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Pancreatic Neoplasms: HELP
Articles by Hendrik Ungefroren
Based on 15 articles published since 2010
(Why 15 articles?)
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Between 2010 and 2020, Hendrik Ungefroren wrote the following 15 articles about Pancreatic Neoplasms.
 
+ Citations + Abstracts
1 Review The role of small GTPases of the Rho/Rac family in TGF-β-induced EMT and cell motility in cancer. 2018

Ungefroren, Hendrik / Witte, David / Lehnert, Hendrik. ·First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, and University of Lübeck, Lübeck, Germany. · Department of General and Thoracic Surgery, UKSH, Campus Kiel, Kiel, Germany. ·Dev Dyn · Pubmed #28390160.

ABSTRACT: This article focuses on the role of Rho family GTPases, particularly Rac1 and Rac1b in TGF-β-induced epithelial-mesenchymal transition (EMT) and EMT-associated responses such as cell migration, invasion, and metastasis in cancer. EMT is considered a prerequisite for cells to adopt a motile and invasive phenotype and eventually become metastatic. A major regulator of EMT and metastasis in cancer is TGF-β, and its specific functions on tumor cells are mediated beside Smad proteins and mitogen-activated protein kinases (MAPKs) by small GTPases of the Rho/Rac1 family. Available data point to extensive signaling crosstalk between TGF-β and various Rho GTPases, and in particular a synergistic role of Rho and Rac1 during EMT and cell motility in normal and neoplastic epithelial cells. In contrast, the Rac1-related isoform, Rac1b, emerges as an endogenous inhibitor of Rac1 in TGF-β signaling, at least in pancreatic carcinoma cells. Given the tumor-promoting role of TGF-β in late-stage carcinomas and the intimate crosstalk of Rho/Rac1/Rac1b and TGF-β signaling in various tumor cell responses, targeting specific Rho GTPases may allow for selective interference with prooncogenic TGF-β responses to aid in anticancer treatments. Developmental Dynamics 247:451-461, 2018. © 2017 Wiley Periodicals, Inc.

2 Review The role of TGF-β and its crosstalk with RAC1/RAC1b signaling in breast and pancreas carcinoma. 2017

Melzer, Catharina / Hass, Ralf / von der Ohe, Juliane / Lehnert, Hendrik / Ungefroren, Hendrik. ·Biochemistry and Tumor Biology Lab, Department of Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany. · Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. · First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. · Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. hendrik.ungefroren@uksh.de. · First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. hendrik.ungefroren@uksh.de. · Department of General and Thoracic Surgery, UKSH, Campus Kiel, Kiel, Germany. hendrik.ungefroren@uksh.de. ·Cell Commun Signal · Pubmed #28499439.

ABSTRACT: This article focusses on the role of TGF-β and its signaling crosstalk with the RHO family GTPases RAC1 and RAC1b in the progression of breast and pancreatic carcinoma. The aggressive nature of these tumor types is mainly due to metastatic dissemination. Metastasis is facilitated by desmoplasia, a peculiar tumor microenvironment and the ability of the tumor cells to undergo epithelial-mesenchymal transition (EMT) and to adopt a motile and invasive phenotype. These processes are controlled entirely or in part by TGF-β and the small RHO GTPase RAC1 with both proteins acting as tumor promoters in late-stage cancers. Data from our and other studies point to signaling crosstalk between TGF-β and RAC1 and the related isoform, RAC1b, in pancreatic and mammary carcinoma cells. Based on the exciting observation that RAC1b functions as an endogenous inhibitor of RAC1, we propose a model on how the relative abundance or activity of RAC1 and RAC1b in the tumor cells may determine their responses to TGF-β and, ultimately, the metastatic capacity of the tumor.

3 Review Inhibition of TGF-β Signaling in Tumor Cells by Small Molecule Src Family Kinase Inhibitors. 2017

Bartscht, Tobias / Rosien, Benjamin / Rades, Dirk / Kaufmann, Roland / Biersack, Harald / Lehnerta, Hendrik / Ungefroren, Hendrik. ·First Department of Medicine, UKSH, Campus Lubeck, D-23538 Lubeck. Germany. · Department of Radiation Oncology, UKSH, Campus Lubeck, D-23538 Lubeck. Germany. · Department of General, Visceral and Vascular Surgery, Jena University Hospital, D-07747 Jena. Germany. ·Anticancer Agents Med Chem · Pubmed #28044939.

ABSTRACT: In a series of studies carried out over the last couple of years in various cell types, it was observed that the experimentally used Src family kinase inhibitors PP1 and PP2 and the clinically used Src/Abl inhibitors AZM475271 and dasatinib are potent inhibitors of TGF-β mediated cellular responses such as Smad and p38 mitogen-activated protein kinase phosphorylation, Smad-dependent transcriptional activation, growth inhibition, epithelial-mesenchymal transition (EMT), and cell motility. While for PP1/PP2 it was demonstrated that these agents directly inhibit the kinase activity of the TGF-β type I receptor activin receptor-like kinase 5, the mechanism of the anti-TGF-β effect of AZM475271 and dasatinib is less clear. In contrast, the anti-TGF-β effect of yet another Src/Abl inhibitor, bosutinib, is more variable with respect to the type of the TGF-β response and the cell type affected, and lacks a clear dose-dependency. In the light of their strong anti-activin receptor-like kinase 5 kinase effect, PP1 and PP2 should not be used when studying the role of c-Src as downstream mediators in TGF-β/activin receptor-like kinase 5 signaling. On the other hand, based upon in vitro findings, it is conceivable that part of the therapeutic effects of AZM475271 and dasatinib seen in preclinical and clinical studies with solid tumors was caused by inhibition of prometastatic TGF-β rather than Src signaling. If AZM475271 and dasatinib can indeed act as dual Src / TGF-β inhibitors in vivo, this may be beneficial for prevention of metastatic disease in more advanced tumor stages.

4 Article Diabetes as risk factor for pancreatic cancer: Hyperglycemia promotes epithelial-mesenchymal-transition and stem cell properties in pancreatic ductal epithelial cells. 2018

Rahn, Sascha / Zimmermann, Vivien / Viol, Fabrice / Knaack, Hendrike / Stemmer, Kerstin / Peters, Lena / Lenk, Lennart / Ungefroren, Hendrik / Saur, Dieter / Schäfer, Heiner / Helm, Ole / Sebens, Susanne. ·Institute for Experimental Cancer Research, Christian-Albrechts-University Kiel (CAU) and University Medical Center Schleswig-Holstein (UKSH) Campus Kiel, Kiel, Germany. · Department of Medicine I, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. · Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany. · Department of General Surgery and Thoracic Surgery, UKSH Campus Kiel, Germany; First Department of Medicine, UKSH Campus Lübeck, Lübeck, Germany. · II. Medizinische Klinik und Poliklinik, Klinikum Rechts der Isar, Technical University Munich, Munich, Germany. · Institute for Experimental Cancer Research, Christian-Albrechts-University Kiel (CAU) and University Medical Center Schleswig-Holstein (UKSH) Campus Kiel, Kiel, Germany. Electronic address: susanne.sebens@email.uni-kiel.de. ·Cancer Lett · Pubmed #29222037.

ABSTRACT: Type 2 diabetes mellitus (T2DM) is associated with hyperglycemia and a risk to develop pancreatic ductal adenocarcinoma (PDAC), one of the most fatal malignancies. Cancer stem cells (CSC) are essential for initiation and maintenance of tumors, and acquisition of CSC-features is linked to epithelial-mesenchymal-transition (EMT). The present study investigated whether hyperglycemia promotes EMT and CSC-features in premalignant and malignant pancreatic ductal epithelial cells (PDEC). Under normoglycemia (5 mM d-glucose), Panc1 PDAC cells but not premalignant H6c7-kras cells exhibited a mesenchymal phenotype along with pronounced colony formation. While hyperglycemia (25 mM d-glucose) did not impact the mesenchymal phenotype of Panc1 cells, CSC-properties were aggravated exemplified by increased Nanog expression and Nanog-dependent formation of holo- and meroclones. In H6c7-kras cells, high glucose increased secretion of Transforming-Growth-Factor-beta1 (TGF-β1) as well as TGF-β1 signaling, and in a TGF-β1-dependent manner reduced E-cadherin expression, increased Nestin expression and number of meroclones. Finally, reduced E-cadherin expression was detected in pancreatic ducts of hyperglycemic but not normoglycemic mice. These data suggest that hyperglycemia promotes the acquisition of mesenchymal and CSC-properties in PDEC by activating TGF-β signaling and might explain how T2DM facilitates pancreatic tumorigenesis.

5 Article Negative regulation of TGF-β1-induced MKK6-p38 and MEK-ERK signalling and epithelial-mesenchymal transition by Rac1b. 2017

Witte, David / Otterbein, Hannah / Förster, Maria / Giehl, Klaudia / Zeiser, Robert / Lehnert, Hendrik / Ungefroren, Hendrik. ·First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, and University of Lübeck, 23538, Lübeck, Germany. · Signal Transduction of Cellular Motility, Internal Medicine V, Justus-Liebig-University Giessen, 35392, Giessen, Germany. · Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University, 79106, Freiburg i.Br., Germany. · First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, and University of Lübeck, 23538, Lübeck, Germany. hendrik.ungefroren@uksh.de. · Department of General and Thoracic Surgery, UKSH, Campus Kiel, 24105, Kiel, Germany. hendrik.ungefroren@uksh.de. ·Sci Rep · Pubmed #29229918.

ABSTRACT: Prompted by earlier findings that the Rac1-related isoform Rac1b inhibits transforming growth factor (TGF)-β1-induced canonical Smad signalling, we studied here whether Rac1b also impacts TGF-β1-dependent non-Smad signalling such as the MKK6-p38 and MEK-ERK mitogen-activated protein kinase (MAPK) pathways and epithelial-mesenchymal transition (EMT). Transient depletion of Rac1b protein in pancreatic cancer cells by RNA interference increased the extent and duration of TGF-β1-induced phosphorylation of p38 MAPK in a Smad4-independent manner. Rac1b depletion also strongly increased basal ERK activation - independent of the kinase function of the TGF-β type I receptor ALK5 - and sensitised cells towards further upregulation of phospho-ERK levels by TGF-β1, while ectopic overexpression of Rac1b had the reverse effect. Rac1b depletion increased an EMT phenotype as evidenced by cell morphology, gene expression of EMT markers, cell migration and growth inhibition. Inhibition of MKK6-p38 or MEK-ERK signalling partially relieved the Rac1b depletion-dependent increase in TGF-β1-induced gene expression and cell migration. Rac1b depletion also enhanced TGF-β1 autoinduction of crucial TGF-β pathway components and decreased that of TGF-β pathway inhibitors. Our results show that Rac1b antagonises TGF-β1-dependent EMT by inhibiting MKK6-p38 and MEK-ERK signalling and by controlling gene expression in a way that favors attenuation of TGF-β signalling.

6 Article TGF-β1-induced cell migration in pancreatic carcinoma cells is RAC1 and NOX4-dependent and requires RAC1 and NOX4-dependent activation of p38 MAPK. 2017

Witte, David / Bartscht, Tobias / Kaufmann, Roland / Pries, Ralph / Settmacher, Utz / Lehnert, Hendrik / Ungefroren, Hendrik. ·First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck and University of Lübeck, D-23538 Lübeck, Germany. · Department of General, Visceral and Vascular Surgery, Jena University Hospital, D-07747 Jena, Germany. · Department of Otorhinolaryngology, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany. ·Oncol Rep · Pubmed #29039574.

ABSTRACT: Transforming growth factor (TGF)-β promotes epithelial-mesenchymal transition and cell invasion of cancer cells in part through the small GTPase RAC1. Since RAC1 can signal through reactive oxygen species (ROS), we probed the role of the ROS-producing NADPH oxidase (NOX) and p38 mitogen-activated protein kinase (MAPK) in mediating TGF-β1/RAC1-driven random cell migration (chemokinesis). Although the NOX isoforms NOX2, 4, 5, 6, and RAC1 were readily detectable by RT-PCR in pancreatic ductal adenocarcinoma (PDAC)-derived Panc1 and Colo357 cells, only NOX4 and RAC1 were expressed at higher levels comparable to those in peripheral blood monocytes. TGF-β1 treatment resulted in upregulation of NOX4 (and NOX2) and rapid intracellular production of ROS. To analyze whether RAC1 functions through NOX and ROS to promote cell motility, we performed real-time cell migration assays with xCELLigence® technology in the presence of the ROS scavenger N-acetyl-L-cysteine (NAC) and various NOX inhibitors. NAC, the NOX4 inhibitor diphenylene iodonium or small interfering RNA (siRNA) to NOX4, and the NOX2 inhibitor apocynin all suppressed TGF-β1-induced chemokinesis of Panc1 and Colo357 cells as did various inhibitors of RAC1 used as control. In addition, we showed that blocking NOX4 or RAC1 function abrogated phosphorylation of p38 MAPK signaling by TGF-β1 and that inhibition of p38 MAPK reduced TGF-β1-induced random cell migration, while ectopic expression of a kinase-active version of the p38 activating kinase MKK6 was able to partially rescue the decline in migration after RAC1 inhibition. Our data suggest that TGF-β1-induced chemokinesis in PDAC cells is mediated through a RAC1/NOX4/ROS/p38 MAPK cascade.

7 Article TGF-β Signal Transduction in Pancreatic Carcinoma Cells is Sensitive to Inhibition by the Src Tyrosine Kinase Inhibitor AZM475271. 2017

Bartscht, Tobias / Rosien, Benjamin / Rades, Dirk / Kaufmann, Roland / Biersack, Harald / Lehnert, Hendrik / Ungefroren, Hendrik. ·First Department of Medicine, UKSH, Campus Lübeck, 23538 Lubeck. Germany. · Department of Radiation Oncology, UKSH, Campus Lubeck, D-23538 Lubeck. Germany. · Department of General, Visceral and Vascular Surgery, Jena University Hospital, D- 07747 Jena. Germany. · First Department of Medicine, UKSH, Campus Lubeck, 23538 Lubeck,. Germany. · First Department of Medicine, University of Lubeck, 23538 Lubeck. Germany. ·Anticancer Agents Med Chem · Pubmed #27671303.

ABSTRACT: BACKGROUND: Earlier results from our group have shown that in pancreatic ductal adenocarcinoma (PDAC)-derived cells transforming growth factor (TGF)-β1-dependent epithelial-mesenchymal transition (EMT) and cell motility was inhibited by the Src inhibitors PP2 and PP1 both of which targeted the TGF-β receptors for inhibition. OBJECTIVE: In this study we evaluated the impact of another Src inhibitor, AZM475271, on various TGF-β responses in PDAC cells. METHOD: The effect of AZM475271 on TGF-β1-induced random cell migration (chemokinesis), the expression of EMT and migration/invasion-associated genes, TGF-β-induced luciferase activity, and C-terminal phosphorylation of Smad2 and Smad3 was measured in the PDAC-derived Panc-1 and Colo357 cell lines using real-time cell migration assays, quantitative real-time PCR, luciferase reporter gene assays and phosphoimmunoblotting, respectively. RESULTS: AZM475271 effectively blocked TGF-β1-induced chemokinesis of Panc-1 cells in a dose-dependent fashion and inhibited the high chemokinetic activity of Panc-1 cells with ectopic expression of a constitutively active ALK5T204D mutant. AZM475271 but not another Src inhibitor, SU6656, partially relieved the suppressive effect of TGF-β1 on E-cadherin and inhibited TGF-β1-induced upregulation of the MMP2, MMP9, N-cadherin and vimentin genes, activity of a TGF-β1-dependent reporter gene, and activation of Smad2 and Smad3. CONCLUSION: Our data suggest that AZM475271 cross-inhibits tumor-promoting TGF-β signaling and may thus function as an inhibitor of both TGF-β and Src in both experimental and clinical therapies against metastatic dissemination in late-stage PDAC.

8 Article Negative control of TRAIL-R1 signaling by transforming growth factor β1 in pancreatic tumor cells involves Smad-dependent down regulation of TRAIL-R1. 2016

Radke, David I / Ungefroren, Hendrik / Helm, Ole / Voigt, Susann / Alp, Gökhan / Braun, Hendrik / Hübner, Sebastian / Dilchert, Janine / Sebens, Susanne / Adam, Dieter / Kalthoff, Holger / Trauzold, Anna. ·Institute for Experimental Cancer Research, University of Kiel, D-24105 Kiel, Germany. · First Department of Medicine, UKSH and University of Lübeck, D-23538 Lübeck, Germany. · Institute of Immunology, University of Kiel, D-24105 Kiel, Germany. · Institute for Experimental Cancer Research, University of Kiel, D-24105 Kiel, Germany; Clinic for General Surgery, Visceral, Thoracic, Transplantation and Pediatric Surgery, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany. Electronic address: atrauzold@email.uni-kiel.de. ·Cell Signal · Pubmed #27492861.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is characterized by both, overexpression of transforming growth factor (TGF)β and resistance of the tumor cells to many apoptosis-inducing stimuli. The latter negatively impacts the outcome of therapeutic efforts and represents one important mechanism which tumor cells utilize to escape the immune surveillance. Since TGFβ acts as a tumor promoter in advanced tumor stages and suppression of apoptosis is a known driver of tumor progression, it is possible that TGFβ functions as a crucial determinant of tumor cell sensitivity to apoptosis in PDAC. Here, we have studied the impact of TGFβ on TNF-related apoptosis inducing ligand (TRAIL)-induced signaling in PDAC cells. In TGFβ-responsive Panc1 and Colo357 cells, TGFβ1 reduced total and plasma membrane-associated levels of TRAIL-R1 but not those of TRAIL-R2. Consistent with the known predominant role of TRAIL-R1 in TRAIL-mediated signaling in PDAC, TGFβ1 inhibited TRAIL-induced DISC formation and apoptosis as well as phosphorylation of MAPKs and IκBα. Similarly, it also reduced signaling of TRAIL-R1 following its specific activation with an agonistic antibody. In contrast, specific TRAIL-R2 signaling remained unchanged. The TGFβ1 effect on TRAIL-R1 expression was mimicked by ectopic expression of a kinase-active version of the TGFβ type I receptor ALK5 (ALK5-T204D) but not by ALK5 double mutant lacking the ability to phosphorylate Smad proteins (RImL45-T204D). Moreover, TGFβ regulation of TRAIL-R1 was absent in two PDAC cell lines lacking the Smad4 gene DPC4 and siRNA-mediated silencing of Smad4 in Smad4-positive Panc1 cells abolished the TGFβ-mediated decrease in TRAIL-R1 expression, together showing that ALK5/Smad4 signaling is crucial for TGFβ regulation of TRAIL-R1 expression. Our results suggest a novel tumor-promoting function of TGFβ1. By downregulating TRAIL-R1, TGFβ1 may not only promote tumor escape from immune surveillance but also negatively impact on TRAIL- or TRAIL-R1-based therapy regimens for treatment of PDAC.

9 Article Proteinase-activated receptor 2 promotes TGF-β-dependent cell motility in pancreatic cancer cells by sustaining expression of the TGF-β type I receptor ALK5. 2016

Zeeh, Franziska / Witte, David / Gädeken, Thomas / Rauch, Bernhard H / Grage-Griebenow, Evelin / Leinung, Nadja / Fromm, Sofie Joline / Stölting, Stephanie / Mihara, Koichiro / Kaufmann, Roland / Settmacher, Utz / Lehnert, Hendrik / Hollenberg, Morley D / Ungefroren, Hendrik. ·First Department of Medicine, University of Lübeck, Lübeck, Germany. · Department of General Pharmacology, Institute of Pharmacology, University Medicine Greifswald, Greifswald, Germany. · Department of Physiology & Pharmacology and Department of Medicine, Inflammation Research Network-Snyder Institute for Chronic Diseases, University of Calgary, Cumming School of Medicine, Calgary, AB, Canada. · Department of General, Visceral and Vascular Surgery, Jena University Hospital, Jena, Germany. ·Oncotarget · Pubmed #27248167.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is characterized by high expression of transforming growth factor (TGF)-β and the G protein-coupled receptor proteinase-activated receptor 2 (PAR2), the latter of which functions as a cell-surface sensor for serine proteinases asscociated with the tumour microenvironment. Since TGF-β and PAR2 affect tumourigenesis by regulating migration, invasion and metastasis, we hypothesized that there is signalling crosstalk between them. Depleting PDAC and non-PDAC cells of PAR2 by RNA interference strongly decreased TGF-β1-induced activation of Smad2/3 and p38 mitogen-activated protein kinase, Smad dependent transcriptional activity, expression of invasion associated genes, and cell migration/invasion in vitro. Likewise, the plasminogen activator-inhibitor 1 gene in primary cultures of aortic smooth muscle cells from PAR2-/- mice displayed a greatly attenuated sensitivity to TGF-β1 stimulation. PAR2 depletion in PDAC cells resulted in reduced protein and mRNA levels of the TGF-β type I receptor activin receptor-like kinase 5 (ALK5). Forced expression of wild-type ALK5 or a kinase-active ALK5 mutant, but not a kinase-active but Smad-binding defective ALK5 mutant, was able to rescue TGF-β1-induced Smad3 activation, Smad dependent transcription, and cell migration in PAR2-depleted cells. Together, our data show that PAR2 is crucial for TGF-β1-induced cell motility by its ability to sustain expression of ALK5. Therapeutically targeting PAR2 may thus be a promising approach in preventing TGF-β-dependent driven metastatic dissemination in PDAC and possibly other stroma-rich tumour types.

10 Article Dasatinib blocks transcriptional and promigratory responses to transforming growth factor-beta in pancreatic adenocarcinoma cells through inhibition of Smad signalling: implications for in vivo mode of action. 2015

Bartscht, Tobias / Rosien, Benjamin / Rades, Dirk / Kaufmann, Roland / Biersack, Harald / Lehnert, Hendrik / Gieseler, Frank / Ungefroren, Hendrik. ·First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany. · Department of Radiation Oncology, UKSH, Campus Lübeck, D-23538, Lübeck, Germany. · Department of General, Visceral and Vascular Surgery, Jena University Hospital, D-07747, Jena, Germany. · First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany. hendrik.ungefroren@uksh.de. ·Mol Cancer · Pubmed #26588899.

ABSTRACT: BACKGROUND: We have previously shown in pancreatic ductal adenocarcinoma (PDAC) cells that the SRC inhibitors PP2 and PP1 effectively inhibited TGF-β1-mediated cellular responses by blocking the kinase function of the TGF-β type I receptor ALK5 rather than SRC. Here, we investigated the ability of the clinically utilised SRC/ABL inhibitor dasatinib to mimic the PP2/PP1 effect. METHODS: The effect of dasatinib on TGF-β1-dependent Smad2/3 phosphorylation, general transcriptional activity, gene expression, cell motility, and the generation of tumour stem cells was measured in Panc-1 and Colo-357 cells using immunoblotting, reporter gene assays, RT-PCR, impedance-based real-time measurement of cell migration, and colony formation assays, respectively. RESULTS: In both PDAC cell lines, dasatinib effectively blocked TGF-β1-induced Smad phosphorylation, activity of 3TPlux and pCAGA(12)-luc reporter genes, cell migration, and expression of individual TGF-β1 target genes associated with epithelial-mesenchymal transition and invasion. Moreover, dasatinib strongly interfered with the TGF-β1-induced generation of tumour stem cells as demonstrated by gene expression analysis and single cell colony formation. Dasatinib also inhibited the high constitutive migratory activity conferred on Panc-1 cells by ectopic expression of kinase-active ALK5. CONCLUSIONS: Our data suggest that the clinical efficiency of dasatinib may in part be due to cross-inhibition of tumour-promoting TGF-β signalling. Dasatinib may be useful as a dual TGF-β/SRC inhibitor in experimental and clinical therapeutics to prevent metastatic spread in late-stage PDAC and other tumours.

11 Article CD4 2015

Goebel, Lisa / Grage-Griebenow, Evelin / Gorys, Artur / Helm, Ole / Genrich, Geeske / Lenk, Lennart / Wesch, Daniela / Ungefroren, Hendrik / Freitag-Wolf, Sandra / Sipos, Bence / Röcken, Christoph / Schäfer, Heiner / Sebens, Susanne. ·Group Inflammatory Carcinogenesis; Institute for Experimental Medicine; Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein (UKSH) Campus Kiel ; Kiel, Germany. · Institute of Immunology; Christian-Albrechts-University and UKSH Campus Kiel ; Kiel, Germany. · First Department of Medicine; UKSH Campus Lübeck ; Lübeck, Germany. · Institute of Medical Informatics and Statistics; UKSH Campus Kiel ; Kiel, Germany. · Department of Pathology and Neuropathology; University Hospital Tübingen ; Tübingen, Germany. · Institute of Pathology; UKSH Campus Kiel ; Kiel, Germany. · Laboratory of Molecular Gastroenterology & Hepatology; Department of Internal Medicine I; UKSH Campus Kiel ; Kiel, Germany. ·Oncoimmunology · Pubmed #26137395.

ABSTRACT: Chronic pancreatitis (CP) is a risk factor of pancreatic ductal adenocarcinoma (PDAC) and characterized by a pronounced desmoplastic reaction with CD4

12 Article Tumor-associated macrophages exhibit pro- and anti-inflammatory properties by which they impact on pancreatic tumorigenesis. 2014

Helm, Ole / Held-Feindt, Janka / Grage-Griebenow, Evelin / Reiling, Norbert / Ungefroren, Hendrik / Vogel, Ilka / Krüger, Uwe / Becker, Thomas / Ebsen, Michael / Röcken, Christoph / Kabelitz, Dieter / Schäfer, Heiner / Sebens, Susanne. ·Institute for Experimental Medicine, Group Inflammatory Carcinogenesis, UK S-H Campus, Kiel, Germany. ·Int J Cancer · Pubmed #24458546.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) still ranking 4th in the order of fatal tumor diseases is characterized by a profound tumor stroma with high numbers of tumor-associated macrophages (TAMs). Driven by environmental factors, monocytes differentiate into M1- or M2-macrophages, the latter commonly regarded as being protumorigenic. Because a detailed analysis of TAMs in human PDAC development is still lacking, freshly isolated PDAC-derived TAMs were analyzed for their phenotype and impact on epithelial-mesenchymal-transition (EMT) of benign (H6c7) and malignant (Colo357) pancreatic ductal epithelial cells. TAMs exhibited characteristics of M1-macrophages (expression of HLA-DR, IL-1β, or TNF-α) and M2-macrophages (expression of CD163 and IL-10). In the presence of TAMs, H6c7, and Colo357 cells showed an elongated cell shape along with an increased expression of mesenchymal markers such as vimentin and reduced expression of epithelial E-cadherin. Similar to TAMs, in vitro generated M1- and M2-macrophages both mediated EMT in H6c7 and Colo357 cells. M1-macrophages acquired M2-characteristics during coculture that could be prevented by GM-CSF treatment. However, M1-macrophages still potently induced EMT in H6c7 and Colo357 cells although lacking M2-characteristics. Overall, these data demonstrate that TAMs exhibit anti- as well as proinflammatory properties that equally contribute to EMT induction in PDAC initiation and development.

13 Article Rac1b negatively regulates TGF-β1-induced cell motility in pancreatic ductal epithelial cells by suppressing Smad signalling. 2014

Ungefroren, Hendrik / Sebens, Susanne / Giehl, Klaudia / Helm, Ole / Groth, Stephanie / Fändrich, Fred / Röcken, Christoph / Sipos, Bence / Lehnert, Hendrik / Gieseler, Frank. ·First Department of Medicine, University Hospital Schleswig-Holstein (UKSH), Campus Lübeck, Lübeck, Germany. ·Oncotarget · Pubmed #24378395.

ABSTRACT: Transforming growth factor (TGF)-β1 promotes progression of pancreatic ductal adenocarcinoma (PDAC) by enhancing epithelial-mesenchymal transition, cell migration/invasion, and metastasis, in part by cooperating with the small GTPase Rac1. Prompted by the observation of higher expression of Rac1b, an alternatively spliced Rac1 isoform, in pancreatic ductal epithelial cells and in patients with chronic pancreatitis vs. PDAC, as well as in long-time vs. short-time survivors among PDAC patients, we asked whether Rac1b might negatively affect TGF-β1 prometastatic function. Interestingly, the non-malignant pancreatic ductal epithelial cell line H6c7 exhibited a higher ratio of active Rac1b to total Rac1b than the TGF-β1-responsive PDAC cell lines Panc-1 and Colo357. Notably, siRNA-mediated silencing of Rac1b increased TGF-β1/Smad-dependent migratory activities in H6c7, Colo357, and Panc-1 cells, while ectopic overexpression of Rac1b in Panc-1 cells attenuated TGF-β1-induced cell motility. Depletion of Rac1b in Panc-1 cells enhanced TGF-β1/Smad-dependent expression of promoter-reporter genes and of the endogenous Slug gene. Moreover, Rac1b depletion resulted in a higher and more sustained C-terminal phosphorylation of Smad3 and Smad2, suggesting that Rac1b is involved in Smad2/3 dephosphorylation/inactivation. Since pharmacologic or siRNA-mediated inhibition of Smad3 but not Smad2 was able to alleviate the Rac1b siRNA effect on TGF-β1-induced cell migration, our results suggests that Rac1b inhibits TGF-β1-induced cell motility in pancreatic ductal epithelial cells by blocking the function of Smad3. Moreover, Rac1b may act as an endogenous inhibitor of Rac1 in TGF-β1-mediated migration and possibly metastasis. Hence, it could be exploited for diagnostic/prognostic purposes or even therapeutically in late-stage PDAC as an antimetastatic agent.

14 Article Differential roles of Smad2 and Smad3 in the regulation of TGF-β1-mediated growth inhibition and cell migration in pancreatic ductal adenocarcinoma cells: control by Rac1. 2011

Ungefroren, Hendrik / Groth, Stephanie / Sebens, Susanne / Lehnert, Hendrik / Gieseler, Frank / Fändrich, Fred. ·Clinic for Applied Cellular Medicine, University Hospital Schleswig-Holstein (UKSH) Campus Kiel, 24105 Kiel, Germany. hendrik.ungefroren@uk-sh.de ·Mol Cancer · Pubmed #21624123.

ABSTRACT: BACKGROUND: Progression of pancreatic ductal adenocarcinoma (PDAC) is largely the result of genetic and/or epigenetic alterations in the transforming growth factor-beta (TGF-β)/Smad signalling pathway, eventually resulting in loss of TGF-β-mediated growth arrest and an increase in cellular migration, invasion, and metastasis. These cellular responses to TGF-β are mediated solely or partially through the canonical Smad signalling pathway which commences with activation of receptor-regulated Smads (R-Smads) Smad2 and Smad3 by the TGF-β type I receptor. However, little is known on the relative contribution of each R-Smad, the possible existence of functional antagonism, or the crosstalk with other signalling pathways in the control of TGF-β1-induced growth inhibition and cell migration. Using genetic and pharmacologic approaches we have inhibited in PDAC cells endogenous Smad2 and Smad3, as well as a potential regulator, the small GTPase Rac1, and have analysed the consequences for TGF-β1-mediated growth inhibition and cell migration (chemokinesis). RESULTS: SiRNA-mediated silencing of Smad3 in the TGF-β responsive PDAC cell line PANC-1 reduced TGF-β1-induced growth inhibition but increased the migratory response, while silencing of Smad2 enhanced growth inhibition but decreased chemokinesis. Interestingly, siRNA-mediated silencing of the small GTPase Rac1, or ectopic expression of a dominant-negative Rac1 mutant largely mimicked the effect of Smad2 silencing on both TGF-β1-induced growth inhibition, via upregulation of the cdk inhibitor p21WAF1, and cell migration. Inhibition of Rac1 activation reduced both TGF-β1-induction of a Smad2-specific transcriptional reporter and Smad2 C-terminal phosphorylation in PDAC cells while Smad3-specific transcriptional activity and Smad3 C-terminal phosphorylation appeared increased. Disruption of autocrine TGF-β signalling in PANC-1 cells rendered cells less susceptible to the growth-suppressive effect of Rac1 inhibition, suggesting that the decrease in "basal" proliferation upon Rac1 inhibition was caused by potentiation of autocrine TGF-β growth inhibition. CONCLUSIONS: In malignant cells with a functional TGF-β signalling pathway Rac1 antagonizes the TGF-β1 growth inhibitory response and enhances cell migration by antagonistically regulating Smad2 and Smad3 activation. This study reveals that Rac1 is prooncogenic in that it can alter TGF-β signalling at the R-Smad level from a tumour-suppressive towards a tumour-promoting outcome. Hence, Rac1 might represent a viable target for therapeutic intervention to inhibit PDAC progression.

15 Article Differential roles of Src in transforming growth factor-ß regulation of growth arrest, epithelial-to-mesenchymal transition and cell migration in pancreatic ductal adenocarcinoma cells. 2011

Ungefroren, Hendrik / Sebens, Susanne / Groth, Stephanie / Gieseler, Frank / Fändrich, Fred. ·First Department of Medicine, UKSH, Lübeck, Germany. hendrik.ungefroren@uk-sh.de ·Int J Oncol · Pubmed #21225226.

ABSTRACT: Both transforming growth factor (TGF)-ß and the non-receptor tyrosine kinase Src play major roles during tumorigenesis by regulating cell growth, epithelial-to-mesenchymal transition (EMT), migration/invasion and metastasis, but little is known about the signaling crosstalk between them. To interfere with Src function in vitro and in vivo many studies have employed the pharmacologic Src inhibitors PP2 and PP1. Both agents have recently been shown to be powerful inhibitors of TGF-ß receptor type I/ALK5 and type II. As this situation prohibited any definite conclusions with respect to the relative contribution of TGF-ß vs. Src signaling, we decided to reappraise a potential role of Src in TGF-ß1-mediated cellular responses using RNA and dominant-negative (dn) interference to block Src expression and function, respectively. In TGF-ß-responsive pancreatic ductal adenocarcinoma (PDAC) cells, we show that Src is activated by TGF-ß1 and that its specific inhibition strongly attenuated basal proliferation and enhanced TGF-ß1-mediated growth arrest. However, Src inhibition was unable to impair TGF-ß1-controlled EMT as evidenced by cell morphology and regulation of the epithelial marker E-cadherin. Despite its dispensibility for TGF-ß-induced EMT, specific inhibition of Src dramatically reduced basal and TGF-ß1-induced cell migration in Panc-1 cells as measured with a novel real-time migration assay (xCELLigence DP system). Biochemically, dnSrc inhibition failed to block TGF-ß1/ALK5-induced activation of Smad2 and Smad3, but partially inhibited transcriptional activation of TGF-ß/Smad-responsive reporter genes, and effectively blocked basal and TGF-ß1-induced activation of p38 MAPK. Together, the data provide evidence for a role of Src in the regulation of basal proliferation as well as in basal and TGF-ß1-mediated cell motility but not EMT in TGF-ß-responsive pancreatic (tumor) cells.