: INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer entity with a high proliferative potential. Uncontrolled cell proliferation is mediated by a number of core signaling pathways. Recently, novel data of PDAC biology suggest that these core signal pathways affect cell proliferation and metabolism simultaneously. METHODS: Here, we reviewed the literature on core metabolic signaling pathways in pancreatic carcinogenesis. RESULTS: Results obtained from mouse genetics and in vitro experiments have demonstrated the significance of the Kras, p53, c-Myc, and Lkb1 networks in the proliferation of pancreatic epithelial and cancer cells. At the same time, these major pathways also affect energy metabolism by influencing glucose and glutamine utilization. In particular, Kras-mediated metabolic changes seem to be directly involved in carcinogenesis. However, there is a lack of solid evidence on how metabolism and proliferation are connected in pancreatic carcinogenesis. CONCLUSION: Understanding early and subtle changes in cellular metabolism of pancreatic epithelial-and specifically of acinar-cells, which accompany or directly influence malignant transformation and uncontrolled proliferation, will be paramount to define novel imaging and other modalities for earlier detection of PDAC.

7 Review The impact of the activated stroma on pancreatic ductal adenocarcinoma biology and therapy resistance. 2012

Erkan, Mert / Reiser-Erkan, Carolin / Michalski, Christoph W / Kong, Bo / Esposito, Irene / Friess, Helmut / Kleeff, Jorg. ·Department of General Surgery, Klinikum rechts der Isar, Technische Universität München, Germany. m.mert.erkan@googlemail.com ·Curr Mol Med · Pubmed #22272725.

ABSTRACT: Around 95% of patients diagnosed with pancreatic cancer will die of their disease within 5 years, three quarters within a year. The major hurdle in improving prognosis is the lack of a therapeutic time window. Early cancerous lesions are far beneath our threshold of detection. Therefore, at the time of diagnosis even early (T1) tumors can be metastatic and resistant to conventional treatments. Several therapies targeting epithelial tumor cells-all showing impressive results in vitro and in animal experiments-have failed to show relevant effects in clinical trials. This discrepancy between experimental data and clinical reality results mostly from the inefficiency of our current experimental setups in recreating the tumor microenvironment. Forming more than 80% of the tumor mass, the fibrotic stroma of pancreatic ductal adenocarcinoma is not a passive scaffold for the malignant cells but an active player in carcinogenesis. This component is mostly missing in the xeno-/allograft- mouse models. Although tumors are bigger if stellate cells are co-implanted, due to the disproportionate cancer/stromal cell ratio and -possibly- too rapid tumor growth, the stromal reaction is much smaller than in human pancreatic cancer. One the other hand, desmoplasia is present only in some of the genetically engineered mouse models. Clinically, stromal activity of the pancreatic ductal adenocarcinoma has as great an impact on patient prognosis as the lymph node status of the tumor. The exact molecular mechanisms behind this observation remain obscure. However, one possible fundamental biologic explanation could be that selective pressure applied by the stroma leads to the evolution of cancer cells. Consequently, somatic evolution of invasive cancer could be viewed as a sequence of phenotypical adaptations to this barrier, highlighting the importance of the fibrotic tumor microenvironment in the behavior of pancreatic cancer. In this review, the interaction of the epithelial tumor cells with the stroma in humans and in various animal models is scrutinized, and novel therapeutic options for uncoupling cancer-stroma interactions are discussed.

8 Review From tissue turnover to the cell of origin for pancreatic cancer. 2011

Kong, Bo / Michalski, Christoph W / Erkan, Mert / Friess, Helmut / Kleeff, Jörg. ·Department of Surgery, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany. ·Nat Rev Gastroenterol Hepatol · Pubmed #21750515.

ABSTRACT: The identity of the cell of origin for pancreatic ductal adenocarcinoma (PDAC) has long been debated. PDAC has a ductal morphology, but there is no formal proof that it originates from the ductal compartment. Targeting Kras expression to adult acinar or endocrine lineages induces the formation of tumors reminiscent of human PDAC, but only in the presence of concomitant inflammation. Apart from cells of the Pdx1-positive lineage in the adult pancreas, which can be transformed (albeit with low frequency), the cells susceptible to acquiring or retaining oncogenic mutations remain elusive. Hypothetically, a subset of cells that renew the adult organ physiologically or regenerate it upon severe tissue damage would be more susceptible to oncogenic transformation than mature, differentiated cells. Such a compartment could consist of putative pancreatic stem cells, progenitor cells, facultative stem cells or transdifferentiated bone marrow cells. An integrated approach combining techniques from stem cell and cancer biology will be necessary to define and map these cells.

9 Article Targeting nNOS ameliorates the severe neuropathic pain due to chronic pancreatitis. 2019

Demir, Ihsan Ekin / Heinrich, Tobias / Carty, Dominique G / Saricaoglu, Ömer Cemil / Klauss, Sarah / Teller, Steffen / Kehl, Timo / Mota Reyes, Carmen / Tieftrunk, Elke / Lazarou, Maria / Bahceci, Dorukhan H / Gökcek, Betül / Ucurum, Bahar E / Maak, Matthias / Diakopoulos, Kalliope N / Lesina, Marina / Schemann, Michael / Erkan, Mert / Krüger, Achim / Algül, Hana / Friess, Helmut / Ceyhan, Güralp O. ·Department of Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany; DKTK Munich site, Germany; SFB 1321, Germany. Electronic address: ekin.demir@tum.de. · Department of Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. · Human Biology, Technical University of Munich, Freising, Germany. · Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Department of Surgery, University of Erlangen, Erlangen, Germany. · Department of Internal Medicine II, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. · Institute for Molecular Immunology and Experimental Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. · Department of Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany; DKTK Munich site, Germany; SFB 1321, Germany. ·EBioMedicine · Pubmed #31401195.

ABSTRACT: BACKGROUND: Pain due to pancreatic cancer/PCa or chronic pancreatitis/CP, is notoriously resistant to the strongest pain medications. Here, we aimed at deciphering the specific molecular mediators of pain at surgical-stage pancreatic disease and to discover novel translational targets. METHODS: We performed a systematic, quantitative analysis of the neurotransmitter/neuroenzmye profile within intrapancreatic nerves of CP and PCa patients. Ex vivo neuronal cultures treated with human pancreatic extracts, conditional genetically engineered knockout mouse models of PCa and CP, and the cerulein-induced CP model were employed to explore the therapeutic potential of the identified targets. FINDINGS: We identified a unique enrichment of neuronal nitric-oxide-synthase (nNOS) in the pancreatic nerves of CP patients with increasing pain severity. Employment of ex vivo neuronal cultures treated with pancreatic tissue extracts of CP patients, and brain-derived-neurotrophic-factor-deficient (BDNF INTERPRETATION: We propose nNOS inhibition as a novel strategy to treat the unbearable pain in CP. FUND: Deutsche Forschungsgemeinschaft/DFG (DE2428/3-1 and 3-2).

10 Article Mutant KRAS-driven cancers depend on PTPN11/SHP2 phosphatase. 2018

Ruess, Dietrich A / Heynen, Guus J / Ciecielski, Katrin J / Ai, Jiaoyu / Berninger, Alexandra / Kabacaoglu, Derya / Görgülü, Kivanc / Dantes, Zahra / Wörmann, Sonja M / Diakopoulos, Kalliope N / Karpathaki, Angeliki F / Kowalska, Marlena / Kaya-Aksoy, Ezgi / Song, Liang / van der Laan, Eveline A Zeeuw / López-Alberca, María P / Nazaré, Marc / Reichert, Maximilian / Saur, Dieter / Erkan, Mert M / Hopt, Ulrich T / Sainz, Bruno / Birchmeier, Walter / Schmid, Roland M / Lesina, Marina / Algül, Hana. ·Mildred-Scheel-Chair of Tumor Metabolism, Internal Medicine II, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Department of Surgery, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany. · Cancer Research Program, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, Berlin, Germany. · Medicinal Chemistry, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany. · Koç University School of Medicine, Istanbul, Turkey. · Department of Biochemistry, Autónoma University of Madrid, School of Medicine, Instituto de Investigaciones Biomédicas "Alberto Sols", Madrid, Spain. · Mildred-Scheel-Chair of Tumor Metabolism, Internal Medicine II, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. hana.alguel@mri.tum.de. ·Nat Med · Pubmed #29808009.

ABSTRACT: The ubiquitously expressed non-receptor protein tyrosine phosphatase SHP2, encoded by PTPN11, is involved in signal transduction downstream of multiple growth factor, cytokine and integrin receptors

11 Article Stromal heterogeneity in pancreatic cancer and chronic pancreatitis. 2018

Haeberle, Lena / Steiger, Katja / Schlitter, Anna Melissa / Safi, Sami Alexander / Knoefel, Wolfram Trudo / Erkan, Mert / Esposito, Irene. ·Institute of Pathology, Heinrich Heine University and University Hospital of Duesseldorf, Duesseldorf, Germany. · Institute of Pathology, Technische Universitaet Muenchen, Munich, Germany. · Department of Surgery, University Hospital of Duesseldorf, Duesseldorf, Germany. · Department of Surgery, Koc University Hospital, Istanbul, Turkey. · Institute of Pathology, Heinrich Heine University and University Hospital of Duesseldorf, Duesseldorf, Germany. Electronic address: irene.esposito@med.uni-duesseldorf.de. ·Pancreatology · Pubmed #29778400.

ABSTRACT: BACKGROUND/OBJECTIVES: An abundant stromal reaction is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP). The cells mainly responsible for the stromal reaction are activated pancreatic stellate cells (PSCs). Despite their crucial role, PSCs are not well characterized. PSCs share characteristics with the better-known hepatic stellate cells (HSCs). The aim of this study was a detailed analysis of PSCs in PDAC and CP. METHODS: Whole-slide specimens of CP (n = 12) and PDAC (n = 10) were studied by histochemistry and immunohistochemistry. The stroma was evaluated using Movat's pentachrome stain. PSCs were tested by immunohistochemistry for PSC markers (α-SMA, CD34, desmin, NGFR, SPARC and tenascin C) and HSC markers (α-crystallin B, CD56, NGF, NT-3, synaptophysin and TrkC). Alpha-SMA, tenascin C, SPARC and NT-3 staining were verified on tissue micro arrays (TMAs) from a well-characterized cohort of 223 PDAC patients. PSCs isolated from human PDAC and CP tissue samples as well as HSCs were evaluated by immunofluorescence. RESULTS: While the stroma of CP cases was characterized by a collagen-rich fibrosis, PDAC stroma displayed higher mucin content (p = 0.0002). PSCs showed variable expression of tested markers. In PDAC samples, staining of most markers was found around tumor complexes, while CP samples showed a greater variety of localizations. Alpha-SMA staining correlated with collagen-rich fibrosis (p = 0.012), while NT-3 staining correlated with mucin-rich stroma (p = 0.008). A peritumoral staining was confirmed for α-SMA, tenascin C, SPARC and NT-3 in the PDAC TMA cohort (n = 223). In a subgroup of patients with pancreatic head tumors and UICC 2009 IIB (n = 144), α-SMA staining intensity was a prognostic factor for overall survival at uni- and multivariate analysis (p = 0.036 and p = 0.002). CONCLUSIONS: The close similarities between PSCs and HSCs were confirmed. Heterogeneous expression patterns of the tested markers might reflect different levels of activation or differentiation, or even multiple subpopulations of PSCs. Survival analysis suggests an impact of stromal composition on survival.

12 Article Dynamic landscape of pancreatic carcinogenesis reveals early molecular networks of malignancy. 2018

Kong, Bo / Bruns, Philipp / Behler, Nora A / Chang, Ligong / Schlitter, Anna Melissa / Cao, Jing / Gewies, Andreas / Ruland, Jürgen / Fritzsche, Sina / Valkovskaya, Nataliya / Jian, Ziying / Regel, Ivonne / Raulefs, Susanne / Irmler, Martin / Beckers, Johannes / Friess, Helmut / Erkan, Mert / Mueller, Nikola S / Roth, Susanne / Hackert, Thilo / Esposito, Irene / Theis, Fabian J / Kleeff, Jörg / Michalski, Christoph W. ·Department of Surgery, Technische Universität München (TUM), Munich, Germany. · Department of Gastroenterology, Nanjing Drum Tower Hospital, Nanjing University, Nanjing, China. · Institute of Computational Biology, Helmholtz-Zentrum München GmbH, Neuherberg, Germany. · Institute of Pathology, TUM, Munich, Germany. · Institute für Klinische Chemie und Pathobiochemie, TUM, Munich, Germany. · Research Unit Cellular Signal Integration, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, Neuherberg, Germany. · German Cancer Consortium (DKTK) at the partner site Munich and German Cancer Research Center (DKFZ), Heidelberg, Germany. · German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany. · Institute of Pathology, Heinrich-Heine University, Duesseldorf, Germany. · Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, Neuherberg, Germany. · Chair of Experimental Genetics, Technische Universität München, Freising, Germany. · Deutsches Zentrum für Diabetesforschung, Neuherberg, Germany. · Department of Surgery, Koc University, Istanbul, Turkey. · Department of Surgery, University of Heidelberg, Heidelberg, Germany. · Department of Mathematics, TUM, Munich, Germany. · NIHR Pancreas Biomedical Research Unit, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK. ·Gut · Pubmed #27646934.

ABSTRACT: OBJECTIVE: The initial steps of pancreatic regeneration versus carcinogenesis are insufficiently understood. Although a combination of oncogenic Kras and inflammation has been shown to induce malignancy, molecular networks of early carcinogenesis remain poorly defined. DESIGN: We compared early events during inflammation, regeneration and carcinogenesis on histological and transcriptional levels with a high temporal resolution using a well-established mouse model of pancreatitis and of inflammation-accelerated Kras RESULTS: We defined three distinctive phases-termed inflammation, regeneration and refinement-following induction of moderate acute pancreatitis in wild-type mice. These corresponded to different waves of proliferation of mesenchymal, progenitor-like and acinar cells. Pancreas regeneration required a coordinated transition of proliferation between progenitor-like and acinar cells. In mice harbouring an oncogenic Kras mutation and challenged with pancreatitis, there was an extended inflammatory phase and a parallel, continuous proliferation of mesenchymal, progenitor-like and acinar cells. Analysis of high-resolution transcriptional data from wild-type animals revealed that organ regeneration relied on a complex interaction of a gene network that normally governs acinar cell homeostasis, exocrine specification and intercellular signalling. In mice with oncogenic Kras, a specific carcinogenic signature was found, which was preserved in full-blown mouse pancreas cancer. CONCLUSIONS: These data define a transcriptional signature of early pancreatic carcinogenesis and a molecular network driving formation of preneoplastic lesions, which allows for more targeted biomarker development in order to detect cancer earlier in patients with pancreatitis.

13 Article Co-clinical Assessment of Tumor Cellularity in Pancreatic Cancer. 2017

Heid, Irina / Steiger, Katja / Trajkovic-Arsic, Marija / Settles, Marcus / Eßwein, Manuela R / Erkan, Mert / Kleeff, Jörg / Jäger, Carsten / Friess, Helmut / Haller, Bernhard / Steingötter, Andreas / Schmid, Roland M / Schwaiger, Markus / Rummeny, Ernst J / Esposito, Irene / Siveke, Jens T / Braren, Rickmer F. ·Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Germany. · Institute of Pathology, Klinikum rechts der Isar, Technische Universität München, Germany. · 2nd Medical Department, Klinikum rechts der Isar, Technische Universität München, Germany. · German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany. · Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK), partner site Essen, University Hospital Essen, Essen, Germany. · Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Germany. · Institute of Medical Statistics and Epidemiology, Klinikum rechts der Isar, Technische Universität München, Germany. · Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland. · Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Germany. · Institute of Pathology, Universitätsklinikum Düsseldorf, Düsseldorf, Germany. rbraren@tum.de j.siveke@dkfz-heidelberg.de Irene.Esposito@med.uni-duesseldorf.de. · 2nd Medical Department, Klinikum rechts der Isar, Technische Universität München, Germany. rbraren@tum.de j.siveke@dkfz-heidelberg.de Irene.Esposito@med.uni-duesseldorf.de. · Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Germany. rbraren@tum.de j.siveke@dkfz-heidelberg.de Irene.Esposito@med.uni-duesseldorf.de. ·Clin Cancer Res · Pubmed #27663591.

ABSTRACT:

14 Article Activated leukocyte cell adhesion molecule regulates the interaction between pancreatic cancer cells and stellate cells. 2016

Zhang, Wei-Wei / Zhan, Shu-Hui / Geng, Chang-Xin / Sun, Xin / Erkan, Mert / Kleeff, Jörg / Xie, Xiang-Jun. ·Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, Shandong 266071, P.R. China. · Department of Surgery, Koc University School of Medicine, Istanbul 34450, Turkey. · Department of Surgery, Technical University of Munich, D-80333 Munich, Germany. ·Mol Med Rep · Pubmed #27573419.

ABSTRACT: Activated leukocyte cell adhesion molecule (ALCAM/CD166) is a transmembrane glycoprotein that is involved in tumor progression and metastasis. In the present study, the expression and functional role of ALCAM in pancreatic cancer cells and pancreatic stellate cells (PSCs) was investigated. Tissue specimens were obtained from patients with pancreatic ductal adenocarcinoma (n=56) or chronic pancreatitis (CP; n=10), who underwent pancreatic resection, and from normal pancreatic tissue samples (n=10). Immunohistochemistry was used to analyze the localization and expression of ALCAM in pancreatic tissues. Subsequently, reverse transcription‑quantitative polymerase chain reaction and immunoblotting were applied to assess the expression of ALCAM in pancreatic cancer Panc‑1 and T3M4 cells, as well as in PSCs. An enzyme‑linked immunosorbent assay was used to measure ALCAM levels in cell culture medium stimulated by hypoxia, tumor necrosis factor (TNF)‑α and transforming growth factor‑β. Silencing of ALCAM was performed using ALCAM small interfering (si)RNA and immunocytochemistry was used to analyze the inhibition efficiency. An invasion assay and a cell interaction assay were performed to assess the invasive ability and co‑cultured adhesive potential of Panc‑1 and T3M4 cells, as well as PSCs. Histologically, ALCAM expression was generally weak or absent in pancreatic cancer cells, but was markedly upregulated in PSCs in pancreatic cancer tissues. ALCAM was highly expressed in PSCs from CP tissues and PSCs surrounding pancreatic intraepithelial neoplasias, as well as in pancreatic cancer cells. ALCAM mRNA was highly expressed in PSCs, with a low to moderate expression in T3M4 and Panc‑1 cells. Similar to the mRNA expression, immunoblotting demonstrated that ALCAM protein levels were high in PSCs and T3M4 cells, but low in Panc‑1 cells. The expression of TNF‑α increased, while hypoxia decreased the secretion of ALCAM in pancreatic cancer Panc‑1 and T3M4 cells, and also in PSCs. Silencing of ALCAM by siRNA revealed no significant alteration in the invasion of pancreatic cancer cells, however, it inhibited the invasive ability of PSCs, and decreased the interaction between Panc‑1 cells and PSCs. In conclusion, ALCAM is upregulated in PSCs of pancreatic cancer tissues, suggesting a potential role of ALCAM in regulating pancreatic cancer cell‑PSC interactions.

15 Article Pancreatic Premalignant Lesions Secrete Tissue Inhibitor of Metalloproteinases-1, Which Activates Hepatic Stellate Cells Via CD63 Signaling to Create a Premetastatic Niche in the Liver. 2016

Grünwald, Barbara / Harant, Veronika / Schaten, Susanne / Frühschütz, Monika / Spallek, Ria / Höchst, Bastian / Stutzer, Katharina / Berchtold, Sonja / Erkan, Mert / Prokopchuk, Olga / Martignoni, Marc / Esposito, Irene / Heikenwalder, Mathias / Gupta, Aayush / Siveke, Jens / Saftig, Paul / Knolle, Percy / Wohlleber, Dirk / Krüger, Achim. ·Institut für Molekulare Immunologie und Experimentelle Onkologie, Technische Universität München, München, Germany. · Chirurgische Klinik Technische Universität München, München, Germany. · Institut für Pathologie, Klinikum rechts der Isar, Technische Universität München, München, Germany. · Institut für Virologie, Technische Universität München, München, Germany. · II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, München, Germany. · Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany. · Institut für Molekulare Immunologie und Experimentelle Onkologie, Technische Universität München, München, Germany. Electronic address: achim.krueger@tum.de. ·Gastroenterology · Pubmed #27506299.

ABSTRACT: BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) metastasizes to liver at early stages, making this disease highly lethal. Tissue inhibitor of metalloproteinases-1 (TIMP1) creates a metastasis-susceptible environment in the liver. We investigated the role of TIMP1 and its receptor CD63 in metastasis of early-stage pancreatic tumors using mice and human cell lines and tissue samples. METHODS: We obtained liver and plasma samples from patients in Germany with chronic pancreatitis, pancreatic intra-epithelial neoplasia, or PDAC, as well as hepatic stellate cells (HSCs). We performed studies with Ptf1a RESULTS: Chronic pancreatitis, pancreatic intra-epithelial neoplasia, and PDAC tissues from patients expressed higher levels of TIMP1 protein than normal pancreas. The premalignant pancreatic lesions that developed in KPC and CPK mice expressed TIMP1 and secreted it into the circulation. In vitro and in vivo, TIMP1 activated human or mouse HSCs, which required interaction between TIMP1 and CD63 and signaling via phosphatidylinositol 3-kinase, but not TIMP1 protease inhibitor activity. This signaling pathway induced expression of endogenous TIMP1. TIMP1 knockdown in HSCs reduced their activation. Cultured TIMP1-activated human and mouse HSCs began to express stromal-derived factor-1, which induced neutrophil migration, a marker of the premetastatic niche. Mice with pancreatic intra-epithelial neoplasia-derived systemic increases in TIMP1 developed more liver metastases after injections of pancreatic cancer cells than mice without increased levels of TIMP1. This increase in formation of liver metastases from injected pancreatic cancer cells was not observed in TIMP1 or CD63 knockout mice. CONCLUSIONS: Expression of TIMP1 is increased in chronic pancreatitis, pancreatic intra-epithelial neoplasia, and PDAC tissues from patients. TIMP1 signaling via CD63 leads to activation of HSCs, which create an environment in the liver that increases its susceptibility to pancreatic tumor cells. Strategies to block TIMP1 signaling via CD63 might be developed to prevent PDAC metastasis to the liver.

16 Article A subset of metastatic pancreatic ductal adenocarcinomas depends quantitatively on oncogenic Kras/Mek/Erk-induced hyperactive mTOR signalling. 2016

Kong, Bo / Wu, Weiwei / Cheng, Tao / Schlitter, Anna Melissa / Qian, Chengjia / Bruns, Philipp / Jian, Ziying / Jäger, Carsten / Regel, Ivonne / Raulefs, Susanne / Behler, Nora / Irmler, Martin / Beckers, Johannes / Friess, Helmut / Erkan, Mert / Siveke, Jens T / Tannapfel, Andrea / Hahn, Stephan A / Theis, Fabian J / Esposito, Irene / Kleeff, Jörg / Michalski, Christoph W. ·Department of Surgery, Technische Universität München (TUM), Munich, Germany. · Institute of Pathology, TUM, Munich, Germany. · Department of Surgery, Technische Universität München (TUM), Munich, Germany Institute of Computational Biology, Helmholtz-Zentrum München, Munich, Germany. · Institute of Experimental Genetics (IEG), Helmholtz-Zentrum München, Munich, Germany. · Institute of Experimental Genetics (IEG), Helmholtz-Zentrum München, Munich, Germany Technische Universität München, Chair of Experimental Genetics, Freising, Germany Deutsches Zentrum für Diabetesforschung (DZD), Neuherberg, Germany. · Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Department of Gastroenterology, TUM, Munich, Germany. · Institute of Pathology, Ruhr-University Bochum, Bochum, Germany. · Department of Molecular Gastrointestinal Oncology, Ruhr-University Bochum, Bochum, Germany. · Institute of Computational Biology, Helmholtz-Zentrum München, Munich, Germany. · Department of Surgery, University of Heidelberg, Heidelberg, Germany. ·Gut · Pubmed #25601637.

ABSTRACT: OBJECTIVE: Oncogenic Kras-activated robust Mek/Erk signals phosphorylate to the tuberous sclerosis complex (Tsc) and deactivates mammalian target of rapamycin (mTOR) suppression in pancreatic ductal adenocarcinoma (PDAC); however, Mek and mTOR inhibitors alone have demonstrated minimal clinical antitumor activity. DESIGN: We generated transgenic mouse models in which mTOR was hyperactivated either through the Kras/Mek/Erk cascade, by loss of Pten or through Tsc1 haploinsufficiency. Primary cancer cells were isolated from mouse tumours. Oncogenic signalling was assessed in vitro and in vivo, with and without single or multiple targeted molecule inhibition. Transcriptional profiling was used to identify biomarkers predictive of the underlying pathway alterations and of therapeutic response. Results from the preclinical models were confirmed on human material. RESULTS: Reduction of Tsc1 function facilitated activation of Kras/Mek/Erk-mediated mTOR signalling, which promoted the development of metastatic PDACs. Single inhibition of mTOR or Mek elicited strong feedback activation of Erk or Akt, respectively. Only dual inhibition of Mek and PI3K reduced mTOR activity and effectively induced cancer cell apoptosis. Analysis of downstream targets demonstrated that oncogenic activity of the Mek/Erk/Tsc/mTOR axis relied on Aldh1a3 function. Moreover, in clinical PDAC samples, ALDH1A3 specifically labelled an aggressive subtype. CONCLUSIONS: These results advance our understanding of Mek/Erk-driven mTOR activation and its downstream targets in PDAC, and provide a mechanistic rationale for effective therapeutic matching for Aldh1a3-positive PDACs.

17 Article Pancreas-specific activation of mTOR and loss of p53 induce tumors reminiscent of acinar cell carcinoma. 2015

Kong, Bo / Cheng, Tao / Qian, Chengjia / Wu, Weiwei / Steiger, Katja / Cao, Jing / Schlitter, Anna Melissa / Regel, Ivonne / Raulefs, Susanne / Friess, Helmut / Erkan, Mert / Esposito, Irene / Kleeff, Jörg / Michalski, Christoph W. ·Department of Surgery, Technische Universität München (TUM), Munich, Germany. · Institute of Pathology, TUM, Munich, Germany. · Department of Surgery, Koc School of Medicine, Istanbul, Turkey. · Institute of Pathology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany. · Royal Liverpool and Broadgreen University Hospitals, Liverpool, UK. · Department of Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany. cwmichalski@gmail.com. ·Mol Cancer · Pubmed #26683340.

ABSTRACT: BACKGROUND: Pancreatic acinar cell carcinoma (ACC) is a rare tumor entity with an unfavorable prognosis. Recent whole-exome sequencing identified p53 mutations in a subset of human ACC. Activation of the mammalian target of rapamycin (mTOR) pathway is associated with various pancreatic neoplasms. We thus aimed at analyzing whether activation of mTOR with a concomitant loss of p53 may initiate ACC. METHODS: We generated transgenic mouse models in which mTOR was hyperactivated through pancreas-specific, homozygous tuberous sclerosis 1 (Tsc1) deficiency, with or without deletion of p53 (Tsc1 (-/-) and Tsc1 (-/-) ; p53 (-/-) ). Activity of mTOR signaling was investigated using mouse tissues and isolated murine cell lines. Human ACC specimens were used to corroborate the findings from the transgenic mouse models. RESULTS: Hyperactive mTOR signaling in Tsc1 (-/-) mice was not oncogenic but rather induced a near-complete loss of the pancreatic acinar compartment. Acinar cells were lost as a result of apoptosis which was associated with p53 activation. Concomitantly, ductal cells were enriched. Ablation of p53 in Tsc1-deficient mice prevented acinar cell death but promoted formation of acinar cells with severe nuclear abnormalities. One out of seven Tsc1 (-/-) ; p53 (-/-) animals developed pancreatic tumors showing a distinctive tumor morphology, reminiscent of human ACC. Hyperactive mTOR signaling was also detected in a subset of human ACC. CONCLUSION: Hyperactive mTOR signaling combined with loss of p53 in mice induces tumors similar to human ACC.

18 Article Hypoxia-induced endoplasmic reticulum stress characterizes a necrotic phenotype of pancreatic cancer. 2015

Kong, Bo / Cheng, Tao / Wu, Weiwei / Regel, Ivonne / Raulefs, Susanne / Friess, Helmut / Erkan, Mert / Esposito, Irene / Kleeff, Jörg / Michalski, Christoph W. ·Department of Surgery, Technische Universität München (TUM), Munich, Germany. · Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Institute of Pathology, Medical University Innsbruck, Innsbruck, Austria. · Department of Surgery, University of Heidelberg, Heidelberg, Germany. ·Oncotarget · Pubmed #26452217.

ABSTRACT: Stromal fibrosis and tissue necrosis are major histological sequelae of hypoxia. The hypoxia-to-fibrosis sequence is well-documented in pancreatic ductal adenocarcinoma (PDAC). However, hypoxic and necrotic PDAC phenotypes are insufficiently characterized. Recently, reduction of tuberous sclerosis expression in mice together with oncogenic Kras demonstrated a rapidly metastasizing phenotype with histologically eccentric necrosis, transitional hypoxia and devascularisation. We established cell lines from these tumors and transplanted them orthotopically into wild-type mice to test their abilities to recapitulate the histological features of the primary lesions. Notably, the necrotic phenotype was reproduced by only a subset of cell lines while others gave rise to dedifferentiated tumors with significantly reduced necrosis. In vitro analysis of the necrotic tumor-inducing cell lines revealed that these cells released a significant amount of vascular endothelial growth factor A (Vegfa). However, its release was not further increased under hypoxic conditions. Defective hypoxia-induced Vegfa secretion was not due to impaired Vegfa transcription or hypoxia-inducible factor 1-alpha activation, but rather a result of hypoxia-induced endoplasmic reticulum (ER) stress. We thus identified hypoxia-induced ER stress as an important pathway in PDACs with tissue necrosis and rapid metastasis.

19 Article Hippo pathway elements Co-localize with Occludin: A possible sensor system in pancreatic epithelial cells. 2015

Cravo, Ana Santos / Carter, Edward / Erkan, Mert / Harvey, Emma / Furutani-Seiki, Makoto / Mrsny, Randall. ·Department of Pharmacy and Pharmacology; University of Bath ; Bath, UK. · Department of Surgery; Koc University School of Medicine ; Istanbul, Turkey. · Department of Biology and Biochemistry; University of Bath ; Bath, UK. ·Tissue Barriers · Pubmed #26451343.

ABSTRACT: External adherens junction-based cell-cell contacts involving E-cadherin interactions function to sense planar cell status and modulate epithelial cell proliferation through Hippo (Hpo) and non-canonical Wnt pathways signaling. We hypothesized these regulatory processes should also be sensitive to a similar cell-cell contact sensor associated with apical-basal polarity events at epithelial surfaces. We used 2 human pancreatic cancer cell lines to explore this hypothesis: one with the capacity to form functional tight junction structures and polarize (HPAFII) and one lacking this capacity (AsPc1). Occludin (Ocln), a tetraspanning protein associated with TJ structures and capable of establishing external cell-cell contacts, was observed to partially co-localize with Hpo elements YAP (c-yes associated protein) and TEAD (TEA-dependent), which function to drive a proliferative transcription program. Treatment with dobutamine, known to affect YAP, was shown to suppress proliferation in an Ocln-dependent manner. Blockade of protein kinase C-zeta (PKC-ζ) diminished transepithelial electrical resistance (TER) of HPAFII monolayers that was not corrected by dobutamine treatment while the loss of TER resulting from inhibition of ROCK1 could be partially recovered. Examination of normal and cancerous human pancreatic biopsies showed that the cellular localization of Ocln, c-Yes, YAP, and TEAD were similar to HPAFII for normal cells and AsPc1 for cancerous cells. Together, these results suggest a link between Hpo and signals emanating from cell-cell contacts involving Ocln that may regulate pancreatic cell proliferation through the coordination of planar cell polarity with apical-basal polarity events.

20 Article Combined inhibition of BET family proteins and histone deacetylases as a potential epigenetics-based therapy for pancreatic ductal adenocarcinoma. 2015

Mazur, Pawel K / Herner, Alexander / Mello, Stephano S / Wirth, Matthias / Hausmann, Simone / Sánchez-Rivera, Francisco J / Lofgren, Shane M / Kuschma, Timo / Hahn, Stephan A / Vangala, Deepak / Trajkovic-Arsic, Marija / Gupta, Aayush / Heid, Irina / Noël, Peter B / Braren, Rickmer / Erkan, Mert / Kleeff, Jörg / Sipos, Bence / Sayles, Leanne C / Heikenwalder, Mathias / Heßmann, Elisabeth / Ellenrieder, Volker / Esposito, Irene / Jacks, Tyler / Bradner, James E / Khatri, Purvesh / Sweet-Cordero, E Alejandro / Attardi, Laura D / Schmid, Roland M / Schneider, Guenter / Sage, Julien / Siveke, Jens T. ·Department of Pediatrics, Stanford University School of Medicine, California, USA. · Department of Genetics, Stanford University School of Medicine, California, USA. · Second Department of Internal Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Department of Radiation Oncology, Stanford University School of Medicine, California, USA. · Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · David H. Koch Institute for Integrative Cancer Research, Department of Biology, and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. · Department of Medicine, Stanford University School of Medicine, California, USA. · Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, California, USA. · Department of Molecular Gastrointestinal Oncology, Ruhr-University Bochum, Bochum, Germany. · Ruhr-University Bochum, Medical Clinic, Knappschaftskrankenhaus, Bochum, Germany. · Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Institute of Pathology, University of Tübingen, Tübingen, Germany. · Institute of Virology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Division of Chronic Inflammation and Cancer, German Cancer Research center (DKFZ) Heidelberg, Germany. · Department of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany. · Institute of Pathology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA. · German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany. ·Nat Med · Pubmed #26390243.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers and shows resistance to any therapeutic strategy used. Here we tested small-molecule inhibitors targeting chromatin regulators as possible therapeutic agents in PDAC. We show that JQ1, an inhibitor of the bromodomain and extraterminal (BET) family of proteins, suppresses PDAC development in mice by inhibiting both MYC activity and inflammatory signals. The histone deacetylase (HDAC) inhibitor SAHA synergizes with JQ1 to augment cell death and more potently suppress advanced PDAC. Finally, using a CRISPR-Cas9-based method for gene editing directly in the mouse adult pancreas, we show that de-repression of p57 (also known as KIP2 or CDKN1C) upon combined BET and HDAC inhibition is required for the induction of combination therapy-induced cell death in PDAC. SAHA is approved for human use, and molecules similar to JQ1 are being tested in clinical trials. Thus, these studies identify a promising epigenetic-based therapeutic strategy that may be rapidly implemented in fatal human tumors.

21 Article Resectability After First-Line FOLFIRINOX in Initially Unresectable Locally Advanced Pancreatic Cancer: A Single-Center Experience. 2015

Nitsche, Ulrich / Wenzel, Patrick / Siveke, Jens T / Braren, Rickmer / Holzapfel, Konstantin / Schlitter, Anna M / Stöß, Christian / Kong, Bo / Esposito, Irene / Erkan, Mert / Michalski, Christoph W / Friess, Helmut / Kleeff, Jörg. ·Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Department of Internal Medicine II, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. · Institute of Pathology, Technische Universität München, Munich, Germany. · Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany. · Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Department of Surgery, University of Heidelberg, Heidelberg, Germany. · Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. kleeff@tum.de. ·Ann Surg Oncol · Pubmed #26350368.

ABSTRACT: BACKGROUND: FOLFIRINOX is an active but relatively toxic chemotherapeutic regimen for patients with metastatic pancreatic ductal adenocarcinoma (PDAC). The increased frequency of responding tumors shift interest to neoadjuvant approaches. We report our institutional experience with FOLFIRINOX for therapy-naïve patients with locally advanced and initially unresectable PDAC. METHODS: All patients with unresectable locally advanced PDAC who underwent treatment with FOLFIRINOX at a single center between 2011 and 2014 were identified and evaluated retrospectively regarding chemotherapy response, toxicity, conversion to resectability, and survival. Resectability, response to chemotherapy, and postoperative complications were reported according to NCCN-guidelines, RECIST-criteria, and Clavien-Dindo-classification, respectively. RESULTS: Overall, 14 patients received FOLFIRINOX as first-line therapy for locally advanced and unresectable PDAC. Fifty-seven percent of the patients had severe tumor-related comorbidities at the time of diagnosis, and in 86 %, dose reduction due to toxicity was necessary during a median of seven cycles. Nevertheless, only one patient had progressive disease during FOLFIRINOX, whereas the others experienced stable disease (n = 6) or partial remission (n = 6; no restaging in one patient). Oncological tumor resection was possible in 4 patients (29 % of all patients) with no postoperative mortality and only one grade 2 surgical complication. After a median follow-up of 10 months, 4 of the 14 patients were still in remission, 5 were alive with stable disease under ongoing systemic chemotherapy, and 5 died tumor-related. CONCLUSIONS: FOLFIRINOX is a powerful first-line regimen that leads to resectability in a substantial portion of patients with initially unresectable pancreatic cancer.

22 Article Outcomes of resections for pancreatic adenocarcinoma with suspected venous involvement: a single center experience. 2015

Michalski, Christoph W / Kong, Bo / Jäger, Carsten / Kloe, Silke / Beier, Barbara / Braren, Rickmer / Esposito, Irene / Erkan, Mert / Friess, Helmut / Kleeff, Jorg. ·Department of Surgery, Technische Universität München, Ismaningerstrasse 22, 81675, Munich, Germany. · Current address: Department of Surgery, University of Heidelberg, Heidelberg, Germany. · Institute of Radiology, Technische Universität München, Munich, Germany. · Institute of Pathology, Technische Universität München, Munich, Germany. · Current address: Institute of Pathology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany. · Current address: Department of Surgery, Koc University School of Medicine, Istanbul, Turkey. · Department of Surgery, Technische Universität München, Ismaningerstrasse 22, 81675, Munich, Germany. kleeff@tum.de. ·BMC Surg · Pubmed #26296752.

ABSTRACT: BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) patients frequently present with borderline resectable disease, which can be due to invasion of the portal/superior mesenteric vein (PV/SMV). Here, we analyzed this group of patients, with emphasis on short and long-term outcomes. METHODS: 156 patients who underwent a resection for PDAC were included in the analysis and sub-stratified into a cohort of patients with PV/SMV resection (n = 54) versus those with standard surgeries (n = 102). RESULTS: While venous resections could be performed safely, there was a trend towards shorter median survival in the PV/SMV resection group (22.7 vs. 15.8 months, p = 0.157). These tumors were significantly larger (3.5 vs. 4.3 cm; p = 0.026) and margin-positivity was more frequent (30.4% vs. 44.4%, p = 0.046). CONCLUSION: Venous resection was associated with a higher rate of margin positivity and a trend towards shorter survival. However, compared to non-surgical treatment, resection offers the best chance for long term survival.

23 Article Kif20a inhibition reduces migration and invasion of pancreatic cancer cells. 2015

Stangel, Daniela / Erkan, Mert / Buchholz, Malte / Gress, Thomas / Michalski, Christoph / Raulefs, Susanne / Friess, Helmut / Kleeff, Jörg. ·Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany. · Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; Department of Surgery, Koc School of Medicine, Istanbul, Turkey. Electronic address: m.mert.erkan@googlemail.com. · Department of Gastroenterology and Endocrinology, University Hospital, Philipps-University, Marburg, Germany. · Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; Department of Surgery, University of Heidelberg, Heidelberg, Germany. ·J Surg Res · Pubmed #25953216.

ABSTRACT: BACKGROUND: The Translational Genome Research Network in Pancreatic Cancer performed a meta-analysis of publicly available various high-throughput gene analysis panels to identify drugable targets. There, the most differentially expressed gene between normal and cancerous pancreas was Kif20a. The aim of the study was to verify this expression pattern and further characterize Kif20a in pancreatic cancer. MATERIALS AND METHODS: Detailed expression analyses were carried out in pancreatic tissues and in a wide panel of pancreatic cells including ductal adenocarcinoma (PDAC) and neuroendocrine-cancer cell lines as well as immortalized human pancreatic ductal epithelial and primary stellate cells using quantitative real-time polymerase chain reaction, immunohistochemistry, immunofluorescence, and immunoblot analyses. Effects on proliferation, apoptosis, and cell cycle were assessed by MTT assays, caspase-cleavage assays, and fluorescence-activated cell sorting analysis after Kif20a silencing. Cell motility was assessed by migration and invasion assays as well as time-lapse microscopy. RESULTS: Mean Kif20a messenger RNA expression was 18.4-fold upregulated in PDAC tissues compared with that in the normal pancreas. In line, neuroendocrine-cancer cell lines display a 1.6-fold increase and ductal adenocarcinoma cell lines a 11-fold increase of Kif20a messenger RNA (P = 0.009) in comparison with primary stellate cells. A 7.3-fold overexpression was also found in immortalized pancreatic ductal epithelial cells. Kif20a silencing with small interfering RNA molecules resulted in an inhibition of proliferation, motility, and invasion of pancreatic cancer cell lines. CONCLUSIONS: Targeting Kif20a reduces proliferation, migration, and invasion of pancreatic cancer cells. Together with its significant overexpression in PDAC, this makes it a potential target for diagnostic and interventional purposes.

24 Article Microenvironmental hCAP-18/LL-37 promotes pancreatic ductal adenocarcinoma by activating its cancer stem cell compartment. 2015

Sainz, Bruno / Alcala, Sonia / Garcia, Elena / Sanchez-Ripoll, Yolanda / Azevedo, Maria M / Cioffi, Michele / Tatari, Marianthi / Miranda-Lorenzo, Irene / Hidalgo, Manuel / Gomez-Lopez, Gonzalo / Cañamero, Marta / Erkan, Mert / Kleeff, Jörg / García-Silva, Susana / Sancho, Patricia / Hermann, Patrick C / Heeschen, Christopher. ·Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain Department of Preventive Medicine, Public Health and Microbiology, Universidad Autónoma de Madrid, Madrid, Spain. · Molecular Diagnostics Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain Pathology Department, Hospital Universitario Fundacion Alcorcon, Madrid, Spain. · Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. · Gastrointestinal Cancer Clinical Research Unit, Clinical Research Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. · Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. · Histopathology Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. · Department of Surgery, Klinikum rechts der Isar, Technical University, Munich, Germany Koc University School of Medicine, Istanbul, Turkey. · Department of Surgery, Klinikum rechts der Isar, Technical University, Munich, Germany. · Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain Deptartment of Internal Medicine I, Ulm University, Ulm, Germany. · Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain Centre for Stem Cells in Cancer & Ageing, Barts Cancer Institute, Queen Mary University of London, London, UK. ·Gut · Pubmed #25841238.

ABSTRACT: OBJECTIVES: The tumour stroma/microenvironment not only provides structural support for tumour development, but more importantly it provides cues to cancer stem cells (CSCs) that regulate their self-renewal and metastatic potential. This is certainly true for pancreatic ductal adenocarcinomas (PDAC), where tumour-associated fibroblasts, pancreatic stellate cells and immune cells create an abundant paracrine niche for CSCs via microenvironment-secreted factors. Thus understanding the role that tumour stroma cells play in PDAC development and CSC biology is of utmost importance. DESIGN: Microarray analyses, tumour microarray immunohistochemical assays, in vitro co-culture experiments, recombinant protein treatment approaches and in vivo intervention studies were performed to understand the role that the immunomodulatory cationic antimicrobial peptide 18/LL-37 (hCAP-18/LL-37) plays in PDAC biology. RESULTS: We found that hCAP-18/LL-37 was strongly expressed in the stroma of advanced primary and secondary PDAC tumours and is secreted by immune cells of the stroma (eg, tumour-associated macrophages) in response to tumour growth factor-β1 and particularly CSC-secreted Nodal/ActivinA. Treatment of pancreatic CSCs with recombinant LL-37 increased pluripotency-associated gene expression, self-renewal, invasion and tumourigenicity via formyl peptide receptor 2 (FPR2)- and P2X purinoceptor 7 receptor (P2X7R)-dependent mechanisms, which could be reversed by inhibiting these receptors. Importantly, in a genetically engineered mouse model of K-Ras-driven pancreatic tumourigenesis, we also showed that tumour formation was inhibited by either reconstituting these mice with bone marrow from cathelicidin-related antimicrobial peptide (ie, murine homologue of hCAP-18/LL-37) knockout mice or by pharmacologically inhibiting FPR2 and P2X7R. CONCLUSIONS: Thus, hCAP-18/LL-37 represents a previously unrecognised PDAC microenvironment factor that plays a critical role in pancreatic CSC-mediated tumourigenesis.

25 Article Inhibition of CD47 Effectively Targets Pancreatic Cancer Stem Cells via Dual Mechanisms. 2015

Cioffi, Michele / Trabulo, Sara / Hidalgo, Manuel / Costello, Eithne / Greenhalf, William / Erkan, Mert / Kleeff, Joerg / Sainz, Bruno / Heeschen, Christopher. ·Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. · Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centre for Stem Cells in Cancer and Ageing, Barts Cancer Institute, A CR-UK Centre of Excellence, Queen Mary University of London, United Kingdom. · Gastrointestinal Cancer Clinical Research Unit, Clinical Research Programme, CNIO, Madrid, Spain. · Liverpool Cancer Research UK Centre, University of Liverpool, Liverpool, United Kingdom. · Department of Surgery, Technical University Munich, Munich, Germany. Koc University School of Medicine, Instanbul, Turkey. · Department of Surgery, Technical University Munich, Munich, Germany. · Stem Cells and Cancer Group, Molecular Pathology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centre for Stem Cells in Cancer and Ageing, Barts Cancer Institute, A CR-UK Centre of Excellence, Queen Mary University of London, United Kingdom. c.heeschen@qmul.ac.uk. ·Clin Cancer Res · Pubmed #25717063.

ABSTRACT: PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is a cancer of the exocrine pancreas with unmet medical need and is strongly promoted by tumor-associated macrophages (TAM). The presence of TAMs is associated with poor clinical outcome, and their overall role, therefore, appears to be protumorigenic. The "don't eat me" signal CD47 on cancer cells communicates to the signal regulatory protein-α on macrophages and prevents their phagocytosis. Thus, inhibition of CD47 may offer a new opportunity to turn TAMs against PDAC cells, including cancer stem cells (CSC), as the exclusively tumorigenic population. EXPERIMENTAL DESIGN: We studied in vitro and in vivo the effects of CD47 inhibition on CSCs using a large set of primary pancreatic cancer (stem) cells as well as xenografts of primary human PDAC tissue. RESULTS: CD47 was highly expressed on CSCs, but not on other nonmalignant cells in the pancreas. Targeting CD47 efficiently enhanced phagocytosis of a representative set of primary human pancreatic cancer (stem) cells and, even more intriguingly, also directly induced their apoptosis in the absence of macrophages during long-term inhibition of CD47. In patient-derived xenograft models, CD47 targeting alone did not result in relevant slowing of tumor growth, but the addition of gemcitabine or Abraxane resulted in sustained tumor regression and prevention of disease relapse long after discontinuation of treatment. CONCLUSIONS: These data are consistent with efficient in vivo targeting of CSCs, and strongly suggest that CD47 inhibition could be a novel adjuvant treatment strategy for PDAC independent of underlying and highly variable driver mutations.

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