- Email: [email protected]
TLR2 and TLR4 predict favourable prognosis in early pancreatic cancer
Abstracts / Pancreatology 17 (2017) S1eS142 2 University Hospital of Bologna, Department of Medical Oncology, Italy 3 University Hospital of Pisa, Department of Medical Oncology, Italy 4 University Hospital of Pisa, Cancer Pharmacology Lab, AIRC-Start-Up, Italy 5 VU University Medical Center, Department of Medical Oncology, Netherlands
Introduction: FOLFIRINOX chemotherapy has become standard upfront treatment in patients with advanced pancreatic ductal adenocarcinoma (PDAC). However, only one third of the patients show clinical benefit and biomarkers to select these patients are warranted. Due to their high stability in plasma, circulating microRNAs (miRNAs) have been proposed as minimally-invasive biomarkers. Aims: Our aim is to identify blood-based miRNAs as predictive and monitoring biomarkers in patients with PDAC. Patients & methods: Patients with locally advanced and metastatic PDAC receiving first-line FOLFIRINOX (n¼54) were prospectively enrolled. Patients were classified as 'progressive' or 'non-progressive', based on time to progression (cut-off of 6.4 months). MiRNAs were isolated from plasma collected before and after 5-6 cycles of FOLFIRINOX treatment. Differentially expressed miRNAs were identified in a discovery cohort using a microarray panel. To analyze their value as monitoring biomarkers, candidate miRNAs were evaluated in a validation cohort by RT-PCR in extracellular vesicles of 16 non-progressive patients. Results: MiR-29a emerged as a potential biomarker in both analyses. MiR-29a was significantly upregulated (2$36-fold change, p<0$0024) in extracellular vesicles after five cycles of FOLFIRINOX in patients without tumor progression. Interestingly, the expression of miR-29a in extracellular vesicles was significantly higher than circulating free miR-29a expression (p<0$0001). In addition, three miRNAs were considered to be normalising miRNAs of which miR-93 showed the most stable expression. Conclusion: Upregulation of miR-29a in extracellular vesicles can monitor the progression of PDAC in patients treated with FOLFIRINOX. This underlines the opportunity to further explore the clinical utility of miRNAs as biomarkers to select the optimal treatment strategy.
Abstract ID: 1915. The contribution of Lymphotoxin from PanINs to pancreatic tumor development Gitta Maria Wanner-Seleznik 1, Theresia Reding 1, Conny Waschkies 1, Anurag Gupta 1, Daniela Lenggenhager 2, Mathias Heikenwalder 3, Rolf Graf 1 1 Swiss HPB Center, Visceral & Transplantation Surgery, University Hospital Zurich, Switzerland 2 Institute of Pathology, University Hospital Zurich, Switzerland 3 Institute for Virology, Helmholtz-Centre Munich, German Cancer Center (DKFZ) Heidelberg, Germany
Introduction: Pancreatic inflammation is a well-known risk factor for pancreatic ductal adenocarcinoma (PDAC) development. Still, little is known about the cellular and molecular mechanisms how inflammation promotes pre-malignant lesions and tumor progression. We have previously shown that patients suffering from chronic pancreatitis or pancreatic cancer show increased expression of lymphotoxin (LT) in the pancreas. Furthermore, in mice LT overexpression in the exocrine pancreas leads to pancreatitis (chronic, autoimmune). Aims: To assess the role of LT-mediated inflammation in pancreatic carcinogenesis. Materials & methods: We established a mouse model by intercrossing p48+/Cre;Kras+/G12D (KC) mice to transgenic mice overexpressing LT in pancreas (Tg(Ela1-Lta,b); p48+/CreTg+; KrasG12Dflox/+) (LTKC). To evaluate tumor development, we introduced a deletion in the TP53 tumor suppressor gene (KPC; LTKPC). Immunohistochemistry and RT-PCR were used to describe the inflammatory signature. In KPC and LTKPC animals tumor growth was assessed by MRI, furthermore tumors were compared
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histologically and biochemically focusing mostly on the distribution of immune cells and formation of tertiary lymphoid organs (TLOs). Results: LT overexpression dramatically accelerated the development of pre-malignant lesions in KC animals. 8 week-old LTKC mice already showed extensive PanIN lesions, which are normally observed in 16-weekold KC animals. LTKPC animals in the survival analysis succumbed to tumors significantly earlier than KPC group. As hypothesized LT overexpression contributed to the formation of TLOs in the pancreatic tumors. Conclusion: We conclude that LT not only accelerated PanIN lesions, but also tumor growth. Moreover, LT overexpression led to changes in tumor microenvironment, which suggests that TLO formation may have a role in pancreatic cancer.
Abstract ID: 1917. Parkin mediated Mitophagy in Acute Pancreatitis Preshit Ravindra Wagh 1, Matthias Sendler 1, Ujwal Mukund Mahajan 2, Frank Ulrich Weiss 1, Markus Lerch 1, Julia Mayerle 2 1 Department of Medicine A, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany 2 Medizinische Klinik und Poliklinik II, Klinikum der LMU MünchenGrosshadern, München, Germany
Introduction: AP is associated with premature activation of digestive proteases in the pancreas resulting in cell death. Previously it has been reported that mitochondrial dysfunction and impaired autophagy contribute to the pathogenesis of AP. Except for their main role in energy production, mitochondria are also implicated in fundamental cellular processes, including ion homeostasis, lipid metabolism, and initiation of apoptotic cell death. However, the inter-relationship between mitochondrial dysfunction and autophagy with regard to cell damage in AP remains elusive. Aims: Investigate the role of E3-ubiquitin-ligase PARK2 (Parkin) mediated Mitophagy in AP. Materials & methods: Mitophagy was studied in parkin-/- and C57Bl/6 mice upon induction of mild AP (caerulein model) and severe AP (l-arginine model). Protease activation, cell death and mitochondrial membrane potential (DJm) was investigated in isolated acini stimulated with supramaximal CCK. Results: Induction of mitophagy in AP can be seen by accumulation of PINK-1 and parkin in the mitochondrial subcellular fraction. Parkin -/animals develop pancreatitis in a miId AP with a restitution ad integrum at 24hr; in a severe AP parkin-/- increases the extent of pancreatic necrosis at 72 hrs in parkin-/- animals. In acinar cells of parkin-/- mice CCK significantly decreased DJm and increased the cell death rate. Conclusion: Parkin dependent mitophagy seems to have an important impact on cell death regulation. Parkin-mediated mitophagy plays a significant role in the regeneration of the pancreas in a mild AP and its absence aggravates severe AP, lack of parkin is at least in parts responsible for necrosis in AP and in acinar cells.
Abstract ID: 1925. TLR2 and TLR4 predict favourable prognosis in early pancreatic cancer €nen 3, Caj €m 2, Harri Mustonen 3, Hanna Seppa Mira Lanki 1, Jaana Hagstro Haglund 1 1 Department of Surgery, Helsinki University Hospital, Research Programs Unit, Translational Cancer Biology, University of Helsinki, Finland 2 Department of Pathology and Oral Pathology, Helsinki University Hospital, Research Programs Unit, University of Helsinki, Finland 3 Department of Surgery, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
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Abstracts / Pancreatology 17 (2017) S1eS142
Introduction: Toll-like receptors (TLRs) play an essential role in our innate immune system and are a point of interest in contemporary cancer research. So far TLRs have shown promising prognostic value in adenocarcinomas of the mouth, colon and ovaries, but the role of TLRs in pancreatic ductal adenocarcinoma (PDAC) is yet to be explored. Aims: We set out to investigate whether TLR expression could be used for prognostic evaluation in PDAC as well. Patients & methods: Our study comprised of 154 stage I-III PDAC patients surgically treated at Helsinki University Hospital between 2000 and 2011. Patients receiving neoadjuvant therapy were excluded from the study. We used tissue microarrays and immunohistochemistry to assess the expression of TLR2 and TLR4 in PDAC tissue, and we matched staining results against clinicopathological parameters using Fischer’s test. For survival analysis we used the Kaplan-Meier method and log-rank test, and the Cox regression proportional hazard model for univariate and multivariate analyses. Results: High TLR2 expression was observed in 51 (34%) and high TLR4 in 50 (33%) patients. Overall neither marker showed correlation with patient mortality. However, multivariate analysis showed that high TLR2 expression predicted lower death risk when tumor size was less than 30mm (HR¼0.32; p¼0.009; 95% CI 0.13-0.75), and that high TLR4 expression predicted lower death risk in patients with lymph node negative disease (HR¼0.21; p¼0.006; 95% CI 0.07-0.65). Conclusion: We found high TLR2 and TLR4 expression to be independent factors of better prognosis in PDAC patients with early disease.
Abstract ID: 1926. Genetic determinants of telomere length and risk of pancreatic cancer: a PANDoRA study Daniele Campa 1, Martina Matarazzi 1, Raffaele Pezzilli 2, Ugo Boggi 3, Gabriele Capurso 4, Renata Talar-Wojnarowska 5, Juozas Kupcinskas 6, Thilo Hackert 7, Pavel Vodicka 8, Hermann Brenner 9, Kay-Tee Khaw 10, Timothy J. Key 11, Stefano Landi 1, Cosmeri Rizzato 1, Francesca Tavano 12, Manuel Gentiluomo 1, Eithne Costello 13, Andrea Mambrini 14, Rita T. Lawlor 15, Pavel Soucek 16, Rudolf Kaaks 17, Anna Caterina Milanetto 18, Ofure Obazee 17, Frederike Dijk 19, Yogesh K. Vashist 20, Giulia M. Cavestro 21, Peter Hegyi 22, Federico Canzian 17
16 Toxicogenomics Unit, Center for Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic 17 German Cancer Research Center (DKFZ), Heidelberg, Germany 18 Pancreatic and Digestive Endocrine Surgery Group, University of Padua, Padua, Italy 19 Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands 20 Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany 21 Vita Salute San Raffaele and Istituto di Ricovero e Cura a Universita Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milan, Italy 22 Institute for Translational Medicine, University of Pecs, Pecs, Hungary
Introduction: Telomere deregulation is a hallmark of cancer. Telomere length in normal tissues such as in leucocytes (LTL) has been shown to be a risk marker for several cancer types. For pancreatic ductal adenocarcinoma there is a lack of consensus on whether risk is associated with long or short telomeres, partially because LTL measurement is very sensitive to sample handling and other confounders such as age, chemotherapy and the epidemiologic design of the study. Aims: To overcome these difficulties and to determine if LTL is associated with PDAC risk, we used genetic determinants of telomere length as proxies of LTL as it has been successfully done for several cancer types. Materials & methods: We analyzed 10 SNPs (ZNF676-rs409627, TERTrs2736100, CTC1-rs3027234, DHX35-rs6028466, PXK-rs6772228, NAF1rs7675998, ZNF208-rs8105767, OBFC1-rs9420907, ACYP2-rs11125529 and TERC-rs10936599) alone and combined in a LTL genetic score in relation to PDAC risk in 2,374 cases and 4,326 controls from the PANDoRA consortium. Results: We identified several new associations, among which the strongest were with the TERT-rs2736100 SNP (OR¼1.54 [95% CI 1.35-1.76] p¼1.54x10-10) and with the NAF1-rs7675998 SNP (OR¼0.80 [95% CI 0.730.88] p¼1.87x10-6, ptrend¼3.27x10-7). Analyzing the LTL score the association with PDAC risk reached genome-wide significance (p¼2.98x10-9 for highest vs. lowest quintile; p¼1.82 x 10-10 as a continuous variable). Conclusion: We here present a novel genome-wide candidate for PDAC risk (TERT-rs2736100), a completely new signal (NAF1-rs7675998) that approaches the genome-wide threshold and we propose short telomeres as strong risk factor for pancreatic cancer that could be used for risk stratification in the general population or in high risk individuals.
1
Department of Biology, University of Pisa, Pisa, Italy Pancreas Unit, Department of Digestive Diseases, Sant'OrsolaMalpighi Hospital, Bologna, Italy 3 Department of Surgery, Unit of Experimental Surgical Pathology, University Hospital of Pisa, Pisa, Italy 4 Digestive and Liver Disease Unit, S. Andrea Hospital, 'Sapienza' University of Rome, Rome, Italy 5 Department of Digestive Tract, Diseases, Medical University of Lodz, Lodz, Poland 6 Department of Gastroenterology and Institute for Digestive Research, Lithuanian University of Health Sciences, Kaunas, Lithuania 7 Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany 8 Department Molecular Biology of Cancer, Institute of Experimental Medicine, Academy of Sciences, Prague, Czech Republic 9 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany 10 University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom 11 Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom 12 Division of Gastroenterology and Research Laboratory, IRCCS Scientific Institute and Regional General Hospital Casa Sollievo de, Italy 13 National Institute for Health Research Liverpool Pancreas Biomedical Research Unit, University of Liverpool, Liverpool, United Kingdom 14 Oncology Department, ASL1 Massa Carrara, Massa Carrara, Italy 15 ARC-Net Applied Research on Cancer Centre, University and Hospital Trust of Verona, Verona, Italy 2
Abstract ID: 1928. The impact of pancreatic cancer cell exosomes on the phenotype of pancreatic cancer cells Stuart Robinson 1, Derek Mann 2, Richard Charnley 1, Jelena Mann 2, Steve White 1 1 2
HPB Surgery, Freeman Hospital, United Kingdom Fibrosis Research Group, Newcastle University, United Kingdom
Introduction: Exosomes measure up to 100nm in size and play key roles in cell-to-cell communication. They are particularly rich sources of miRNA and are a means by which one cell can impact on the phenotype of neighbouring cells. PSC’s are a key stromal component in pancreatic cancer. Aims: To characterise PSC exosomes and their impact on pancreatic cancer cell phenotype. Materials & methods: Exosomes were isolated from conditioned media of PSC’s. Their miRNA cargo was identified using the nanostring system.MiaPACA2 and PANC1 cells were exposed to exosomes in 2D and 3D culture. Results: The top 15 miRNA’s identified in exosomes were implicated in a variety of cancer associated KEGG pathways e.g. proteoglycans in cancer (p<0.0001), pancreatic cancer (p<0.0001), p53 signalling (p<0.0001), pathways in cancer (p<0.0001) involving over 620 genes. MiaPACA2 cells treated with exosomes demonstrate a 27% reduction in proliferation (p<0.05). This wasn’t replicated in PANC1 cells. MiaPACA2 cells do not form spheroids in hanging drop culture however in the presence of exosomes do
Introduction: FOLFIRINOX chemotherapy has become standard upfront treatment in patients with advanced pancreatic ductal adenocarcinoma (PDAC). However, only one third of the patients show clinical benefit and biomarkers to select these patients are warranted. Due to their high stability in plasma, circulating microRNAs (miRNAs) have been proposed as minimally-invasive biomarkers. Aims: Our aim is to identify blood-based miRNAs as predictive and monitoring biomarkers in patients with PDAC. Patients & methods: Patients with locally advanced and metastatic PDAC receiving first-line FOLFIRINOX (n¼54) were prospectively enrolled. Patients were classified as 'progressive' or 'non-progressive', based on time to progression (cut-off of 6.4 months). MiRNAs were isolated from plasma collected before and after 5-6 cycles of FOLFIRINOX treatment. Differentially expressed miRNAs were identified in a discovery cohort using a microarray panel. To analyze their value as monitoring biomarkers, candidate miRNAs were evaluated in a validation cohort by RT-PCR in extracellular vesicles of 16 non-progressive patients. Results: MiR-29a emerged as a potential biomarker in both analyses. MiR-29a was significantly upregulated (2$36-fold change, p<0$0024) in extracellular vesicles after five cycles of FOLFIRINOX in patients without tumor progression. Interestingly, the expression of miR-29a in extracellular vesicles was significantly higher than circulating free miR-29a expression (p<0$0001). In addition, three miRNAs were considered to be normalising miRNAs of which miR-93 showed the most stable expression. Conclusion: Upregulation of miR-29a in extracellular vesicles can monitor the progression of PDAC in patients treated with FOLFIRINOX. This underlines the opportunity to further explore the clinical utility of miRNAs as biomarkers to select the optimal treatment strategy.
Abstract ID: 1915. The contribution of Lymphotoxin from PanINs to pancreatic tumor development Gitta Maria Wanner-Seleznik 1, Theresia Reding 1, Conny Waschkies 1, Anurag Gupta 1, Daniela Lenggenhager 2, Mathias Heikenwalder 3, Rolf Graf 1 1 Swiss HPB Center, Visceral & Transplantation Surgery, University Hospital Zurich, Switzerland 2 Institute of Pathology, University Hospital Zurich, Switzerland 3 Institute for Virology, Helmholtz-Centre Munich, German Cancer Center (DKFZ) Heidelberg, Germany
Introduction: Pancreatic inflammation is a well-known risk factor for pancreatic ductal adenocarcinoma (PDAC) development. Still, little is known about the cellular and molecular mechanisms how inflammation promotes pre-malignant lesions and tumor progression. We have previously shown that patients suffering from chronic pancreatitis or pancreatic cancer show increased expression of lymphotoxin (LT) in the pancreas. Furthermore, in mice LT overexpression in the exocrine pancreas leads to pancreatitis (chronic, autoimmune). Aims: To assess the role of LT-mediated inflammation in pancreatic carcinogenesis. Materials & methods: We established a mouse model by intercrossing p48+/Cre;Kras+/G12D (KC) mice to transgenic mice overexpressing LT in pancreas (Tg(Ela1-Lta,b); p48+/CreTg+; KrasG12Dflox/+) (LTKC). To evaluate tumor development, we introduced a deletion in the TP53 tumor suppressor gene (KPC; LTKPC). Immunohistochemistry and RT-PCR were used to describe the inflammatory signature. In KPC and LTKPC animals tumor growth was assessed by MRI, furthermore tumors were compared
S21
histologically and biochemically focusing mostly on the distribution of immune cells and formation of tertiary lymphoid organs (TLOs). Results: LT overexpression dramatically accelerated the development of pre-malignant lesions in KC animals. 8 week-old LTKC mice already showed extensive PanIN lesions, which are normally observed in 16-weekold KC animals. LTKPC animals in the survival analysis succumbed to tumors significantly earlier than KPC group. As hypothesized LT overexpression contributed to the formation of TLOs in the pancreatic tumors. Conclusion: We conclude that LT not only accelerated PanIN lesions, but also tumor growth. Moreover, LT overexpression led to changes in tumor microenvironment, which suggests that TLO formation may have a role in pancreatic cancer.
Abstract ID: 1917. Parkin mediated Mitophagy in Acute Pancreatitis Preshit Ravindra Wagh 1, Matthias Sendler 1, Ujwal Mukund Mahajan 2, Frank Ulrich Weiss 1, Markus Lerch 1, Julia Mayerle 2 1 Department of Medicine A, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany 2 Medizinische Klinik und Poliklinik II, Klinikum der LMU MünchenGrosshadern, München, Germany
Introduction: AP is associated with premature activation of digestive proteases in the pancreas resulting in cell death. Previously it has been reported that mitochondrial dysfunction and impaired autophagy contribute to the pathogenesis of AP. Except for their main role in energy production, mitochondria are also implicated in fundamental cellular processes, including ion homeostasis, lipid metabolism, and initiation of apoptotic cell death. However, the inter-relationship between mitochondrial dysfunction and autophagy with regard to cell damage in AP remains elusive. Aims: Investigate the role of E3-ubiquitin-ligase PARK2 (Parkin) mediated Mitophagy in AP. Materials & methods: Mitophagy was studied in parkin-/- and C57Bl/6 mice upon induction of mild AP (caerulein model) and severe AP (l-arginine model). Protease activation, cell death and mitochondrial membrane potential (DJm) was investigated in isolated acini stimulated with supramaximal CCK. Results: Induction of mitophagy in AP can be seen by accumulation of PINK-1 and parkin in the mitochondrial subcellular fraction. Parkin -/animals develop pancreatitis in a miId AP with a restitution ad integrum at 24hr; in a severe AP parkin-/- increases the extent of pancreatic necrosis at 72 hrs in parkin-/- animals. In acinar cells of parkin-/- mice CCK significantly decreased DJm and increased the cell death rate. Conclusion: Parkin dependent mitophagy seems to have an important impact on cell death regulation. Parkin-mediated mitophagy plays a significant role in the regeneration of the pancreas in a mild AP and its absence aggravates severe AP, lack of parkin is at least in parts responsible for necrosis in AP and in acinar cells.
Abstract ID: 1925. TLR2 and TLR4 predict favourable prognosis in early pancreatic cancer €nen 3, Caj €m 2, Harri Mustonen 3, Hanna Seppa Mira Lanki 1, Jaana Hagstro Haglund 1 1 Department of Surgery, Helsinki University Hospital, Research Programs Unit, Translational Cancer Biology, University of Helsinki, Finland 2 Department of Pathology and Oral Pathology, Helsinki University Hospital, Research Programs Unit, University of Helsinki, Finland 3 Department of Surgery, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
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Abstracts / Pancreatology 17 (2017) S1eS142
Introduction: Toll-like receptors (TLRs) play an essential role in our innate immune system and are a point of interest in contemporary cancer research. So far TLRs have shown promising prognostic value in adenocarcinomas of the mouth, colon and ovaries, but the role of TLRs in pancreatic ductal adenocarcinoma (PDAC) is yet to be explored. Aims: We set out to investigate whether TLR expression could be used for prognostic evaluation in PDAC as well. Patients & methods: Our study comprised of 154 stage I-III PDAC patients surgically treated at Helsinki University Hospital between 2000 and 2011. Patients receiving neoadjuvant therapy were excluded from the study. We used tissue microarrays and immunohistochemistry to assess the expression of TLR2 and TLR4 in PDAC tissue, and we matched staining results against clinicopathological parameters using Fischer’s test. For survival analysis we used the Kaplan-Meier method and log-rank test, and the Cox regression proportional hazard model for univariate and multivariate analyses. Results: High TLR2 expression was observed in 51 (34%) and high TLR4 in 50 (33%) patients. Overall neither marker showed correlation with patient mortality. However, multivariate analysis showed that high TLR2 expression predicted lower death risk when tumor size was less than 30mm (HR¼0.32; p¼0.009; 95% CI 0.13-0.75), and that high TLR4 expression predicted lower death risk in patients with lymph node negative disease (HR¼0.21; p¼0.006; 95% CI 0.07-0.65). Conclusion: We found high TLR2 and TLR4 expression to be independent factors of better prognosis in PDAC patients with early disease.
Abstract ID: 1926. Genetic determinants of telomere length and risk of pancreatic cancer: a PANDoRA study Daniele Campa 1, Martina Matarazzi 1, Raffaele Pezzilli 2, Ugo Boggi 3, Gabriele Capurso 4, Renata Talar-Wojnarowska 5, Juozas Kupcinskas 6, Thilo Hackert 7, Pavel Vodicka 8, Hermann Brenner 9, Kay-Tee Khaw 10, Timothy J. Key 11, Stefano Landi 1, Cosmeri Rizzato 1, Francesca Tavano 12, Manuel Gentiluomo 1, Eithne Costello 13, Andrea Mambrini 14, Rita T. Lawlor 15, Pavel Soucek 16, Rudolf Kaaks 17, Anna Caterina Milanetto 18, Ofure Obazee 17, Frederike Dijk 19, Yogesh K. Vashist 20, Giulia M. Cavestro 21, Peter Hegyi 22, Federico Canzian 17
16 Toxicogenomics Unit, Center for Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic 17 German Cancer Research Center (DKFZ), Heidelberg, Germany 18 Pancreatic and Digestive Endocrine Surgery Group, University of Padua, Padua, Italy 19 Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands 20 Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany 21 Vita Salute San Raffaele and Istituto di Ricovero e Cura a Universita Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milan, Italy 22 Institute for Translational Medicine, University of Pecs, Pecs, Hungary
Introduction: Telomere deregulation is a hallmark of cancer. Telomere length in normal tissues such as in leucocytes (LTL) has been shown to be a risk marker for several cancer types. For pancreatic ductal adenocarcinoma there is a lack of consensus on whether risk is associated with long or short telomeres, partially because LTL measurement is very sensitive to sample handling and other confounders such as age, chemotherapy and the epidemiologic design of the study. Aims: To overcome these difficulties and to determine if LTL is associated with PDAC risk, we used genetic determinants of telomere length as proxies of LTL as it has been successfully done for several cancer types. Materials & methods: We analyzed 10 SNPs (ZNF676-rs409627, TERTrs2736100, CTC1-rs3027234, DHX35-rs6028466, PXK-rs6772228, NAF1rs7675998, ZNF208-rs8105767, OBFC1-rs9420907, ACYP2-rs11125529 and TERC-rs10936599) alone and combined in a LTL genetic score in relation to PDAC risk in 2,374 cases and 4,326 controls from the PANDoRA consortium. Results: We identified several new associations, among which the strongest were with the TERT-rs2736100 SNP (OR¼1.54 [95% CI 1.35-1.76] p¼1.54x10-10) and with the NAF1-rs7675998 SNP (OR¼0.80 [95% CI 0.730.88] p¼1.87x10-6, ptrend¼3.27x10-7). Analyzing the LTL score the association with PDAC risk reached genome-wide significance (p¼2.98x10-9 for highest vs. lowest quintile; p¼1.82 x 10-10 as a continuous variable). Conclusion: We here present a novel genome-wide candidate for PDAC risk (TERT-rs2736100), a completely new signal (NAF1-rs7675998) that approaches the genome-wide threshold and we propose short telomeres as strong risk factor for pancreatic cancer that could be used for risk stratification in the general population or in high risk individuals.
1
Department of Biology, University of Pisa, Pisa, Italy Pancreas Unit, Department of Digestive Diseases, Sant'OrsolaMalpighi Hospital, Bologna, Italy 3 Department of Surgery, Unit of Experimental Surgical Pathology, University Hospital of Pisa, Pisa, Italy 4 Digestive and Liver Disease Unit, S. Andrea Hospital, 'Sapienza' University of Rome, Rome, Italy 5 Department of Digestive Tract, Diseases, Medical University of Lodz, Lodz, Poland 6 Department of Gastroenterology and Institute for Digestive Research, Lithuanian University of Health Sciences, Kaunas, Lithuania 7 Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany 8 Department Molecular Biology of Cancer, Institute of Experimental Medicine, Academy of Sciences, Prague, Czech Republic 9 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany 10 University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom 11 Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom 12 Division of Gastroenterology and Research Laboratory, IRCCS Scientific Institute and Regional General Hospital Casa Sollievo de, Italy 13 National Institute for Health Research Liverpool Pancreas Biomedical Research Unit, University of Liverpool, Liverpool, United Kingdom 14 Oncology Department, ASL1 Massa Carrara, Massa Carrara, Italy 15 ARC-Net Applied Research on Cancer Centre, University and Hospital Trust of Verona, Verona, Italy 2
Abstract ID: 1928. The impact of pancreatic cancer cell exosomes on the phenotype of pancreatic cancer cells Stuart Robinson 1, Derek Mann 2, Richard Charnley 1, Jelena Mann 2, Steve White 1 1 2
HPB Surgery, Freeman Hospital, United Kingdom Fibrosis Research Group, Newcastle University, United Kingdom
Introduction: Exosomes measure up to 100nm in size and play key roles in cell-to-cell communication. They are particularly rich sources of miRNA and are a means by which one cell can impact on the phenotype of neighbouring cells. PSC’s are a key stromal component in pancreatic cancer. Aims: To characterise PSC exosomes and their impact on pancreatic cancer cell phenotype. Materials & methods: Exosomes were isolated from conditioned media of PSC’s. Their miRNA cargo was identified using the nanostring system.MiaPACA2 and PANC1 cells were exposed to exosomes in 2D and 3D culture. Results: The top 15 miRNA’s identified in exosomes were implicated in a variety of cancer associated KEGG pathways e.g. proteoglycans in cancer (p<0.0001), pancreatic cancer (p<0.0001), p53 signalling (p<0.0001), pathways in cancer (p<0.0001) involving over 620 genes. MiaPACA2 cells treated with exosomes demonstrate a 27% reduction in proliferation (p<0.05). This wasn’t replicated in PANC1 cells. MiaPACA2 cells do not form spheroids in hanging drop culture however in the presence of exosomes do