Browsing by Author "Demir, Ihsan Ekin"

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Clinically Actionable Strategies for Studying Neural Influences in Cancer
(CELL PRESS, 2020-01-01) Demir, Ihsan Ekin; Reyes, Carmen Mota; Alrawashdeh, Wasfi; Ceyhan, Guralp O.; Deborde, Sylvie; Friess, Helmut; Gorgulu, Kivanc; Istvanffy, Rouzanna; Jungwirth, David; Kuner, Rohini; Maryanovich, Maria; Na'ara, Shorook; Renders, Simon; Saloman, Jami L.; Scheff, Nicole N.; Steenfadt, Hendrik; Stupakov, Pavel; Thiel, Vera; Verma, Divij; Yilmaz, Bengi Su; White, Ruth A.; Wang, Timothy C.; Wong, Richard J.; Frenette, Paul S.; Gil, Ziv; Davis, Brian M.
Neuro-glial activation is a recently identified hallmark of growing cancers. Targeting tumor hyperinnervation in preclinical and small clinical trials has yielded promising antitumor effects, highlighting the need of systematic analysis of neural influences in cancer (NIC). Here, we outline the strategies translating these findings from bench to the clinic.
Diabetes and Weight Loss Are Associated With Malignancies in Patients With Intraductal Papillary Mucinous Neoplasms
(ELSEVIER SCIENCE INC, 2021-01-01) Pergolini, Ilaria; Jaeger, Carsten; Safak, Okan; Goess, Ruediger; Novotny, Alexander; Ceyhan, Guralp O.; Friess, Helmut; Demir, Ihsan Ekin
BACKGROUND \& AIMS: The role of diabetes in intraductal papillary mucinous neoplasms (IPMNs) is not known. We investigated the prevalence of diabetes among patients with resected IPMNs and the association between diabetes, clinical and morphological features, and high-grade dysplasia or invasive cancer. METHODS: We collected clinical, pathology, laboratory, and demographic data from 134 patients who underwent pancreatic resection for IPMN from a referral center in Germany. We identified 50 patients with diabetes (37\%). RESULTS: Higher proportions of patients with diabetes were male and older, but did not have increased body mass index, compared to patients without diabetes. Diabetes was significantly associated with main-duct involvement (odds ratio {[}OR], 2.827
Drain use in pancreatic surgery: Results from an international survey among experts in the field
(MOSBY-ELSEVIER, 2022-01-01) Pergolini, Ilaria; Schorn, Stephan; Goess, Ruediger; Novotny, Alexander R.; Ceyhan, Guralp O.; Friess, Helmut; Demir, Ihsan Ekin; Surg, Collaborators Int Pancreatic
Background: Drain use in pancreatic surgery remains controversial. This survey sought to evaluate habits, experiences, and opinions of experts in the field on the use of drains to provide interesting insights for pancreatic surgeons worldwide. Methods: An online survey designed via Google Forms was sent in December 2020 to experienced surgeons of the International Study Group for Pancreatic Surgery. Results: Forty-two surgeons (42/63, 67\%) completed the survey. During their career, 74\% (31/42) performed personally >500 pancreatic resections
Future directions in preclinical and translational cancer neuroscience research
(NATURE PORTFOLIO, 2020-01-01) Demir, Ihsan Ekin; Reyes, Carmen Mota; Alrawashdeh, Wasfi; Ceyhan, Gueralp O.; Deborde, Sylvie; Friess, Helmut; Goerguelue, Kivanc; Istvanffy, Rouzanna; Jungwirth, David; Kuner, Rohini; Maryanovich, Maria; Na'ara, Shorook; Renders, Simon; Saloman, Jami L.; Scheff, Nicole N.; Steenfadt, Hendrik; Stupakov, Pavel; Thiel, Vera; Verma, Divij; Yilmaz, Bengi Su; White, Ruth A.; Wang, Timothy C.; Wong, Richard J.; Frenette, Paul S.; Gil, Ziv; Davis, Brian M.; Res, Neural Influences Can N.I.C. Int
Recent advances in cancer neuroscience necessitate the systematic analysis of neural influences in cancer as potential therapeutic targets in oncology. Here we outline recommendations for future preclinical and translational research in this field.
Indirect cholinergic activation slows down pancreatic cancer growth and tumor-associated inflammation
(BMC, 2020-01-01) Pfitzinger, Paulo L.; Fangmann, Laura; Wang, Kun; Demir, Elke; Guerlevik, Engin; Fleischmann-Mundt, Bettina; Brooks, Jennifer; D'Haese, Jan G.; Teller, Steffen; Hecker, Andreas; Jesinghaus, Moritz; Jaeger, Carsten; Ren, Lei; Istvanffy, Rouzanna; Kuehnel, Florian; Friess, Helmut; Ceyhan, Guralp Onur; Demir, Ihsan Ekin
Background Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine. Methods We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/-physostigmine/pyridostigmine (n = 30 mice). Human PCa specimens (n = 39) were analyzed for the impact of cancer AChE expression on tumor stage and survival. Results We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves. Conclusion For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.
Localisation analysis of nerves in the mouse pancreas reveals the sites of highest nerve density and nociceptive innervation
(WILEY, 2020-01-01) Saricaoglu, Oemer Cemil; Teller, Steffen; Wang, Xiaobo; Wang, Shenghan; Stupakov, Pavel; Heinrich, Tobias; Istvanffy, Rouzanna; Friess, Helmut; Ceyhan, Gueralp O.; Demir, Ihsan Ekin
Background Neuropathy and neuro-inflammation drive the severe pain and disease progression in human chronic pancreatitis and pancreatic cancer. Mice, especially genetically induced-mouse models, have been increasingly utilized in mechanistic research on pancreatic neuropathy, but the normal ``peripheral neurobiology{''} of the mouse pancreas has not yet been critically compared to human pancreas. Methods We introduced a standardized tissue-harvesting technique that preserves the anatomic orientation of the mouse pancreas and allows complete sectioning in an anterior to posterior fashion. We applied immunohistochemistry and quantitative colorimetry of all nerves from the whole organ for studying pancreatic neuro-anatomy. Key Results Nerves in the mouse pancreas appeared as ``clusters{''} of nerve trunks in contrast to singly distributed nerve trunks in the human pancreas. Nerve trunks in the mouse pancreas were exclusively found around intrapancreatic blood vessels, and around lymphoid structures. The majority of nerve trunks were located in the pancreatic head (0.15 +/- 0.08\% of tissue area) and the anterior/front surface of the corpus/body (0.17 +/- 0.27\%), thus significantly more than in the tail (0.02 +/- 0.02\%, P = .006). Nerves in the tail included a higher proportion of nociceptive fibers, but the absolute majority, ie, ca. 70\%, of all nociceptive fibers, were localized in the head. Mice heterozygous for Bdnf knockout allele (Bdnf(+/-)) exhibited enrichment of nitrergic nerve fibers specifically in the head and corpus. Conclusions \& Inferences Neuro-anatomy of the ``mesenteric type{''} mouse pancreas is highly different from the ``compact{''} human pancreas. Studies that aim at reproducing human pancreatic neuro-phenomena in mouse models should pay diligent attention to these anatomic differences.
Mechanisms of T-Cell Exhaustion in Pancreatic Cancer
(MDPI, 2020-01-01) Saka, Didem; Gokalp, Muazzez; Piyade, Betul; Cevik, Nedim Can; Sever, Elif Arik; Unutmaz, Derya; Ceyhan, Guralp O.; Demir, Ihsan Ekin; Asimgil, Hande
T-cell exhaustion is a phenomenon that represents the dysfunctional state of T cells in chronic infections and cancer and is closely associated with poor prognosis in many cancers. The endogenous T-cell immunity and genetically edited cell therapies (CAR-T) failed to prevent tumor immune evasion. The effector T-cell activity is perturbed by an imbalance between inhibitory and stimulatory signals causing a reprogramming in metabolism and the high levels of multiple inhibitory receptors like programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), and Lymphocyte-activation gene 3 (Lag-3). Despite the efforts to neutralize inhibitory receptors by a single agent or combinatorial immune checkpoint inhibitors to boost effector function, PDAC remains unresponsive to these therapies, suggesting that multiple molecular mechanisms play a role in stimulating the exhaustion state of tumor-infiltrating T cells. Recent studies utilizing transcriptomics, mass cytometry, and epigenomics revealed a critical role of Thymocyte selection-associated high mobility group box protein (TOX) genes and TOX-associated pathways, driving T-cell exhaustion in chronic infection and cancer. Here, we will review recently defined molecular, genetic, and cellular factors that drive T-cell exhaustion in PDAC. We will also discuss the effects of available immune checkpoint inhibitors and the latest clinical trials targeting various molecular factors mediating T-cell exhaustion in PDAC.
Molecular Profiling in Pancreatic Cancer: Current Role and Its Impact on Primary Surgery
(KARGER, 2019-01-01) Mota Reyes, Carmen; Dogruoez, Alper; Istvanffy, Rouzanna; Friess, Helmut; Ceyhan, Gueralp O.; Demir, Ihsan Ekin
Background: The advent of next-generation sequencing technologies has enabled the identification of molecular subtypes of pancreatic ductal adenocarcinoma (PDAC) with different biological traits and clinically targetable features. Summary: Although current chemotherapy trials are currently exploiting this knowledge, these molecular subtypes have not yet sufficiently caught the attention of surgeons. In fact, integration of these molecular subtypes into the timing of surgery can in theory improve patient outcome. Here, we present the molecular subtypes of PDAC from the surgeon's perspective and a clinically applicable algorithm that integrates the molecular subtyping of PDAC preoperatively into the decision of primary surgery versus neoadjuvant therapy. Furthermore, we point out the potential of ``tailored{''} (in addition to conventional) neoadjuvant treatment for exploiting the molecular subtypes of PDAC. Key Messages: We believe that for surgeons, the preoperative knowledge on the subtype of PDAC can properly guide in deciding between upfront surgery versus neoadjuvant treatment for improving patient outcome.
Neoadjuvant therapy in pancreatic cancer: what is the true oncological benefit?
(SPRINGER, 2020-01-01) Ren, Lei; Mota Reyes, Carmen; Friess, Helmut; Demir, Ihsan Ekin
Background Neoadjuvant therapies (neoTx) have revolutionized the treatment of borderline resectable (BR) and locally advanced (LA) pancreatic cancer (PCa) by significantly increasing the rate of R0 resections, which remains the only curative strategy for these patients. However, there is still room for improvement of neoTx in PCa. Purpose Here, we aimed to critically analyze the benefits of neoTx in LA and BR PCa and its potential use on patients with resectable PCa. We also explored the feasibility of arterial resection (AR) to increase surgical radicality and the incorporation of immunotherapy to optimize neoadjuvant approaches in PCa. Conclusion For early stage, i.e., resectable, PCa, there is not enough scientific evidence for routinely recommending neoTx. For LA and BR PCa, optimization of neoadjuvant therapy necessitates more sophisticated complex surgical resections, machine learning and radiomic approaches, integration of immunotherapy due to the high antigen load, standardized histopathological assessment, and improved multidisciplinary communication.
Organoids to Study Intestinal Nutrient Transport, Drug Uptake and Metabolism - Update to the Human Model and Expansion of Applications
(FRONTIERS MEDIA SA, 2020-01-01) Zietek, Tamara; Giesbertz, Pieter; Ewers, Maren; Reichart, Florian; Weinmueller, Michael; Urbauer, Elisabeth; Haller, Dirk; Demir, Ihsan Ekin; Ceyhan, Guralp O.; Kessler, Horst; Rath, Eva
Intestinal transport and sensing processes and their interconnection to metabolism are relevant to pathologies such as malabsorption syndromes, inflammatory diseases, obesity and type 2 diabetes. Constituting a highly selective barrier, intestinal epithelial cells absorb, metabolize, and release nutrients into the circulation, hence serving as gatekeeper of nutrient availability and metabolic health for the whole organism. Next to nutrient transport and sensing functions, intestinal transporters including peptide transporter 1 (PEPT1) are involved in the absorption of drugs and prodrugs, including certain inhibitors of angiotensin-converting enzyme, protease inhibitors, antivirals, and peptidomimetics like beta-lactam antibiotics. Here, we verify the applicability of 3D organoids forin vitroinvestigation of intestinal biochemical processes related to transport and metabolism of nutrients and drugs. Establishing a variety of methodologies including illustration of transporter-mediated nutrient and drug uptake and metabolomics approaches, we highlight intestinal organoids as robust and reliable tool in this field of research. Currently usedin vitromodels to study intestinal nutrient absorption, drug transport and enterocyte metabolism, such as Caco-2 cells or rodent explant models are of limited value due to their cancer and non-human origin, respectively. Particularly species differences result in poorly correlative data and findings obtained in these models cannot be extrapolated reliably to humans, as indicated by high failure rates in drug development pipelines. In contrast, human intestinal organoids represent a superior model of the intestinal epithelium and might help to implement the 3Rs (Reduction, Refinement and Replacement) principle in basic science as well as the preclinical and regulatory setup.
Patterns and Relevance of Langerhans Islet Invasion in Pancreatic Cancer
(MDPI, 2021-01-01) Goess, Ruediger; Mutgan, Ayse Ceren; Calisan, Umut; Erdogan, Yusuf Ceyhun; Ren, Lei; Jager, Carsten; Safak, Okan; Stupakov, Pavel; Istvanffy, Rouzanna; Friess, Helmut; Ceyhan, Guralp O.; Demir, Ihsan Ekin
Simple Summary The pathogenesis of pancreatic cancer-associated diabetes mellitus is poorly understood. We analyzed tumor infiltration into Langerhans islets and characterized it systematically for the first time, identifying four different main patterns of islet invasion. In a cohort of 68 pancreatic ductal adenocarcinoma (PDAC) patients, these islet invasion patterns were not related to occurrence of diabetes mellitus. However, severe islet invasion was associated with worsened overall survival. Background: Pancreatic cancer-associated diabetes mellitus (PC-DM) is present in most patients with pancreatic cancer, but its pathogenesis remains poorly understood. Therefore, we aimed to characterize tumor infiltration in Langerhans islets in pancreatic cancer and determine its clinical relevance. Methods: Langerhans islet invasion was systematically analyzed in 68 patients with pancreatic ductal adenocarcinoma (PDAC) using histopathological examination and 3D in vitro migration assays were performed to assess chemoattraction of pancreatic cancer cells to islet cells. Results: Langerhans islet invasion was present in all patients. We found four different patterns of islet invasion: (Type I) peri-insular invasion with tumor cells directly touching the boundary, but not penetrating the islet
Regulatory T Cells in Pancreatic Cancer: Of Mice and Men
(MDPI, 2022-01-01) Reyes, Carmen Mota; Demir, Elke; Cifcibasi, Kaan; Istvanffy, Rouzanna; Friess, Helmut; Demir, Ihsan Ekin
Simple Summary Regulatory T cells (Treg) are a major immunosuppressive cell subset in the pancreatic tumor microenvironment. Tregs influence tumor growth by acting either directly on cancer cells or via the inhibition of effector immune cells. Treg cells form a partially redundant network with other immunosuppressive cells such as myeloid-derived suppressor cells (MDSC) that confer robustness to tumor immunosuppression and resistance to immunotherapy. The results obtained in preclinical studies, whereupon Treg depletion, MDSCs concomitantly decreased in early tumors whereas an inverse association was seen in advanced PCa, urge a comprehensive analysis of the immunosuppressive profile of PCa throughout tumorigenesis. One relevant context to analyse these compensatory mechanisms may be patients with locally advanced PCa undergoing neoadjuvant therapy (neoTx). In order to understand these dynamics and to uncover stage-specific actional strategies involving Tregs, pre-clinical models that allow the administration of neoTx to different stages of PCa may be a very useful platform. Regulatory T cells (Treg) are one of the major immunosuppressive cell subsets in the pancreatic tumor microenvironment. Tregs influence tumor growth by acting either directly on cancer cells or via the inhibition of effector immune cells. Treg cells mechanisms form a partially redundant network with other immunosuppressive cells such as myeloid-derived suppressor cells (MDSC) that confer robustness to tumor immunosuppression and resistance to immunotherapy. The results obtained in preclinical studies where after Treg depletion, MDSCs concomitantly decreased in early tumors whereas an inverse association was seen in advanced PCa, urge a comprehensive analysis of the immunosuppressive profile of PCa throughout tumorigenesis. One relevant context to analyse these complex compensatory mechanisms may be the tumors of patients who underwent neoTx. Here, we observed a parallel decrease in the numbers of both intratumoral Tregs and MDSC after neoTx even in locally advanced PCa. NeoTx also led to decreased amounts of alpha SMA(+) myofibroblastic cancer-associated fibroblasts (myCAF) and increased proportions of CD8(+) cytotoxic T lymphocytes in the tumor. In order to understand these dynamics and to uncover stage-specific actional strategies involving Tregs, pre-clinical models that allow the administration of neoTx to different stages of PCa may be a very useful platform.
Surgery and the kings of medical science Invited Commentary: ``Publication activity of chief and senior general/visceral surgeons in German university hospitals - a ten-year analysis'', Bockmann et al.
(SPRINGER, 2021-01-01) Demir, Ihsan Ekin; Ceyhan, Guralp O.; Friess, Helmut
Background Surgeons are frequently compared in terms of their publication activity to members of other disciplines who publish in journals with naturally higher impact factors. The time intensity of daily clinical duties in surgery is yet not comparable to that of these competitor disciplines. Purpose Here, we aimed to critically comment on ways for improving the academic productivity of university surgerons. Conclusions To ensure high-quality science in surgery, it is imperative that surgeons actively ask for and generate the time for high-quality research. This necessitates coordinated and combined efforts of leading university surgeons at the political level and effective presentation of the magnificent studies performed by young and talented university surgeons.
Targeting nNOS ameliorates the severe neuropathic pain due to chronic pancreatitis
(ELSEVIER, 2019-01-01) Demir, Ihsan Ekin; Heinrich, Tobias; Carty, Dominique G.; Saricaoglu, Omer Cemil; Klauss, Sarah; Teller, Steffen; Kehl, Timo; Reyes, Carmen Mota; Tieftrunk, Elke; Lazarou, Maria; Bahceci, Dorukhan H.; Gokcek, Betul; Ucurum, Bahar E.; Maak, Matthias; Diakopoulos, Kalliope N.; Lesina, Marina; Schemann, Michael; Erkane, Mert; Krueger, Achim; Algul, Hana; Friess, Helmut; Ceyhan, Guralp O.
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+/-) mice revealed neuronal enrichment of nNOS to be a consequence of BDNI loss in the progressively destroyed pancreatic tissue. Mechanistically, nNOS upregulation in sensory neurons was induced by tryptase secreted from perineural mast cells. In a head-to-head comparison of several genetically induced, painless mouse models of PCa (KPC, KC mice) or CP (Ptf1a-Cre
Targeting the undruggable oncogenic KRAS: the dawn of hope
(AMER SOC CLINICAL INVESTIGATION INC, 2022-01-01) Asimgil, Hande; Ertetik, Utku; Cevik, Nedim Can; Ekizce, Menar; Dogruoez, Alper; Goekalp, Muazzez; Arik-Sever, Elif; Istvanffy, Rouzanna; Friess, Helmut; Ceyhan, Guralp Onur; Demir, Ihsan Ekin
KRAS mutations are the drivers of various cancers, including non-small cell lung cancer, colon cancer, and pancreatic cancer. Over the last 30 years, immense efforts have been made to inhibit KRAS mutants and oncogenic KRAS signaling using inhibitors. Recently, specific targeting of KRAS mutants with small molecules revived the hopes for successful therapies for lung, pancreatic, and colorectal cancer patients. Moreover, advances in gene editing, protein engineering, and drug delivery formulations have revolutionized cancer therapy regimens. New therapies aim to improve immune surveillance and enhance antitumor immunity by precisely targeting cancer cells harboring oncogenic KRAS. Here, we review recent KRAS-targeting strategies, their therapeutic potential, and remaining challenges to overcome. We also highlight the potential synergistic effects of various combinatorial therapies in preclinical and clinical trials.
Venous resection during pancreatectomy for pancreatic cancer: a systematic review
(AME PUBLISHING COMPANY, 2019-01-01) Wang, Xiaobo; Demir, Ihsan Ekin; Schorn, Stephan; Jaeger, Carsten; Scheufele, Florian; Friess, Helmut; Ceyhan, Guralp O.
Pancreatic cancer is one of the most aggressive and lethal malignancies with a dismal prognosis and survival. The curative effects of venous resection (VR) in pancreatic cancer remain controversial. A systematic literature search was performed in PubMed, Embase and the Cochrane Library. The overall postoperative complications, perioperative mortality, histopathology, and long-term survival were compared between patients undergoing pancreatectomy combined with (VR+ group) or without (VR- group) VR. Forty-one studies were included in the systematic review. Pancreatectomy combined with VR required longer operation time and led to increased perioperative blood loss, whereas postoperative complications were similar. Patients in the VR+ group showed larger tumors and reduced R0 rates. Regarding long-term survival, patients with VR+ seemed to have impaired 1-, 3-, and 5-year survival. Based on our results, VR in pancreatic cancer is a safe and feasible procedure. Given the fact that patients have miserable outcomes and survival in the palliative setting alone, extended resection including VR is required for the purpose of achieving radical resection.