Dissertations / Theses on the topic 'Pancreatic ductal cancer'
To see the other types of publications on this topic, follow the link: Pancreatic ductal cancer.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Pancreatic ductal cancer.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Jacobetz, Michael. "Optimizing drug delivery in pancreatic ductal adenocarcinoma." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609438.
2
Cardenas, Alex. "Sphingosine-1-Phosphate in Pancreatic Ductal Adenocarcinoma." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/306974.
Abstract:
Pancreatic ductal adenocarcinoma is an extremely lethal cancer that is difficult to treat. A better understanding of the biology of pancreatic ductal cancer will help to develop targeted therapies that may improve clinical outcomes. Recently, the lipid signaling molecule sphingosine-1-phosphate (S1P) has emerged as a driver of malignant behavior in many types of cancer. Its role in pancreatic cancer remains unknown. Pancreatic cancer cells express high levels of the S1P receptor known as S1PR1, which is the receptor most important for mediating growth and migration through S1P signaling. In addition, the subcellular expression of the sphingosine kinases is altered in pancreatic cancer cells, which may contribute to their malignant behavior. Exogenous S1P increases pancreatic cancer cell migration, while inhibition of S1P signaling decreases the metabolic activity of pancreatic cancer cells as well as their ability to invade and migrate. Taken together, these results demonstrate the importance of S1P signaling in maintaining malignant behavior in pancreatic cancer cells. In addition, inhibition of S1P signaling represents a potential therapeutic target in pancreatic ductal cancer.
3
Kawesha, Anthony. "Prognostic molecular markers in resected ductal pancreatic carcinoma." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7596/.
Abstract:
Previous studies of molecular prognostic markers following resection for exocrine pancreatic cancer have produced conflicting results. The aim of this study was to undertake a comprehensive analysis of potentially useful markers in a large multicentre patient population and compare these markers with standard pathological prognostic variables. Formalin fixed, paraffin-embedded specimens of pancreatic ductal adenocarcinoma were analysed from 157 patients (100 men and 57 women with a median [range] age of 60 [33-77] years) who had undergone pancreatectomy. Immunhistochemistry was used to detect expression of p16\(^{INK4}\), p53, p21\(^{WAF1}\), cyclin D1, c-erbB-2 and c-erbB-3. In a selected number of p53 positive and negative staining cases, mutational analysis was undertaken using DNA obtained from microdissected specimens. Mutations in codons 12 and 13 of the K-ras oncogene were detected by SSCP and sequencing following DNA extraction and amplification by PCR. The median [range] survival post-resection was 12.5 [3-83] months. Abnormalities of p16\(^{INK4}\), p53, p21\(^{WAF1}\), cyclin D1, c-erbB-2 and c-erbB-3 expression were found in 87%, 41%, 75%, 72%, 33% and 57% of cases, respectively. There was no significant correlation between expression of any of these markers and patient survival. K-ras mutations were found in 73 (75%) out of 97% cases with amplifiable DNA. The presence of K-ras mutation alone did not correlate with survival, but there were significant differences in survival according to the type of K-ras mutation (p=0.0007). Reduced survival was found in patients with GaT, cGT and GcT K-ras mutations compared to GtT, aGT and GaC mutations. In conclusion survival was associated with the type of K-ras mutation but not the expression of p16\(^{INK4}\), p53, p21\(^{WAF1}\), cyclinD1, c-erbB-2 and c-erbB3.
4
Naidoo, Kalnisha. "Molecular mechanisms of lymphatic invasion in pancreatic ductal adenocarcinoma." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8606.
Abstract:
Pancreatic Ductal Adenocarcinoma (PDAC) is one of the five leading causes of cancer-related deaths in the West, and this, largely, is due to metastatic disease. In order to better understand PDAC metastatic spread and identify novel therapeutic targets, we analysed the proteome of primary tumours and matched lymph node (LN) metastases. As frozen specimens of metastatic lesions are scarce, we examined formalin-fixed paraffin-embedded (FFPE) tissues. Whilst such tissue is in routine diagnostic use, the cross-linkages induced by fixation have, in the past, precluded proteomic investigation for research purposes. Recent technological advances have, however, overcome this technical limitation. Using laser capture microdissection (P.A.L.M system), we isolated malignant epithelia from seven FFPE primary PDAC tumours and matched LN metastases. Following dissection, samples were analysed in duplicate using Multidimensional Protein Identification Technology (MudPIT); this resulted in the identification of 1504 proteins, 854 of which were common to all samples analysed. Comparison of the obtained proteins with data from previous proteomics studies on pancreatic tissue, pancreatic juice, serum and urine resulted in a less than 30 % overlap, indicating that our study has expanded the current database of proteins expressed in this malignancy substantially. Statistical analysis further showed that 115/854 proteins (13.5%) were significantly differentially expressed (g-value ≥ 3.8). Two proteins, S100P and 14-3-3 sigma, with highly significant g-values were confirmed to be significantly differentially expressed (S100P: p = 0.05 and 14-3-3 sigma: p < 0.001) 4 in a larger series of 55 cases of matched primary PDAC and LN metastases using immunohistochemistry. We chose to investigate further the roles of S100P in lymphatic invasion in vitro and in vivo. By co-culturing a Panc1 S100P-overexpressing clone (S5L), or a vector control clone (V3L), with human dermal lymphatic endothelial cells (HDLEC), we were able to show that different receptors mediate S5L adhesion to resting and activated HDLEC as opposed to V3L; and that the presence of S5L cells in these co-cultures significantly increased permeability at one (p = 0.02), four (p = 0.002) and eight (p = 0.007) hours post-seeding, and significantly increased translymphatic endothelial migration at 72 hours (p = 0.006). Using the V3L and S5L cell lines, which were transduced to express luciferase, we also created an orthotopic mouse model of PDAC, as well as experimental metastatic mouse models, in CD1 nude mice. These models were used to evaluate the effects of S100P on primary tumour growth, metastasis and site-specific growth. S100P was only found to significantly increase primary tumour growth in this model (n = 10 animals/group), both by bioluminescence (p = 0.002) and tumour weight (p = 0.01). No metastases (spontaneous and/or experimental) were seen however. Thus, this model can be used to evaluate the anti-tumour efficacy of novel therapies to S100P in the future.
5
Kadaba, Raghunandan. "Desmoplastic stromal cells modulate tumour cell behaviour in pancreatic cancer." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8825.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is characterised by an intense desmoplastic stromal response that can comprise 60 to 80% of tumour volume and has been implicated to be a factor in promoting tumour invasiveness and the poor prognosis associated with this cancer type. It is now well established that pancreatic stellate cells, which are vitamin A storing cells found in the periacinar spaces of the stroma in the normal gland, are primarily responsible for this desmoplastic reaction. Studying the interaction between stellate cells and cancer cells could provide for a better understanding of the disease process. During the evolution of PDAC, the stromal proportion increases from 4% in the normal gland to up to 80%. We hypothesised that there is an optimal proportion of stellate cells and cancer cells that modulates tumour behaviour and we attempted to dissect out this probable ‘tipping point’ for stromal composition upon cancer cell behaviour using a well-established in vitro organotypic culture model of pancreatic cancer. The cancer cell-stromal cell interaction led to extra-cellular matrix contraction and stiffening; and an increase in cancer cell number. The stromal stellate cells conferred a pro-survival and pro-invasive effect on cancer cells which was most pronounced at a stellate cell proportion of 0.66-0.83. The expression of key molecules involved in EMT and metastasis such as E-Cadherin and β-catenin showed a reduction and this was found to be most significant again at a stellate cell proportion of 0.66-0.83. Stellate cells altered the genetic profile of cancer cells leading to differential expression of genes involved in key cellular pathways such as cell-cycle and proliferation, cell movement and death, cell-cell signalling, and inflammatory response. qRT-PCR confirmed the differential expression of the top differentially expressed genes and protein validation by immunofluorescence staining using PIGR as a candidate molecule confirmed the experimental findings in human PDAC specimens. This study demonstrates that the progressive accumulation of desmoplastic stromal cells has a tumour progressive (pro-survival, pro-invasive) effect on cancer cells in addition to stiffening (contraction) of the extracellular matrix (maximum effect when the stromal cell proportion is 60-80%). This is mediated through a number of signalling cascades and molecular targets. Dampening this tumour-promoting interaction between cancer and stromal cells by ‘multi-targeting’ agents may allow traditional chemo- and/or radiotherapy to be effective.
6
Mohammad, Jiyan Mageed. "Therapeutic Potential of Piperlongumine for Pancreatic Ductal Adenocarcinoma." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/31347.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies because it is often diagnosed at a late disease stage and has a poor response rate to currently available treatments. Therefore, it is critical to develop new therapeutic approaches that will enhance the efficacy and reduce the toxicity of currently used therapies. Here we aimed to evaluate the therapeutic potential and mechanisms of action for piperlongumine (PL), an alkaloid from long pepper, in PDAC models. We postulated that PL causes PDAC cell death through oxidative stress and complements the therapeutic efficacy of chemotherapeutic agents in PDAC cells. First, we determined that PL is one of the most abundant alkaloids with antitumor properties in the long pepper plant. We also showed PL in combination with gemcitabine, a chemotherapy agent used to treat advanced pancreatic cancer, reduced tumor weight and volume compared to vehicle-control and individual treatments. Further, biochemical analysis, including RNA sequencing and immunohistochemistry, suggested that the antitumor activity of PL was associated with decreased cell proliferation, induction of cell cycle arrest, and oxidative stress-induced cell death. Moreover, we identified that c-Jun N-terminal kinase (JNK) inhibition blocks PL-induced cell death, translocation of Nrf2, and transcriptional activation of HMOX1 in PDAC. Finally, high-throughput drug and CRISPR screenings identified potential targets that could be used in combination with PL to treat PDAC cells. Collectively, our data suggests that cell cycle regulators in combination with PL might be an effective approach to combat pancreatic cancer.NIH
7
Puleo, Francesco. "Pancreatic ductal adenocarcinoma: From biomarkers discovery to personalized treatment." Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/271618.
Abstract:
En 2016, environ 53 070 patients ont reçu un diagnostic d'adénocarcinome canalaire pancréatique (PDA) aux États-Unis et la plupart d'entre eux mourront de leur maladie dans les 5 ans. Le registre belge du cancer rapporte une incidence estimée à 1200 nouveaux cas par an. La survie globale à 5 ans pour toutes stades confondus a marginalement augmenté au cours des 50 dernières années, passant de 2 à 6%, malgré l'imagerie, les soins périopératoires et l'amélioration des techniques chirurgicales.La chirurgie reste la seule chance de guérison, cependant, seulement 10-15% des patients nouvellement diagnostiqués sont jugés éligibles pour une chirurgie. Même s'il existe peu d'autres modalités de traitement efficaces qui puissent considérablement prolonger la survie globale, la plupart des patients finiront par mourir de métastases au foie, au poumon et / ou au péritoine, les sites de propagation les plus courants. Les patients, les cliniciens et les chercheurs restent frustrés par le manqué d’outils thérapeutiques et des nouvelles stratégies sont nécessaires pour comprendre et mieux prendre en charge cette maladie.Le terme «cancer» engendre un sentiment de peur et colère, en particulier quand on est confronté au diagnostic dévastateur de cancer du pancréas. En plus, une réaction commune est de personnifier le cancer comme une entité maléfique qui doit être combattue pour sauver la vie du patient. Les armes pour cette bataille comprennent le scalpel d'un chirurgien, la chimiothérapie, la radiothérapie, les thérapies ciblées, les immunothérapies, les approches holistiques et la foi religieuse. Mais nous avons trop souvent oublié ou sous-estimé la contribution de la recherche translationnelle pour la médecine de précision, pour mieux adapter les thérapies et éviter les toxicités inutiles.Dans un sens biologique, qu'est-ce qu'un cancer du pancréas ou un cancer? Le cancer est une maladie génétique, soumise à un phénomène évolutif avec ses propres règles, contraintes et caractéristiques prévisibles qui mènent finalement à un phénotype unique.La stratégie "one size fits all" dans la PDA a souvent échoué dans les essais de nouveaux médicaments dans une population non sélectionnée.Cette thèse est une contribution modeste et authentique à une approche plus personnalisée du PDA, de l'acquisition tissulaire, à l'analyse de biomarqueurs tissulaires, à une analyse moléculaire plus profonde afin de mieux comprendre cette maladie mortelle et de proposer l'intégration de biomarqueurs dans le developpement d’etudes cliniques guides par les analyses moléculaires.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
8
Chan, Derek Steven Hung Che. "Tumoral immune privilege in a murine model of pancreatic ductal adenocarcinoma." Thesis, University of Cambridge, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709503.
9
Cook, Natalie. "The Notch pathway is a therapeutic target in pancreatic ductal adenocarcinoma." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609962.
10
Roshan, Moniri Mani. "Pancreatic ductal-derived mesenchymal stem cells : their distribution, characterization and cytotoxic effect on pancreatic cancer cells." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43529.
Abstract:
Mesenchymal stem cells (MSCs) have attracted significant attention in cancer research as a result of their accessibility, tumor-oriented homing capacity, and the feasibility of auto-transplantation. This study detected the sensitivity of pancreatic cancer cell lines (PCCs) to pancreatic-derived, engineered MSCs under different culture conditions. Pancreatic ductal tissue was extracted from adult human pancreas. MSCs were derived and expanded ex-vivo and verified to fulfil criteria for human MSCs according to the guidelines of the International Society for Cellular Therapy. MSCs were analyzed for distribution and migratory capacity to the site of pancreas and PCCs in in vivo and in vitro models, and found to have homing capacity to the pancreas and towards PCCs (MSCs were attracted to all PCCs compared to normal human A1F8 cells and they displayed significant attraction to the media obtained from cancer cells compared to normal media (p<0.05)). PCCs (BXPC3, ASPC1, Panc-1, TRM6 and HP62) were analyzed by FACS for TNF-α Related Apoptosis Inducing Ligand (TRAIL) receptors. MSCs engineered with non-secreting TRAIL (MSCnsTRAIL) and secreting TRAIL (MSCstTRAIL) and PTEN (MSCPTEN) were used for both direct and indirect co-cultures. TRAIL/PTEN expression was assessed by both ELISA and western blot analysis; higher molecular weight was observed in the MSCnsTRAIL (56kDA) compared with MSCstTRAIL (26kDa). The TRAIL content of supernanatats from MSCstTRAIL was significantly higher than MSCnsTRAIL (p<0.05). PTEN-RFP fusion protein showed a higher molecular weight of 74 kDa in comparison with endogenous PTEN (47 kDa). A real time detection of MSCs cytotoxicity on PCCs displayed proportional cancer cell death to the ratio of conditioned media used from MSCnsTRAIL, MSCstTRAIL, and MSCPTEN. Naive MSCs exhibit intrinsic cytotoxic effect on pancreatic cancer cells and this effect was potentiated by TRAIL/PTEN-engineering. This study provides a practical platform for the development of MSC-based therapy for pancreatic cancer.
11
Ene-Obong, Abasi E. "Immune cell infiltration and interaction with stellate cells in pancreatic ductal adenocarcinoma." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8305.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is a disease with very poor prognosis amongst all pancreatico-biliary cancers. PDAC is characterised by a pronounced desmoplastic stroma which upon depletion has been associated with immune cell mediated tumour clearance. In situ analyses of various immune cell markers in the stromal compartments may provide a lucid picture of immune cell migration to the tumour epithelia. Automated, unbiased, high throughput imaging and analysis of specifically designed tissue microarrays, from surgically resected tissue samples of PDAC, advanced PDAC, and other pancreatico-biliary diseases; stained for distinct immune cell markers was carried out in the juxtatumoural stroma and the panstromal compartments. Prognostic significance was determined with X-Tile software. In vitro and in vivo assays were undertaken to outline the possible mechanisms. Immune cell infiltration to PDAC was higher than infiltration to other pancreatico-biliary diseases with the exception of CD8+ T cells. While CD4+, CD68+ and myeloperoxidase+ cells could infiltrate the juxtatumoural stroma of PDAC; CD3+, CD8+, Foxp3+ and CD20+ cells could not in the early stage PDAC patients tissue analysed and also in an independent validation cohort of advanced stage PDAC patients. Survival analyses demonstrated pro-survival effects of having high CD8+ densities. CD8+ T cells could only infiltrate the juxtatumoural compartment of KPC mice after stromal collapse resulting from targeting stellate cells with All-trans Retinoic Acid. 17 In vitro migration assays demonstrated increased CD8+ T cell migration towards activated pancreatic stellate cells compared to quiescent pancreatic stellate cells and appeared to be dependent on CXCL12. T cells are hindered from migrating to the juxtatumoural compartment by activated pancreatic stellate cells as a result of an increase in CXCL12 secretion. Rendering activated pancreatic stellate cells quiescent results in a reduction of CXCL12 secretion which may allow CD8+ T cells to migrate to the tumours and perform cytotoxic functions.
12
Morita, Toshihiro. "CXCR4 in tumor epithelial cells mediates desmoplastic reaction in pancreatic ductal adenocarcinoma." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/264657.
Abstract:
京都大学新制・課程博士
博士(医学)
甲第23376号
医博第4745号
新制||医||1051(附属図書館)
京都大学大学院医学研究科医学専攻
(主査)教授 中山 健夫, 教授 佐藤 俊哉, 教授 平井 豊博
学位規則第4条第1項該当
Doctor of Medical Science
Kyoto University
DFAM
13
Balmaña, Esteban Meritxell. "Pancreatic cancer markers based on aberrant glycosylation of serum proteins." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/392636.
Abstract:
Cancer is one of the leading causes of death worldwide. Pancreatic ductal adenocarcinoma (PDAC) is characterized by high intrinsic aggressiveness and late diagnosis, causing poor prognosis and resulting in the lowest five-year survival rate among all cancers. Nowadays, there is no biomarker for PDAC diagnosis approved. The survival rate of cancer patients increases when they are diagnosed in the early stages of the pathology; and for this reason, the research of new biomarkers is of great interest.
Tumour cells present aberrant glycosylation on their cell surface and also in the secreted glycoconjugates. Hence, a strategy for new tumour biomarker discovery is based on the identification of specific glycoforms.
This work has explored the glycosylation of two serum glycoproteins, the alpha-1-acid glycoprotein (AGP) and the ceruloplasmin (CP). The glycosylation of the epithelial mucins MUC1 and MUC5AC in healthy and PDAC tissues has also been analysed.El càncer és una de les principals causes de mort. L’adenocarcinoma ductal pancreàtic (PDAC) es caracteritza per una alta agressivitat i un diagnòstic tardà, causant un pronòstic desolador i resultant en el càncer amb la taxa relativa de supervivència als cinc anys menor. Actualment no es disposa d’un biomarcador per al diagnòstic del PDAC.La supervivència dels pacients augmenta quan són diagnosticats en els estadis inicials; per aquest motiu, la recerca de nous marcadors és de gran importància. Les cèl·lules tumorals presenten una glicosilació aberrant en la seva superfície cel·lular i també en els glicoconjugats que secreten. Per tant, una estratègia per al descobriment de nous biomarcadors es basa en la identificació de glicoformes específiques. Aquesta tesi ha explorat la glicosilació de dues glicoproteïnes del sèrum, la alfa-1-glicoproteïna àcida i la ceruloplasmina. També s’ha analitzat la glicosilació de les mucines epitelials MUC1 i MUA5AC en teixits sans i de PDAC.
14
James, Andrew. "Metabolic regulation of the plasma membrane calcium pump in pancreatic ductal adenocarcinoma." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/metabolic-regulation-of-the-plasma-membrane-calcium-pump-in-pancreatic-ductal-adenocarcinoma(0533b59c-e6ee-41fb-ad32-cb4784eadfa1).html.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of cancer with poor prognosis and limited treatment options. Since many patients present with metastatic disease and are thus ineligible for surgical resection, PDAC is almost ubiquitously fatal; new treatment options are therefore needed to combat this disease. A key hallmark of many cancers, including PDAC, is metabolic reprogramming and a shift towards a high glycolytic rate, known as the Warburg effect. This allows cancer cells to generate ATP in the face of hypoxia and to meet the increased metabolic requirements associated with rapid proliferation. We hypothesised that this shift towards glycolytic metabolism has important implications for the regulation of cytosolic Ca2+ ([Ca2+]i) in PDAC, since the plasma membrane Ca2+ ATPase (PMCA), which is critical for maintaining low [Ca2+]i and thus cell survival, is dependent on ATP to extrude cytosolic Ca2+. The relative contributions of mitochondrial vs glycolytic ATP in fuelling the PMCA in human PDAC cell lines (PANC-1 and MIA PaCa-2) were therefore assessed. Moreover, the effects of numerous mechanistically distinct metabolic inhibitors on key readouts of cell death, [Ca2+]i and ATP were investigated. Treatment with glycolytic inhibitors induced significant ATP depletion, PMCA inhibition, [Ca2+]i overload and cell death in both PANC-1 and MIA PaCa-2 cells, while mitochondrial inhibitors had no effect. Subsequently, these experiments were repeated on PDAC cells cultured in media formulated to "switch" their highly glycolytic phenotype back to one more reliant on mitochondrial metabolism. Culture in nominal glucose-free media supplemented with either galactose (10 mM) or alpha-ketoisocaproate (KIC, 2 mM) resulted in a switch in metabolism in MIA PaCa-2 cells, where proliferation rate and glycolysis were significantly decreased, and in the case of cells cultured in KIC, oxidative phosphorylation rate was preserved (assessed using Seahorse XF technology). Following culture of MIA PaCa-2 cells in either galactose or KIC, glycolytic inhibition failed to recapitulate the profound ATP depletion, PMCA inhibition and [Ca2+]i overload observed in glucose-cultured MIA PaCa-2 cells. These data demonstrate that in PDAC cells exhibiting a high rate of glycolysis, glycolytically-derived ATP is important for fuelling [Ca2+]i homeostasis and thus is critical for survival. Finally, using a cell surface biotinylation assay, the keyglycolytic enzymes LDHA, PFKP, GAPDH, PFKFB3 and PKM2 were all found to associate with the plasma membrane in MIA PaCa-2 cells, possibly in a tyrosine phosphorylation-dependent manner. To investigate whether the dynamic membrane-association of glycolytic enzymes provides a privileged supply of ATP to the PMCA in PDAC, the effects of tyrosine kinase inhibitors was assessed on PMCA activity. However, while these inhibited PMCA activity, this occurred without accompanying global ATP depletion. These data indicate that glycolytic ATP is critical for the regulation of [Ca2+]i by the PMCA in PDAC, and that the glycolytic regulation of the PMCA may be an important therapeutic locus. However, further research is required to determine whether membrane-bound glycolytic enzymes regulate its activity.
15
Johnson, Natalie Georgette. "The stellate cancer-associated fibroblast in pancreatic ductal adenocarcinoma : its role in chemoresistance." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/23991.
Abstract:
Introduction: The tumour microenvironment has been found to contribute to cancer survival and progression, and more specifically, the stromal microenvironment has been implicated in the drug resistant nature of cancers such as pancreatic cancer. This microenvironment consists of fibroblasts, pericytes, endothelial cells and the extracellular matrix, with the stellate cancer-associated fibroblast (CAF) being the most predominant cell type present. The aim of this study was to investigate the role of the cancer associated fibroblast in tumourigenesis in Pancreatic Ductal Adenocarcinoma (PDA) with specific reference to the mechanisms involved in chemoresistance via the stellate cancer associated fibroblast. Methods: I investigated the molecular pathogenesis of PDA assessing DNA copy number alterations (CNA) in selection of clinically relevant PDA cell lines (PANC-1, MiaPaCa-2, ASPC-1, SU86.86, HPAC, HS776T, PL5 and PL45), seven primary resected, non immortalised samples (PF3, PF7, PF8, PF9, PF16, PF18 and PF20) and an immortalised stellate cell line using array comparative genomic hybridization (aCGH). All cultures and cell lines were then screened in order to determine their sensitivity to currently used therapeutic compounds. Analysis was done using R software and Graph Pad Prism 5. Results: The non-immortalised stellate CAFs and formalin fixed paraffin embedded stromal fibroblast samples showed no homozygous genomic CNAs. The stellate cancer associated fibroblasts both primary and immortalised appear more responsive to the chemotherapeutic drugs in the compound library compared to the PDA cell lines. Conclusions: This study suggests the absence of homozygous deletions that may lead to a change in phenotype in the stellate CAF. However, the presence of heterozygous deletions and epigenetic changes has not yet been excluded. Further experiments such as micro RNA and epigenetic studies, such as SNP arrays, may identify the presence of aberrations that have aetiological significance in carcinogenesis even if they do not result in CNVs. This higher sensitivity of the stellate CAF to the drugs in the chemotherapy library may favour them as potential targets for management of this hard to street subtype of disease.
16
Bell, Leanne Katherine. "Evaluation of tumour perfusion and fibrosis in mouse models of pancreatic ductal adenocarcinoma, using MRI." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/265615.
Abstract:
Pancreatic Ductal Adenocarcinoma (PDA) is one of the most lethal solid malignancies primarily because it is staunchly resistant to conventional cytotoxic chemotherapies. Xenograft models are typically not sophisticated enough to reproduce the complex pathophysiology of the clinical disease. This is the main reason why treatments that have shown promise in preclinical mouse models have not translated into improvements in median survival in the clinic. Genetically engineered KPC mice develop PDA in situ which recapitulates the genetic, molecular and pathophysiological features of human PDA. Spontaneous KPC tumours are also chemoresistant and this mouse model therefore provides an ideal platform from which to study the biology of PDA. Recent evidence suggests that poor perfusion and extensive fibrosis may prevent the delivery of cytotoxic agents to neoplastic PDA cells and are therefore at least in part responsible for the chemoresistance demonstrated by human PDA tumours and spontaneous KPC tumours. In this thesis we use non-invasive Magnetic Resonance Imaging techniques (Dynamic ContrastEnhanced (DCE-) MRI, Magnetisation Transfer Imaging (MTI)) and SHG microscopy to evaluate the perfusion properties and fibrosis of three different mouse models of PDA: spontaneous KPC tumours, allografts initiated by transplantation of pancreatic tumour cells derived from a KPC tumour, and allografts initiated by co-transplantation of these cells with pancreatic stellate cells (fibrotic allografts). Using DCE-MRI and MTI we showed that the perfusion of spontaneous KPC tumours and fibrotic allografts decreases with increasing tumour volume while the tumour macromolecular content increases with increasing tumour volume. This is in contrast to the viable portion of non-fibrotic allografts which have a low macromolecular content and exhibit sustained moderate perfusion irrespective of tumour volume. Ex viva SHG microscopy clearly showed differences in the type, distribution and magnitude of fibrosis in these models. Using MTI, we showed a differential between spontaneous and transplanted tumours, but not between fibrotic and non-fibrotic allografts. We subsequently investigated the ability of MTI to detect treatment-induced depletion of the stroma in spontaneous KPC tumours, to assess its possible application as a non-invasive biomarker for treatment response in the clinic. However, we were unable to detect such depletion by MTI, although ex viva SHG microscopy confirmed that it did occur. In summary, our results contribute to the body of know_ledge on the biology of PDA and strengthen the evidence that early detection of PDA would be required to improve the chances of effective drug delivery to PDA tumours.
17
Burdyga, Alex. "Control of cAMP signalling in the cellular migration of pancreatic ductal adenocarcinoma." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/12081/.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is characterised by a very high mortality rate and is the 4th most common cause of cancer death (Siegel et al., 2012). The disease initially develops asymptomatically, and at the time of diagnosis patients usually have multiple metastases (Rhim et al., 2012). It would therefore be highly desirable to develop treatments which specifically impede the ability of PDAC cells to metastasise by interfering with the cellular processes responsible for efficient cellular migration. Intracellular signalling cascades, which utilise various signalling proteins, ultimately lead to the appropriate cell coordination and enable efficient cellular motility. One such signalling pathway that participates in the regulation of migration is controlled by the second messenger cyclic adenosine monophosphate (cAMP) (Howe, 2004). Several effectors of cAMP have been found which include protein kinase A (PKA) (Tasken & Aandahl, 2004), exchange factors activated by cAMP (EPAC) (Bos, 2006), and cyclic nucleotide-regulated cation channels (Biel, 2009). PKA has been intimately linked with several cellular processes which contribute towards cell motility. In most cases, the various specific effects of PKA signalling require selective targeting of the kinase into microdomains through interaction with A-kinase-anchoring proteins (AKAPs) (Pidoux & Tasken, 2010). Other cAMP effectors such as EPAC have defined roles in controlling various aspects of migration, such as cellular adhesion to the extracellular matrix (Bos, 2005). The effect of modulating cAMP signalling on the rate of migration has been investigated in several cancer types. Interestingly the results obtained were rather varied; both inhibition and stimulation of migration was observed (Chen et al., 2008; Baljinnyam et al., 2009; Grandoch et al., 2009; Shaikh et al., 2012). However, the effect of cAMP, and its effectors, on the rate of migration has not been investigated in PDAC; this was the main aim of this study. Classical cAMP elevating agents such as forskolin and 3-Isobutyl-1-methylxanthine (IBMX), as well as the cAMP analogue 8-Bromoadenosine 3’5’-cyclic monophosphate (8Br-cAMP), were found to inhibit migration of the PANC-1 cells. The role of cAMP signalling was further supported by the results of experiments utilising cAMP FRET sensors, which were imaged in live single cells. Further characterisation of cAMP effects in 4 other diverse PDAC cell lines yielded similar results, indicating that the mechanism of inhibition was common to all PDAC cell types tested. PANC-1 cell invasion was also inhibited by cAMP elevation. I went on to investigate events such as cell ruffling and focal adhesion assembly, which are processes closely associated with cellular motility. Dual transfection with a cAMP sensor and GFP tagged paxillin revealed a relationship between cAMP elevation and the loss of paxillin from focal adhesions, which was quickly reversible upon cAMP returning back to basal levels. Using a similar approach, peripheral cell ruffling was found to be inhibited by intracellular cAMP elevation. These results indicated that the inhibition of migration upon cAMP elevation was likely to occur as a result of immediate signalling events (and not due to cAMP-dependent changes in gene expression). The final part of the project concentrated on the individual contribution of the downstream effectors of cAMP, with particular emphasis on selective PKA and EPAC modulation. Utilising both PKA and EPAC sensors, I determined the appropriate concentrations of N6-benzoyl-cAMP (6Bnz) and 8-pCPT-2’OMe-cAMP (8pCPT) required to achieve selective PKA and EPAC activation respectively. Interestingly, I found that the two effectors had opposing actions; EPAC activation was found to induce migration, while PKA was found to suppress migration. Further investigation utilised a potent and selective PKA inhibitor peptide (PKI), which upon expression was found to prevent inhibition of ruffling, paxillin loss from focal adhesions, and inhibition of migration in response to cAMP elevation. Furthermore, it was found that suppression of basal PKA activity had a tendency to induce migration. I also utilised a cell permeable peptide (st-Ht31) which inhibits PKA interaction with AKAPs, thus effectively reducing its function by uncoupling the kinase from its specific signalling microdomains. The resulting effect was found to be a large potentiation of PANC-1 migration, which further highlighted the importance of PKA activity in the control of migration.
18
Alrawashdeh, Wasfi. "Molecular characterization of perineural invasion in pancreatic ductal adenocarcinoma : proteomic analysis and in vitro modelling." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8699.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, and the 5th most common cause of cancer death in the UK. One of the peculiarities of this malignancy is its ability to invade nerves, a process called perineural invasion (PNI). PNI is found in almost 100% of PDAC, and is associated with poor prognosis, tumour recurrence and generation of pain. However, the molecular bases of PNI remain largely unknown. We investigated the molecular alterations underlying the neuro-epithelial interactions in PNI using one and two dimensional liquid chromatography – mass spectrometry (1D and 2D LC-MS) of laser microdissected PNI and non-PNI cancer from formalin fixed, paraffin embedded PDAC tissues. We also performed 1D LC-MS analysis of invaded and non-invaded nerves from the same cases. In addition, we developed an in vitro model of PNI using a co-culture system comprising PC12 cells, a rat pheochromocytoma cell line, as the neuronal element and PDAC cell lines. The overall proteomic profiles of PNI and non-PNI cancer appeared largely similar; of very few deregulated proteins, we have validated the up-regulation of antiapoptotic protein Olfactomedin 4 in PNI cancer using immunohistochemistry. In contrast, nerve samples demonstrated widespread molecular alterations characteristic of neuronal plasticity upon invasion by cancer cells. Immunohistochemistry confirmed the up-regulation of VGF in nerves from PDAC and chronic pancreatitis (CP) specimens compared to normal pancreas, as well as in invaded compared to non-invaded nerves in PDAC tissues. Furthermore, VGF expression strongly correlated with pain in CP; similar analysis in PDAC cases is still pending. Using the in vitro co-culture model, several PDAC cell lines were able to induce PC12 cells neuronal plasticity including survival, neurite extension as well as VGF expression, recapitulating thus the changes observed in human tissues. PDAC-induced PC12 plasticity was not mediated via NGF, a neurotrophin acting upstream of VGF and thought to be involved in the neuro-epithelial interactions. The induction of VGF expression was shown not to be necessary for PC12 cell survival, however, it contributed to the neurite extension induced by PDAC cell lines. In summary, based on proteomics analysis and in vitro modelling, we show the complex and intricate involvement and crosstalk of both tumoral and neural elements that are activated during perineural invasion in pancreatic cancer.
19
Kersting, Stephan, Johanna Roth, and Alfred Bunk. "Transabdominal Contrast-Enhanced Ultrasonography of Pancreatic Cancer." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-136474.
Abstract:
Since its introduction, contrast-enhanced ultrasonography (CEUS) has significantly extended the value of ultrasonography (US). CEUS can be used to more accurately determine pancreatic lesions compared to conventional US or to characterize lesions already detectable by US. Thus, CEUS can aid in the differential diagnosis of pancreatic tumors. Using US contrast media, it is possible to visually detect microvessels in the majority of pancreatic ductal adenocarcinomas. Thus, the use of quantitatively evaluated transabdominal CEUS can help in the differentiation of patients with mass-forming pancreatitis from patients with pancreatic adenocarcinomas. In neuroendocrine pancreatic tumors, different enhancement patterns can be observed in relation to the tumor mass: larger ones show a rapid early enhancement sometimes combined with necrotic central structures, and smaller ones disclose a capillary-blush enhancement. Pseudocysts, the most widespread cystic lesions of the pancreas, are not vascularized. They do not show any signal in CEUS and remain entirely anechoic in all phases, while true cystic pancreatic tumors usually have vascularized septa and parietal nodules. In summary, CEUS is effective for differentiating solid pancreatic tumors in most cases. CEUS is safe and cost effective and can better discriminate solid from cystic pancreatic lesions, thereby directing further imaging modalitiesDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
20
Jomrich, Gerd, Elisabeth S. Gruber, Daniel Winkler, Marlene Hollenstein, Michael Gnant, Klaus Sahora, and Martin Schindl. "Systemic Immune-Inflammation Index (SII) Predicts Poor Survival in Pancreatic Cancer Patients Undergoing Resection." Springer US, 2019. http://dx.doi.org/10.1007/s11605-019-04187-z.
Abstract:
Background: The systemic immune-inflammation index based on peripheral neutrophil, lymphocyte, and platelet counts has
shown a prognostic impact in several malignancies. The aim of this study was to determine the prognostic role of systemic immune-inflammation index in patients with pancreatic ductal adenocarcinoma undergoing resection.
Methods: Consecutive patients who underwent surgical resection at the department of surgery at the Medical University of Vienna between 1995 and 2014 were included into this study. The systemic immune-inflammation index was calculated by the formula platelet*neutrophil/lymphocyte. Optimal cutoffs were determined using Youden's index. Uni-and multivariate analyses were calculated by the Cox proportional hazard regression model for overall survival.
Results Three hundred twenty-one patients were included in this study. Clinical data was achieved from a prospective patient database. In univariate survival analysis, elevated systemic immune-inflammation index was found to be significantly associated with shortened patients' overall survival (p = 0.007). In multivariate survival analysis, systemic immune-inflammation index
remained an independent prognostic factor for overall survival (p = 0.004). No statistical significance could be found for platelet
to lymphocyte ratio and neutrophil to lymphocyte ratio in multivariate analysis. Furthermore, area under the curve analysis showed a higher prognostic significance for systemic immune-inflammation index, compared to platelet to lymphocyte ratio and neutrophil to lymphocyte ratio.
Conclusion A high systemic immune-inflammation index is an independent, preoperative available prognostic factor in patients with resectable pancreatic ductal adenocarcinoma and is superior to platelet to lymphocyte ratio and neutrophil to lymphocyte ratio for predicting overall survival in pancreatic ductal adenocarcinoma patients.
21
Kasloff, Samantha Beth. "Oncolytic activity of avian influenza virus in human pancreatic ductal adenocarcinoma cell lines." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424131.
Abstract:
Pancreatic Ductal Adenocarcinoma (PDA), the most common form of pancreatic cancer, is among the most lethal forms of cancer due to diagnoses being made at late stages when tumours are no longer resectable and the disease has often metastasized. Chemotherapy and radiation therapy are employed as part of the management of most patients, however in the absence of surgery these treatments are considered only life prolonging rather than life saving. As a result, the 5-year survival rates for PDA are less than 5% and the need for alternative therapies is critical. Oncolytic virotherapy is a branch of cancer therapy that has grown vastly in recent years in terms of scientific advances. This form of cancer therapy uses modified viruses that are specifically targeted to the malignant phenotype yet leave healthy bystander cells largely unharmed. Influenza A viruses have been largely overlooked as agents of oncolytic virotherapy, with only a small number of publications produced over the last two decades. Building on the observation that avian influenza A viruses (IAVs) have a tropism for the pancreas in vivo, the present study was aimed at testing the efficacy of IAV as oncolytic agents to kill human PDA cell lines.
To determine whether human PDA cells could be susceptible to Receptor characterization of the pancreatic cell lines included confirmed the expression of both alpha-2,3 and alpha-2,6-linked glycan receptors required for virus attachment by avian and human-tropic influenza viruses, respectively. Consistent with this finding, pilot experiments demonstrated that PDA cell lines were sensitive to infection by human and avian IAV isolates. Growth kinetic experiments showed that multiple rounds of virus replication were achieved by highly pathogenic viruses but not low pathogenic (LP) viruses. This was attributed to the excessive sensitivity these cells showed for the exogenous trypsin required by these viruses for multiple rounds of infection in vitro, as analyses of viruses at early time points post-infection showed high level RNA replication. To quantitatively determine cell death induced by the different virus isolates in PDA cells following infection, MTT assays were performed and demonstrated a significant induction of cell death at 24 hours post infection, and this was particularly severe in the case of an H7N3 isolate. Analyses of apoptosis induction by Annexin V staining further confirmed these results, and interestingly showed that infection with LP IAVs at early time points post treatment caused higher levels of apoptosis in PDA cells compared to gemcitabine and cisplatin, which are the cornerstone of current therapies for PDA. Even more, IAVs did not induce apoptosis in the non-transformed pancreatic ductal HPDE6 cells at near comparable levels to those observed in the PDA cell lines. A closer examination of the mechanisms through which these high levels of apoptosis were induced by the H7N3 virus revealed that in the BxPC-3 PDA cell line, apoptosis resulted from the engagement of the intrinsic mitochondrial pathway.
To determine whether any experimental isolates showed an enhanced affinity towards glycans frequently associated with the cancerous phenotype, the binding affinities of three LP viruses that showed good ability to induce PDA cell death were assessed by solid-phase binding assay. Two of the viruses, H7N3 and H7N7, showed strong binding preference for cancer-associated antigens SLeX and SLeA, though this affinity is not absolute and is not likely a suitable mechanism to limit tissue tropism.
Finally, using a xenograft model of PDA cell growth in SCID mice, the H7N3 virus was shown to significantly inhibit BxPC-3 tumour growth following a series of intratumoural injection. Taken together, these results suggest that low pathogenic IAVs may prove to be effective for oncolytic virotherapy of PDA, and provide grounds for further studies to develop specific and targeted viruses with the aim of testing their efficacy in clinical contextsL’adenocarcinoma duttale pancreatico (PDA) è la forma più aggressiva e comune di tumore al pancreas. Terapie efficaci nei confronti di altri tipi di tumore hanno mostrato scarsi risultati nel trattamento del PDA; pertanto la necessità di tecniche alternativeè di cruciale importanza. Viroterapia e un trattamento che impiega virus ingegnerizzati geneticamente al fine di infettare ed uccidere selettivamente le cellule tumorali, e negli ultimi sta crescendo molto come campo scientifici. L’osservazione di un tropismo pancreatico del virus influenzale ha guidato il nostro gruppo a testarne l’impiego come agente oncolitico nei confronti dell’adenocarcinoma duttale del pancreas. Sebbene studiato per le influenze stagionali e le pandemie ad esso associate, il virus influenzale non è stato altrettanto investigato per il suo potenziale impiego come agente oncolitico. Lo scopo di questo studio era di testare l'efficacia di IAV come virus oncolitico contro le linee cellulari PDA umane. Diverse linee cellulari di adenocarcinoma pancreatico sono state caratterizzate dal punto di vista recettoriale per valutare la presenza sulla loro superficie di recettori sialici alpha-2,3 o alpha-2,6 in grado di legare i virus influenzale aviari (alpha2-3) o di mammifero (alpha 2-6), e la presenza di tutti e due tipi di ricettori e stato confermato sulla superfice di tutte le linee. Coerentemente con questo risultato, esperimenti pilota hanno dimostrato che linee cellulari PDA erano sensibili alle infezioni da IAV umana e aviaria isolati. Esperimenti di cinetica di crescita hanno mostrato che vari cicli di replicazione del virus sono stati raggiunti da virus altamente patogeni, ma non a bassa patogenicità (LP) virus. Questo è stato attribuito alla sensibilità eccessiva queste cellule hanno mostrato per la tripsina esogeno richiesto da questi virus per più cicli di infezione in vitro, come le analisi di virus in momenti iniziali dopo l'infezione ha mostrato RNA replica di alto livello. Per determinare quantitativamente la morte cellulare indotta dai diversi isolati virali in cellule PDA seguenti infezione, saggi MTT state eseguite e dimostrato una significativa induzione di morte cellulare a 24 ore dopo l'infezione, e questo era particolarmente grave nel caso di un isolato H7N3. Le analisi di induzione dell'apoptosi usando il mercatore annessina V hanno messo in luce come tutti i ceppi virali testati diano livelli di apoptosi più alti rispetto al controllo (Gem+Cisp) in tutte le linee cellulari tumorali impiegate nello studio. In particolare in BXPC-3 (la linea più sensibile tra quelle testate) il ceppo H7N3 A/tukey/Italy/2962/03 ha indotto livelli più alti. In HPDE6, invece si registra una maggiore morte cellulare derivata dal trattamento con i chemoterapici rispetto a quelle portata dall’infezione virale. Il virus influenzale, quindi, mostrava una abilità innata nel causare morte cellulare più efficacemente in linee tumorali rispetto alle cellule sane. Per scoprire il meccanismo tramite cui il cepo H7N3 ha eserito il suo effeto apototico sulle cellule BxPC-3, una valutazione dei citochini indotti dal virus H7N3 ha rivelato che nella linea cellulare BxPC-3 PDA, l’apoptosi veniva indotto dal via mitocondriale intrinseca. Per determinare se i ceppi IAV sperimentali avevano una maggiore affinità intrinsica verso i glicani frequentemente associati con il fenotipo tumorale, le affinità di legame dei tre virus LP che hanno mostrato una buona capacità di indurre la morte delle cellule di PDA sono stati valutati mediante un solid phase binding assay. Due dei virus, H7N3 e H7N7, hanno mostrato una forte preferenza vincolante per gli antigeni tumorali associate Slex e Slea, anche se questa affinità non è assoluto e non è probabilmente un meccanismo adeguato per limitare tropismo tissutale. Sulla base della sua capacità nell’indurre apoptosi il virus H7N3 A/tukey/Italy/2962/03 è stato scelto per vedere la sua capacita antitumorale usando un modello di xenotrapianto di crescita cellulare PDA in topi SCID. Dopo una serie di iniezioni intratumorali, il gruppo trattato con il virus ha avuto una crescita tumorale molto ridotta rispetto al gruppo controllo. Presi insieme, questi risultati suggeriscono che i virus influenzali di bassa patogenicita possono rivelarsi efficaci per viroterapia oncolytic di PDA, e giustificano ulteriori studi per lo sviluppo di virus specifici e modificati, con l'obiettivo di testare la loro efficacia in contesti clinici
22
Kondratska-Klymenko, Kateryna. "Role of calcium-permeable channels in pancreatic ductal adenocarcinoma resistance to chemotherapy." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10099/document.
Abstract:
L'adénocarcinome pancréatique (PDAC) est la forme la plus fréquente de néoplasme de cet organe puisqu’il représente environ 90% de toutes les tumeurs pancréatiques et constitue l'une des principales causes de décès par cancer chez l’Homme. Le taux de survie à 5 ans n’est que de 6%. L'une des raisons à cela est que, au début du développement du cancer du pancréas, il n'y a pas de symptômes, et donc la majorité des cas sont diagnostiqués à des stades tardifs métastatiques ou invasifs pour lesquels une intervention chirurgicale n’est plus possible. Il a été montré que les cellules du cancer du pancréas présentent plusieurs mutations génétiques qui conduisent à la prolifération incontrôlée des cellules, ainsi qu’à l'évasion de l'apoptose. Les changements de concentration du Ca2+ cytosolique jouent un rôle central dans de nombreux processus cellulaires fondamentaux, et la perturbation des mécanismes de régulation de l'homéostasie du Ca2+ conduit à une grande variété de pathologies graves, dont le cancer. C’est notamment le cas pour les canaux calciques de type SOC, qui régulent une variété de processus cellulaires dépendants du calcium. Cependant, bien que le rôle du Ca2+ et des canaux calciques soit bien établi dans de nombreuses voies de signalisation de différents types cellulaires, les informations sur le rôle des canaux calciques dans le PDAC sont limitées. Donc, l'identification de la nature moléculaire ainsi que des fonctions des canaux calciques revêt une grande importance dans ces cellules car elle pourrait à termes fournir de nouvelles approches relatives au traitement du cancer du pancréas par le ciblage des processus dépendants du calciumPancreatic ductal adenocarcinoma (PDAC) representing the most prevalent pancreatic neoplasm accounting for about 90% of all pancreatic tumors, is one of the leading causes of cancer death in men and women. The current five-year relative survival rate is about 6% . One of the reasons of this is that early stage pancreatic cancer usually has no symptoms and thus the majority of cases are diagnosed at the late metastatic or invasive stages which are not suitable for surgery. Pancreatic cancer cells have been shown to exhibit a number of genetic mutations leading to uncontrolled cell proliferation, as well as evasion of programmed cell death (apoptosis). Changes in the cytosolic free Ca2+ concentration, play a central role in many fundamental cellular processes and disturbance of the Ca2+ homeostasis regulatory mechanisms leads to a vast variety of severe pathologies, including cancer. Among these, store-operated calcium channels (SOCs) have been shown to regulate a variety of calcium dependent cellular processes altered in different cancers. However, although the role of Ca2+ and calcium-permeable channels is well established in many signaling pathways in a variety of cell types, the information of the role of calcium-permeable channels in PDAC cells is limited. Therefore, identification of the molecular nature as well as functions of calcium-permeable channels in these cells is of great importance as it can reveal novel approaches for treating pancreatic cancer through targeting calcium-dependent processes
23
Kersting, Stephan, Johanna Roth, and Alfred Bunk. "Transabdominal Contrast-Enhanced Ultrasonography of Pancreatic Cancer." Karger, 2011. https://tud.qucosa.de/id/qucosa%3A27707.
Abstract:
Since its introduction, contrast-enhanced ultrasonography (CEUS) has significantly extended the value of ultrasonography (US). CEUS can be used to more accurately determine pancreatic lesions compared to conventional US or to characterize lesions already detectable by US. Thus, CEUS can aid in the differential diagnosis of pancreatic tumors. Using US contrast media, it is possible to visually detect microvessels in the majority of pancreatic ductal adenocarcinomas. Thus, the use of quantitatively evaluated transabdominal CEUS can help in the differentiation of patients with mass-forming pancreatitis from patients with pancreatic adenocarcinomas. In neuroendocrine pancreatic tumors, different enhancement patterns can be observed in relation to the tumor mass: larger ones show a rapid early enhancement sometimes combined with necrotic central structures, and smaller ones disclose a capillary-blush enhancement. Pseudocysts, the most widespread cystic lesions of the pancreas, are not vascularized. They do not show any signal in CEUS and remain entirely anechoic in all phases, while true cystic pancreatic tumors usually have vascularized septa and parietal nodules. In summary, CEUS is effective for differentiating solid pancreatic tumors in most cases. CEUS is safe and cost effective and can better discriminate solid from cystic pancreatic lesions, thereby directing further imaging modalities.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
24
Neuzillet, Cindy. "Inter- and intra-tumoral heterogeneity and dynamics of cancer-associated fibroblasts in pancreatic ductal adenocarcinoma." Thesis, Sorbonne Paris Cité, 2018. https://theses.md.univ-paris-diderot.fr/NEUZILLET_Cindy_2_va_20181015.zip.
Abstract:
Les fibroblastes associés au cancer (cancer-associated fibroblasts, CAF) sont des chefs d’orchestre du microenvironnement tumoral (stroma) de l'adénocarcinome canalaire pancréatique (AP). L'hétérogénéité du stroma pourrait expliquer les rôles physiopathologiques non univoques (pro- vs. anti-tumoraux) du stroma de l’AP. Nous avons émis l'hypothèse qu'il existe plusieurs sous-types de CAFs dans l’AP qui contribuent à l'hétérogénéité du stroma notamment par leurs interactions avec les cellules tumorales et immunitaires.Ce projet s’est décomposé en trois parties :- Dans la première partie, en appliquant des analyses bioinformatiques étendues et un large éventail de tests in vitro à des cultures primaires de CAF dérivées d’AP, nous avons démontré la diversité biologique des CAFs pancréatiques humains; nous avons identifié quatre sous-types de CAFs avec des caractéristiques moléculaires et fonctionnelles spécifiques (signatures liées à la matrice et au système immunitaire, expression de vimentine et d’actine musculaire lisse, activité proliférative), et nous avons montré que l'hétérogénéité des CAFs avait un impact sur les interactions avec les cellules tumorales dans des modèles organotypiques.- Dans la deuxième partie, nous avons montré que les sous-types de CAFs et leurs combinaisons étaient associés à des caractéristiques phénotypiques distinctes des tumeurs (sous-type moléculaire et grade, abondance et activité du stroma, infiltrats immunitaires, angiogenèse) et à la survie des patients, in silico dans les données publiques de l'ICGC et par immunohistochimie dans une cohorte de patients bien caractérisés.- Dans la troisième partie, nous avons montré que plusieurs sous-types de CAFs peuvent émerger in vitro (expériences avec des milieux conditionnés) et in vivo (xénogreffes orthotopiques) à partir des cellules stellaires pancréatiques suite à leurs interactions dynamiques avec les cellules tumorales, par un processus d'«empreinte», modulé ensuite par d'autres facteurs et/ou partenaires cellulaires dans le microenvironnement tumoral; par ailleurs, nous avons confirmé dans un contexte murin nos résultats sur l'association entre l'expression des marqueurs de sous-types de CAFs et le phénotype immunitaire observé dans les tumeurs humaines. Cette classification unique des CAFs pancréatiques humains (pCAFassigner) démontre l'hétérogénéité phénotypique inter- et intra-tumorale des CAFs dans l’AP. Nos résultats ouvrent la voie à de futures études fonctionnelles et au développement de thérapies ciblant spécifiquement certaines sous-populations de CAFs dans l’APCancer-associated fibroblasts (CAF) are orchestrators of the pancreatic ductal adenocarcinoma (PDAC) microenvironment. Stromal heterogeneity may explain differential pathophysiological roles of the stroma (pro- vs. anti-tumoral) in PDAC. We hypothesised that multiple CAF subtypes exist in PDAC that contribute to stromal heterogeneity through interactions with cancer and immune cells. This project comprised three parts:- In Part 1, by applying extended bioinformatics analysis and a wide range of in vitro assays to human PDAC-derived primary CAF cultures, we demonstrated the biological diversity of human pancreatic CAFs; we identified four CAF subtypes (A-D) with specific molecular and functional features (matrix- and immune-related signatures, vimentin and ?-smooth muscle actin expression, proliferation rate), and we showed that CAF heterogeneity had an impact on the interactions with cancer cells in mini-organotypic models.- In Part 2, we showed that the combination of CAF sub-populations was associated with distinct phenotypic characteristics of the tumours (tumour molecular subtype and grade, stromal abundance and activity, immune infiltrates, angiogenesis) and patient survival, in silico in the ICGC dataset and by immunohistochemistry in an extensively characterised patient cohort.- In Part 3, we showed that several CAF subtypes may emerge in vitro (conditioned media experiments) and in vivo (orthotopic xenografts) from the dynamic interactions of pancreatic stellate cells with cancer cells, through an “imprinting” process, and may be further modulated by other factors and/or cellular partners in the tumour microenvironment; in addition, we confirmed in a murine setting our findings about the association between CAF subtype marker expression and immune phenotype observed in human tumours.This unique classification for pancreatic CAFs (pCAFassigner) demonstrates the inter- and intra-tumoral phenotypic heterogeneity of CAFs in human PDAC. Our results provide a framework for future functional studies and pave the way for the development of therapies targeting specific CAF sub-populations in PDAC
25
Sutaria, Dhruvitkumar S. "INVESTIGATION OF DIFFERENTIALLY EXPRESSED NONCODING RNAS IN PANCREATIC DUCTAL ADENOCARCINOMA." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480550158159039.
26
Ogawa, Satoshi. "SETDB1 Inhibits p53-Mediated Apoptosis and is Required for Formation of Pancreatic Ductal Adenocarcinomas in Mice." Kyoto University, 2020. http://hdl.handle.net/2433/259014.
27
Guerrero, Barrado Pedro Enrique. "Altered glycosylation in pancreatic cancer: development of new tumor markers and therapeutic strategies." Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/671007.
Abstract:
Pancreatic Ductal Adenocarcinoma (PDA), the most common pancreatic cancer, remains one of the most lethal tumor types, with extremely low survival rates due to late diagnosis and resistance to standard therapies. Expression of tumor-associated carbohydrate antigens such as SLeX enhances several tumor features like cell migration or metastasis, representing a good source of new therapeutic targets and biomarkers. In this work, it has been studied the effect of the inhibition of the expression of the main genes that code for the enzymes responsible for the final steps of SLeX biosynthesis (the α2,3-sialyltransferases). Silencing of ST3GAL3 and ST3GAL4 in two PDA cell lines led to a significant reduction in SLeX associated with a decrease in cell migration, invasion and adhesion to E-selectin, decreasing PDA metastatic potential. Also, using glycoproteomic techniques, we identified the glycoprotein MFAP4 carrying SLeX as potential PDA biomarker since it is only present in PDA tissue samplesEl adenocarcinoma ductal pancreático o PDA, es el tipo más frecuente de cáncer de páncreas. El PDA es uno de los tumores más letales, con tasas de supervivencia extremadamente bajas, debido principalmente al diagnóstico tardío y su amplia resistencia a las terapias actuales. La expresión de antígenos carbohidratos asociados a tumores como el SLeX potencia varias características tumorales como la migración celular o metástasis, por lo cual representa una buena fuente de nuevas dianas terapéuticas y biomarcadores. En este trabajo, se ha estudiado el efecto de la inhibición de la expresión de los principales genes que codifican para las enzimas responsables de la biosíntesis de SLeX en sus etapas finales (las α2,3-sialiltransferasas). El silenciamiento de ST3GAL3 y ST3GAL4 en dos líneas celulares de PDA produjo a una reducción significativa en los niveles de SLeX. Este descenso se asoció con una disminución en la migración, invasión y adhesión celular a E-selectina, disminuyendo el potencial metastásico del PDA. Además, mediante técnicas glico-proteómicas, pudimos identificar la glicoproteína MFAP4 portadora de SLeX como potencial biomarcador de PDA, ya que esta glicoforma solo fue detectada en la cohorte de muestras de tejido de PDA
28
Lenk, Lennart Terje Niklas [Verfasser]. "Metastasis of Pancreatic Cancer: Influence of the hepatic microenvironment on the growth behavior of pancreatic ductal epithelial cells / Lennart Terje Niklas Lenk." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/114291982X/34.
29
Distler, Marius, Felix Rückert, Maximilian Hunger, Stephan Kersting, Christian Pilarsky, Hans-Detlev Saeger, and Robert Grützmann. "Evaluation of survival in patients after pancreatic head resection for ductal adenocarcinoma." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-127053.
Abstract:
Background: Surgery remains the only curative option for the treatment of pancreatic adenocarcinoma (PDAC). The goal of this study was to investigate the clinical outcome and prognostic factors in patients after resection for ductal adenocarcinoma of the pancreatic head.
Methods: The data from 195 patients who underwent pancreatic head resection for PDAC between 1993 and 2011 in our center were retrospectively analyzed. The prognostic factors for survival after operation were evaluated using multivariate analysis.
Results: The head resection surgeries included 69.7% pylorus-preserving pancreatoduodenectomies (PPPD) and 30.3% standard Kausch-Whipple pancreatoduodenectomies (Whipple). The overall mortality after pancreatoduodenectomy (PD) was 4.1%, and the overall morbidity was 42%. The actuarial 3- and 5-year survival rates were 31.5% (95% CI, 25.04%-39.6%) and 11.86% (95% CI, 7.38%-19.0%), respectively. Univariate analyses demonstrated that elevated CEA (p = 0.002) and elevated CA 19–9 (p = 0.026) levels, tumor grade (p = 0.001) and hard texture of the pancreatic gland (p = 0.017) were significant predictors of a poor survival. However, only CEA >3 ng/ml (p < 0.005) and tumor grade 3 (p = 0.027) were validated as significant predictors of survival in multivariate analysis.
Conclusions: Our results suggest that tumor marker levels and tumor grade are significant predictors of poor survival for patients with pancreatic head cancer. Furthermore, hard texture of the pancreatic gland appears to be associated with poor survival.
30
Martínez, Bosch Neus. "Characterization of Galectin-1 in Pancreatic Cancer: A sweet target for a bitter disease." Doctoral thesis, Universitat Pompeu Fabra, 2011. http://hdl.handle.net/10803/80662.
Abstract:
Pancreatic cancer is nowadays one of the neoplasms with worst prognosis, so research
towards the discovery of new molecular targets for therapy and diagnosis is more than
urgent. In this direction, we have deeply evaluated the role of Galectin-1 (Gal-1) - a
protein that is highly overexpressed in the tumor stroma- in pancreatic tumor progression.
Interestingly, we have found that Gal-1 interacts with tissue plasminogen activator (tPA)
and that this interplay seems to be involved both in pancreatic tumor epithelial cells and
fibroblasts migration, Erk1/2 activation and invasion, suggesting its importance in the
tumor/stroma crosstalk in vitro. We have also focused on the biochemical identification
of tPA/Gal-1 interaction domains. Furthermore, we have studied Gal-1 role in
pancreatic tumor progression in vivo, using murine (xenografts and transgenics) and
zebrafish models. We have found that Gal-1 participates in proliferation, angiogenesis,
stroma formation and necrosis in Ela-1-myc pancreatic tumors, as well as in the acinar to
ductal metaplasia. Importantly, these effects result in an overall significant increase in the
survival of Ela-1-myc mice with reduced Gal-1 levels. We have also analyzed Gal-1
role in mouse embryonic pancreatic development, finding interesting parallelisms with
tumors. Finally, the molecular mechanisms involved in Gal-1 driving tumor pancreatic
progression have been addressed through a transcriptome analysis. All together, our
data support Gal-1 as a new molecular target to fight against pancreatic cancer.Avui en dia, el càncer de pàncrees representa un dels tumors amb més elevats índex de mortalitat, per la qual cosa la recerca dirigida a la identificació de molècules per teràpia i diagnosi són més que necessàries. Amb aquest objectiu, hem avaluat el paper que juga Galectina-1 (Gal-1) - una proteïna altament sobreexpressada en l’estroma tumoral- en la progressió tumoral pancreàtica. Hem trobat que Gal-1 interactua amb l’activador tissular del plasminògen (tPA), participant en la migració, l’activació de Erk1/2 i la invasió, tant en cèl4lules tumorals pancreàtiques com en fibroblasts in vitro, suggerint una importància caudal d’aquesta interacció en la comunicació entre el tumor i l’estroma. Així mateix, ens hem centrat en la identificació bioquímica dels dominis d’interacció entre Gal-1 i tPA. A més, el paper de Gal-1 en la progressió tumoral pancreàtica ha estat adreçat in vivo, utilitzant models murins (xenografts i transgènics) i el peix zebra. Així doncs hem trobat que Gal-1 participa en la proliferació, angiogènesi, formació de l’estroma i la necrosi dels tumors pancreàtics dels ratolins Ela- 1-myc, així com en la metaplasia acinar-ductal. De forma significativa, aquests efectes es tradueixen en un increment important en la supervivència dels ratolins Ela-1-myc amb nivells reduïts de Gal-1. Hem també analitzat el paper que juga Gal-1 en el desenvolupament pancreàtic embrionari murí, trobant paral4lelismes interessants amb els tumors. Finalment, hem volgut ocupar-nos dels mecanismes moleculars involucrats en els efectes produïts per Gal-1 durant la progressió tumoral pancreàtica mitjançant microarrays. Les nostres dades presenten Gal-1 com una nova diana terapèutica per lluitar contra el càncer de pàncrees.
31
Pérez, Garay Marta. "Role of alpha 2,3-sialyltransferases ST3Gal III and ST3Gal IV in pancreatic ductal adenocarcinoma." Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/7644.
Abstract:
Este trabajo demuestra que los genes que codifican para los enzimas beta-galactosido alfa-2,3-sialiltransferasa 3 (ST3Gal III), y en menor medida beta-galactosido alfa-2,3-sialiltransferasa 4 (ST3Gal IV), están directamente implicados en etapas clave de la progresión tumoral como la adhesión, la migración y la formación de metástasis en las líneas de adenocarcinoma pancreático humano Capan-1 y MDAPanc-28. También, que las Especies Reactivas del Oxígeno (ROS) generadas durante los procesos de proliferación y diferenciación celular o debido a estímulos oxidantes externos, desempeñan un importante papel en el control de la síntesis de ST3Gal III y SLex, y por lo tanto en la regulación del fenotipo metastático. Además, junto al papel pro-adhesivo de la E-Selectina, este trabajo ha descrito efectos prometastáticos adicionales para esta molécula como inductora de la migración y de la secreción de VEGF a través de un mecanismo E-Selectina-SLex dependiente.This work shows that genes that codifying for the enzymes beta-galactoside alpha-2,3-sialyltransferase 3 (ST3Gal III), and in a lower extent beta-galactoside alpha-2,3-sialyltransferase 4 (ST3Gal IV) , are directly implicated in key steps of tumour progression such as adhesion, migration and metastasis formation in the pancreatic adenocarcinoma cell lines Capan-1 and MDAPanc-28. Moreover, Reactive Oxygen Species (ROS) generated in these cell lines during cell proliferation-differentiation processes or by external oxidant stimuli, play a role in the control of ST3Gal III and SLex levels and in the acquisition of a more aggressive phenotype. And, together with the pro-adhesive role of E-Selectin for circulating cells, this work uncovers sE-Selectin dependent migration and VEGF secretion through a SLex depending mechanism, supporting additional pro-metastatic effects for sE-Selectin-SLex interaction.
32
Macchini, Marina <1982>. "Relationship Between Chronic Inflammation and Cancer: Interleukin-1β Overexpression Induces Pancreatic Ductal Adenocarcinoma in Oncogenic Kras Mice." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7316/2/Tesi_Marina_Online.pdf.
Abstract:
Chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC) development. Polymorphisms in the pro-inflammatory cytokine gene interleukin 1β (IL-1β), as well as high IL-1β or low IL-1 receptor antagonist (IL-1RA) serum levels, are associated to worse prognosis in PDAC patients. To characterize the role of IL-1β in pancreatic tumorigenesis, we generated a transgenic mouse model bearing KRASG12D mutation combined to chronic inflammation induced by pancreatic overexpression of human IL-1β (KC-IL-1β). We found that IL-1β overexpression induced PDAC onset in 6 out of 13 KRASG12D bearing animals (46%), with a median overall survival of 10.5 months, compared to only 1 out of 13 mice carrying KRASG12D mutation alone (KC)(7.7% p= 0.02).
In primary pancreatic KRASG12D organoid cultures, IL-1β exposure increased the number of spheroids and induced gene expression changes consistent with epithelial to mesenchymal transition (EMT), as shown by increased expression of vimentin, Zeb1, Snail. All these changes were counteracted using a recombinant human IL-1receptor antagonist (IL1-RA). Consistently, immuno-histochemical analysis confirmed that in KC-IL-1β tumor epithelial cells and metastasis were strongly positive for vimentin.
The relevance of these findings was confirmed in human PDAC, showing higher IL-1 receptor I (IL1-RI) and vimentin expression in tumor tissue compared with adjacent normal pancreas.
Regarding the mechanism involved in EMT activation, IL-1β exposure was found to induce an up-regulation of ribosome biogenesis rate, with consequent down-regulation of p53 protein expression which has been shown to be responsible for EMT changes.
The finding that IL-1β/IL1-RI inflammatory pathway stimulates acinar cell proliferation and promotes EMT provides the rationale for a therapeutic strategy based on IL-1β receptor blockade to counteract inflammation-induced pancreatic tumorigenesis
33
Macchini, Marina <1982>. "Relationship Between Chronic Inflammation and Cancer: Interleukin-1β Overexpression Induces Pancreatic Ductal Adenocarcinoma in Oncogenic Kras Mice." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7316/.
Abstract:
Chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC) development. Polymorphisms in the pro-inflammatory cytokine gene interleukin 1β (IL-1β), as well as high IL-1β or low IL-1 receptor antagonist (IL-1RA) serum levels, are associated to worse prognosis in PDAC patients. To characterize the role of IL-1β in pancreatic tumorigenesis, we generated a transgenic mouse model bearing KRASG12D mutation combined to chronic inflammation induced by pancreatic overexpression of human IL-1β (KC-IL-1β). We found that IL-1β overexpression induced PDAC onset in 6 out of 13 KRASG12D bearing animals (46%), with a median overall survival of 10.5 months, compared to only 1 out of 13 mice carrying KRASG12D mutation alone (KC)(7.7% p= 0.02).
In primary pancreatic KRASG12D organoid cultures, IL-1β exposure increased the number of spheroids and induced gene expression changes consistent with epithelial to mesenchymal transition (EMT), as shown by increased expression of vimentin, Zeb1, Snail. All these changes were counteracted using a recombinant human IL-1receptor antagonist (IL1-RA). Consistently, immuno-histochemical analysis confirmed that in KC-IL-1β tumor epithelial cells and metastasis were strongly positive for vimentin.
The relevance of these findings was confirmed in human PDAC, showing higher IL-1 receptor I (IL1-RI) and vimentin expression in tumor tissue compared with adjacent normal pancreas.
Regarding the mechanism involved in EMT activation, IL-1β exposure was found to induce an up-regulation of ribosome biogenesis rate, with consequent down-regulation of p53 protein expression which has been shown to be responsible for EMT changes.
The finding that IL-1β/IL1-RI inflammatory pathway stimulates acinar cell proliferation and promotes EMT provides the rationale for a therapeutic strategy based on IL-1β receptor blockade to counteract inflammation-induced pancreatic tumorigenesis
34
Audero, Madelaine. "Acidic tumor microenvironment and Ca2+ signaling interplay in Pancreatic Ductal Adenocarcinoma (PDAC) progression." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS105.
Abstract:
L'adénocarcinome canalaire pancréatique (PDAC) est une maladie mortelle caractérisée par un micro-environnement tumoral (TME) extrêmement acide (˂pHe 6,5) qui joue un rôle important dans son début et sa progression. Dans ce contexte, les canaux ioniques perméables au Ca2+ représentent de bons candidats cibles en raison de leur capacité à intégrer des signaux provenant de la TME. Les canaux Ca2+ sont en effet des capteurs de pH capables d'intégrer les signaux de la TME pour activer les voies intracellulaires en aval liées à la progression du PDAC. Bien que les rôles de l'acidose tumorale et de la signalisation du Ca2+ dans la progression du cancer soient bien établis, l'hypothèse d'une TME acide utilisant la signalisation du Ca2+ comme voie préférentielle pour soutenir la progression tumorale n'a pas encore été suffisamment explorée.Mon travail de doctorat visait à étudier les changements phénotypiques et génétiques des cellules PDAC lors d'un stress acide au cours des différentes étapes de sélection et à évaluer comment l'acidose tumorale module les signaux Ca2+ et les phénotypes dans les lignées cellulaires PDAC, avec un accent particulier sur les oscillations Ca2+ et Store-Operated Ca2+ entry (SOCE). À cette fin, les cellules PANC-1 et Mia PaCa-2 ont été soumises à une pression acide à court et à long terme et à une récupération à pHe 7,4. Ce dernier traitement visait à imiter les bords du PDAC et l'évasion consécutif des cellules cancéreuses de la tumeur. L'impact de l'acidose a été évalué sur la morphologie cellulaire, la prolifération, l'adhésion, la migration, l'invasion, l'activité des invadopodes et la transition épithélio-mésenchymateuse (TEM) par des tests fonctionnels in vitro et le séquençage de l'ARN, ainsi que sur les signaux Ca2+ intracellulaires avec Fura-2. Nos résultats indiquent qu'un court traitement acide limite la croissance, l'adhésion, l'invasion et la viabilité des cellules PDAC. Au fur et à mesure que le traitement acide progresse, il sélectionne les cellules cancéreuses ayant des capacités de migration et d'invasion accrues induites par l'EMT, ce qui augmente encore leur potentiel métastatique lorsqu'elles sont réexposées à un pHe 7,4. L'analyse RNA-seq des cellules PANC-1 exposées à une acidose de courte durée et récupérées à pHe 7,4 a révélé un recâblage transcriptomique distinct. Il est intéressant de noter que les cellules PANC-1 sont caractérisées par des oscillations Ca2+ plus lentes pendant une exposition à l'acide à court terme par rapport aux cellules de contrôle et par une tendance à la régulation négative d'ORAI1 au niveau de l'ARNm, tandis que l'acidose à long terme et le rétablissement à un pH neutre déterminent le rétablissement d'oscillations Ca2+ rapides et la régulation positive d'ORAI1. Dans tous nos modèles cellulaires, les oscillations du Ca2+ sont dépendantes de SOCE, car le blocage d'ORAI1 par Synta66 et siORAI1 entraîne une altération de l'initiation et du maintien des oscillations du Ca2+. Ces données sont en corrélation avec le SOCE dans les cellules PANC-1, qui est diminuée pendant le traitement acide à court terme, et augmentée dans les cellules sélectionnées pour l'acide avec et sans récupération à pHe 7,4. Enfin, l'entrée de Ca2+ médiée par ORAI1 pourrait être impliquée dans l'activation des cascades de signalisation qui conduisent à l'augmentation de la migration et de l'invasion de tous les modèles cellulaires exposés à un pHe acide, car le traitement par Synta66 et siORAI1 n'ont pas affecté l'invasion et la migration des cellules de contrôle.En conclusion, nos résultats montrent que la sélection induite par l'acide contribue à l'acquisition d'un phénotype plus agressif dans les cellules de PDAC, caractérisé par une augmentation du SOCE, nécessaire à la génération d'oscillations rapides de Ca2+ qui peuvent activer des voies de signalisation Ca2+-dépendantes impliquées dans la progression du PDACPancreatic ductal adenocarcinoma (PDAC) is the most common cancer affecting the pancreas, characterized by an unsatisfactory 5-year survival rate of around 10%, and to date, there are no effective therapeutic options for PDAC. This is in part due to a highly desmoplastic and immunosuppressive microenvironment that contributes to therapeutic failure. Moreover, the PDAC tumor microenvironment is featured by high acidosis (˂ pHe 6.5), a result of the metabolic reprogramming ("Warburg effect"), and hypoxic conditions, which offers important cues for its aggressiveness by selecting cancer cell phenotypes with competitive benefits for PDAC progression. In this context, Ca2+-permeable ion channels are known to regulate several hallmarks of cancer, including in PDAC. Therefore, they represent good target candidates due to their ability to integrate signals from the TME. Ca2+ channels are indeed pH and hypoxia sensors able to transduce TME signals to activate intracellular downstream pathways linked to PDAC progression. Although the roles of tumor acidosis and Ca2+ signaling in cancer progression are well established, the hypothesis of acidic TME employing Ca2+ signaling as a preferential route for sustaining tumor progression has not yet been sufficiently explored.My Ph.D. work aimed to study the phenotypic and genetic changes of PDAC cells upon acidic stress along the different stages of selection and to evaluate how tumor acidosis modulates Ca2+ signals and phenotypes in the PDAC cell lines, with a particular focus on Ca2+ oscillations and Store-Operated Ca2+ entry (SOCE). To this end, PANC-1 and Mia PaCa-2 cells were subjected to short- and long-term acidic pressure and recovery to pHe 7.4. The latter treatment was to mimic PDAC edges and consequent cancer cell escape from the tumor. The impact of acidosis was assessed for cell morphology, proliferation, adhesion, migration, invasion, invadopodia activity, and epithelial-mesenchymal transition (EMT) via functional in vitro assays and RNA sequencing, and for intracellular Ca2+ signals using Fura-2. Our results indicate that short acidic treatment limits the growth, adhesion, invasion, and viability of PDAC cells. As the acid treatment progresses, it selects cancer cells with enhanced migration and invasion abilities induced by EMT, thereby further enhancing their metastatic potential when re-exposed to pHe 7.4. RNA-seq analysis of PANC-1 cells exposed to short-term acidosis and pHe-selected recovered to pHe 7.4 revealed distinct transcriptome rewiring. We noted an enrichment of genes relevant to proliferation, migration, EMT, and invasion in acid-selected cells. Interestingly, PANC-1 cells are characterized by slower Ca2+ oscillations during short-term acid exposure compared to control cells and a tendency of ORAI1 downregulation at mRNA levels, while long-term acidosis and recovery to neutral pHe determine the recovery of fast Ca2+ oscillations and upregulation of ORAI1. In all our cell models, Ca2+ oscillations are SOCE-dependent, as ORAI1 blockade with Synta66 and siORAI1 results in impaired Ca2+ oscillations' initiation and maintenance. These data correlate with SOCE in PANC-1 cells, which is decreased during the short-term acid treatment, and increased in acid-selected cells with and without recovery to pHe 7.4. Finally, ORAI1-mediated Ca2+ entry might be involved in the activation of signaling cascades that lead to the increased migration and invasion of all the cell models exposed to acidic pHe, as Synta66 treatment and siORAI1 didn't affect control cells' invasion and migration.In conclusion, our findings show that acid-induced selection contributes to the acquisition of a more aggressive phenotype in PDAC cells, characterized by upregulation of SOCE, required for the generation of fast Ca2+ oscillations which may trigger Ca2+-dependent signaling pathways involved in PDAC progression
35
Schnipper, Julie. "The impact of the acidic tumor microenvironment on ion channel expression and regulation, in the progression of pancreatic ductal adenocarcinoma." Electronic Thesis or Diss., Amiens, 2022. http://www.theses.fr/2022AMIE0071.
Abstract:
Le canal TRPC1 (pour transient receptor potential canonical 1) est l'un des canaux cationiques non sélectifs les plus impliqués dans plusieurs maladies, y compris la progression du cancer. Les TRPC peuvent être activés par différents stimuli physico-chimiques dont le pH. Par ailleurs, l'une des caractéristiques du cancer représente les variations pH extracellulaire, notamment dans l'adénocarcinome canalaire pancréatique (ACP). Il existe de fortes indications quant à l'agressivité de l'ACP qui est causée par l'interaction entre le microenvironnement acide de la tumeur et la dérégulation des canaux ioniques. Cependant, cette interaction n'a jamais été étudiée. Lors de ce travail, nous avons étudié si TRPC1 ainsi que les fluctuations du pH acide du microenvironnement tumoral régulent la progression de l'ACP et plus particulièrement la prolifération et de migration cellulaires. Nous avons constaté que TRPC1 était surexprimé dans le tissu tumoral pancréatique par rapport au tissu normal, et dans la lignée cellulaire agressive PANC-1, par rapport à une lignée cellulaire de type canalaire, hTERT-HPNE. Pour déterminer si les fluctuations du microenvironnement acide de la tumeur affectent la dérégulation de TRPC1, les cellules PANC-1 ont été incubées dans un milieu présentant un pH de 7,4 ou 6,5 pendant 30 jours, après quoi les cellules ont été récupérées à pH 7,4 pendant 14 jours (7.4 R). L'adaptation acide (6.5) a réduit l'expression de la protéine TRPC1 mais a favorisé sa localisation membranaire par rapport au contrôle (7.4). Dans des conditions de pH 7,4R, les cellules cancéreuses présentaient une expression de TRPC1 exacerbée avec une localisation membranaire élevée, à la fois dans les modèles 2D et 3D. Nous avons constaté que les fluctuations de pH et l'invalidation moléculaire par siARN (KD) de TRPC1 affectaient respectivement la prolifération de PANC-1 dans un modèle 2D et sphéroïde. Dans notre modèle 2D, nous avons montré que TRPC1 KD affectait la progression à travers la phase G0/G1 dans toutes les conditions et la phase S lorsque les cellules sont cultivées dans un milieu pH 7,4, et la phase G2/M dans les conditions pH 6,5 et 7,4 R. En outre, pH 6,5 a amélioré tandis que le KD de TRPC1 a diminué la migration cellulaire. De plus, nous avons constaté que TRPC1 interagissait fortement avec PI3K dans des conditions acides, et CaM dans toutes les conditions. Le KD de TRPC1 diminuait à la fois cette interaction et l'activation de AKT et ERK1/2. Enfin, l'entrée basale de Ca2+ a été significativement réduite par le KD de TRPC1 dans les conditions de pH 6,5 et 7,4R. La réduction de la concentration de Ca2+ extracellulaire a entraîné une diminution additionnelle de la prolifération et de la migration des cellules transfectées avec siTRPC1 cultivées à pH 6,5 et 7,4R, mais pas dans des conditions normales de pH 7,4. Collectivement, nos résultats montrent que TRPC1 est régulé positivement dans les tissus et lignées d’ACP. Le microenvironnement acide de la tumeur favorise sa localisation membranaire et son interaction avec PI3K/CaM. Enfin, le Ca2+ transitant par TRPC1 participe à la prolifération et à la migration cellulaires. De plus, nous avons effectué un criblage du profil d'expression des canaux ORAI, de leur partenaire STIM1, d'un canal sodique activé par le voltage (Nav1.6) et d'un canal ionique détectant l'acidité (ASIC1) dans les tissus et lignées d'ACP. Nous avons examiné si le microenvironnement acide affecte la régulation épigénétique des canaux ioniques. Nous avons constaté qu'ORAI3 était régulé positivement dans le tissu ACP par rapport au tissu normal, tandis que STIM1 et NaV1.6 étaient régulés négativement. De plus, ORAI3 était préférentiellement localisé au niveau membranaire dans le tissu tumoral. De plus, nos résultats préliminaires montrent que le microenvironnement acide de la tumeur n'affecte pas les niveaux de méthylation de la région promotrice des gènes codant pour ASIC1 ou TRPC1, mais également du gène SCN8AThe transient receptor potential canonical 1 channel (TRPC1) is one of the most prominent nonselective cation channels involved in several diseases, including cancer progression. TRPCs can be activated by different physio-chemical stimuli of their surroundings, for instance, pH. Another hallmark of cancer is the variable extracellular pH landscape, notably in epithelial cancers such as pancreatic ductal adenocarcinoma (PDAC). PDAC progression and development are linked to the physiology and microenvironment of the exocrine pancreas. There are strong indications that PDAC aggressiveness is caused by the interplay between the tumor acidic microenvironment and ion channel dysregulation. However, this interaction has never been studied before. Here, we investigate if TRPC1 is involved in PDAC progression in the form of proliferation and migration and if the pH fluctuations of the acidic tumor microenvironment affect these processes. We found that TRPC1 was significantly upregulated in PDAC tumor tissue compared to adjacent normal tissue, and in the aggressive PDAC cell line PANC-1, compared to a duct-like cell line, hTERT-HPNE. To investigate if fluctuations of the acidic tumor microenvironment affect TRPC1 dysregulation, PANC-1 cells were incubated in a medium with a pH of 7.4 or 6.5 over 30 days, where after cells were recovered in pH 7.4 for 14 days (7.4R). Acid adaptation (6.5) reduced TRPC1 protein expression but favored its membrane localization compared to the control (7.4). pH recovery treatment (7.4R) resulted in an upregulation of TRPC1 expression with a high membrane localization, both in 2D and 3D models. We found that pH fluctuations and the siRNA-based knock-down (KD) of TRPC1 affected 2D and spheroid PANC-1 proliferation, respectively. In our 2D model, flow cytometry and cell cycle regulating protein immunoblotting showed that TRPC1 KD affected the progression through G0/G1 phase under all conditions and S-phase under control pH 7.4, which shifts to the G2/M phase in pH 6.5 and 7.4R. In addition, pH 6.5 enhanced, and the KD of TRPC1 decreased cell migration, respectively. Furthermore, we found that TRPC1 interacted strongly with PI3K under acidic conditions and CaM under all conditions, and a KD of TRPC1 decreased both this interaction and the activation of AKT and ERK1/2. Finally, basal Ca2+ entry was significantly reduced upon the KD of TRPC1 in pH 6.5 and 7.4R, where the entry was enhanced. The reduction of extracellular Ca2+ concentration resulted in an additional decrease in proliferation and migration of cells transfected with siTRPC1 growing in pH 6.5 and 7.4R, but not in normal pH 7.4 conditions.Collectively, our results show that TRPC1 is upregulated in PDAC tissue and cell lines. The acidic tumor microenvironment favors its plasma membrane localization, and its interaction with PI3K/CaM and Ca2+ entry leads to PDAC cells proliferation and migration. In addition, we performed an expression profile screening of ORAI channels, their partner STIM1, and a voltage-activated sodium channel (Nav1.6), and an acid-sensing ion channel (ASIC1) in PDAC tissues and cell lines, and investigated whether the acidic tumor microenvironment affects epigenetic regulation of ion channel expression. We found that ORAI3 was upregulated in PDAC tissue compared to normal tissue, where STIM1 and NaV1.6 were significantly downregulated. Moreover, ORAI3 was more localized in the plasma membrane in tumor tissue. Acid-adaptation had a differential effect on Ca2+ channel expression. Furthermore, our preliminary results show that the acidic tumor microenvironment does not affect the methylation levels of the ASIC1 or TRPC1 promoter region, but so some extend the SCN8A gene promoter
36
Albert, Colomer Nerea. "Heterogeneity of carcinoma-associated fibroblasts and REV-ERB-induced phenotype molding in pancreatic ductal adenocarcinoma." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/673586.
Abstract:
Tumor-stroma crosstalk is essential for PDAC formation. Therefore, the stroma, and specifically the carcinoma-associated fibroblasts (CAFs), are the target of therapeutic alternatives to treat highly desmoplastic tumors such as PDAC. Lately, many CAFs-targeted therapies have been published. However, some of these strategies have not been completely satisfactory results may be because of the presence of CAFs heterogeneity. Therefore, the objectives of this thesis are to identify specific biomarkers of CAFs subpopulations to describe specific signatures to each one. And, with this information, to develop strategies to reprogram protumoral CAFs towards a less supportive subpopulation. Firstly, we isolated CAFs from human PDAC samples. These CAFs were used to perform in vitro cultures without or with pancreatic tumor cells. The transcriptional analysis of these cultures revealed the presence of two different CAFs signatures: the mono-culture and the co-culture. The first one obtained from the culture of CAFs without tumor cells and the second one from the culture of CAFs with tumor cells. Specifically, mono-cultured CAFs show a myofibroblast-like phenotype, while de co-cultured CAFs present an enrichment in inflammatory processes, proliferation and lipid biosynthesis. In addition, these signatures correlated with others described in different patients’ datasets. Afterwards, we used independent PDAC patients’ datasets to study the prognostic value or our signatures. Our signatures, their signaling pathways or even specific markers of such processes were associated with a prognostic value. In particular, patients with high expression of the mono-cultured CAFs signature, their corresponding pathways or, biomarkers, correlated with a better prognosis. However, patients pathways or, biomarkers, correlated with a better prognosis. However, patients with high expression of co-cultured CAFs signature were associated with a worse prognosis. Secondly, we performed a transcriptomic characterization of all CAFs isolated from human PDAC tumor samples and we defined 3 CAFs subpopulations with different expression patterns and functional features: the myoCAFs, the lipoCAFs, and the ecmCAFs. Result that confirmed the CAFs heterogeneity in PDAC. We also used our different CAFs subtypes to evaluate the effects of the tumorstroma crosstalk by some functional assays. The results suggested that paracrine communication between CAFs and tumor cells, was not able to induce functional changes in tumor cells. However, the transcriptional analysis of CAFs co-cultured with tumor cells, in which there is contact between different cell types, confirmed that the presence of tumor cells induced the expression of activated-fibroblast genes in CAFs. Finally, we evaluated the CAFs’ subtypes biomarkers spatial distribution on human PDAC tissue samples. This validation confirmed the coexistence of different subpopulation of CAFs in the same tumor. And, at the same time, it confirmed the existence 2 main type of PDAC tumors, ones characterized by a high myofibroblast content (aSMAÓ/FAPÔ) and, others with a low myofibroblast content (aSMAÔ/FAPÓ). We could also correlate the distribution of these biomarkers with the tumor histology. Poorly differentiated tumors, without well-defined glandular structure, usually showed a low expression of myofibroblast markers. In this and other previous works haven been described that CAFs undergo transcriptomic and metabolomic modifications in response to tumor signals. Many of these changes are modulated by nuclear receptors and transcription factors. Therefore, in this thesis CAFs were treated with REV-ERB drugs. The REV-ERB is a nuclear receptor that acts as a repressor of many processes up- or downregulated in our CAFs signatures. The intention of this treatment was to modulate CAFs towards a less tumor-supportive state. Specifically, the treatment of CAFs with SR9009, a REV-ERB agonist, caused a dedifferentiation state in CAFs. The dedifferentiation state was characterized by an increased capacity to store intracellular lipids, a reduced lipid metabolism and a reduced expression of the classic fibroblast-activation biomarkers. These events have been described as a properly of pancreatic stellate cells (PSCs), a cell type considered CAFs’ precursors. Thus, this study offers new therapeutic opportunities for PDAC and other highly desmoplastic tumors treatment through modulation of CAFs toward less activated stages.
37
Brandt, Regine, Robert Grützmann, Andrea Bauer, Ralf Jesenofsky, Jörg Ringel, Matthias Löhr, Christian Pilarsky, and Jörg D. Hoheisel. "DNA microarray analysis of pancreatic malignancies." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-136556.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment are needed. Recent advances in human genome research and high-throughput molecular technologies make it possible to cope with the molecular complexity of malignant tumors. With DNA array technology, mRNA expression levels of thousand of genes can be measured simultaneously in a single assay. As several studies using microarrays in PDAC have already been published, this review attempts to compare the published data and therefore to validate the results. In addition, the applied techniques are discussed in the context of pancreatic malignanciesDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
38
Brandt, Regine, Robert Grützmann, Andrea Bauer, Ralf Jesenofsky, Jörg Ringel, Matthias Löhr, Christian Pilarsky, and Jörg D. Hoheisel. "DNA microarray analysis of pancreatic malignancies." Karger, 2004. https://tud.qucosa.de/id/qucosa%3A27711.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment are needed. Recent advances in human genome research and high-throughput molecular technologies make it possible to cope with the molecular complexity of malignant tumors. With DNA array technology, mRNA expression levels of thousand of genes can be measured simultaneously in a single assay. As several studies using microarrays in PDAC have already been published, this review attempts to compare the published data and therefore to validate the results. In addition, the applied techniques are discussed in the context of pancreatic malignancies.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
39
Sawai, Yugo. "Activation-Induced Cytidine Deaminase Contributes to Pancreatic Tumorigenesis by Inducing Tumor-Related Gene Mutations." Kyoto University, 2016. http://hdl.handle.net/2433/215393.
40
Cook, Jenny Anne. "Classical monocytes from patients with pancreatic ductal adenocarcinoma exhibit a significantly altered transcriptome profile compared with healthy volunteers." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/7977.
Abstract:
Pancreatic Ductal Adenocarcinoma (PDAC) affects approximately 8000 people every year in the UK and is the fifth leading cause of cancer related death. At a molecular level PDAC is characterized by a significant immune infiltrate. Tumour-associated macrophages (TAMs) infiltrate the tumour and contribute to a worse prognosis by promoting growth, metastasis and resistance to chemotherapy. TAMs are derived from circulating ‘classical’ CD14++ CD16- monocytes in the peripheral blood. Current work in murine models suggests targeting monocyte recruitment in PDAC can reduce TAM infiltration and disease burden therefore improving survival. This project aims to identify markers specific to monocytes from PDAC patients and to investigate their biological relevance and potential for therapeutic intervention. Gene expression and metabolomics analysis was carried out on classical CD14++ CD16- monocytes from locally advanced PDAC patients and age matched healthy donors. Transcriptomic profiling revealed a significantly altered gene expression profile in classical monocytes from patients and genes with the highest fold change difference were chosen for validation using qPCR. Validated gene targets were investigated further in vitro and large-scale gene expression analysis from pancreatic tumours assessed. The results from my work demonstrate that the gene expression profile of classical monocytes from PDAC patients is significantly different compared to healthy volunteers. Identification and validation of up-regulated genes and their biological relevance may represent a relevant novel novel biomarker or therapeutic strategyies to target monocytes and myeloid recruitment in cancer.
41
Grachan, Jeremy J. "Characterization of Hypoxia-Inducible Lipid Droplet Associated Protein (HILPDA) Dependent Lipid Droplet Abundance in Pancreatic Cancer Tumors Cells." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586437335477715.
42
Göhrig, Andreas. "The role of the axon guidance molecule Slit2 in pancreatic cancer." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2015. http://dx.doi.org/10.18452/17202.
Abstract:
Lokale Invasion und Ausbreitung von Tumorzellen entlang von Nerven und Gefäßen limitieren den Erfolg kurativer Therapien von Patienten mit Pankreaskarzinom (PDAC). Der axon guidance Faktor Slit2 und seine Robo-Rezeptoren steuern die Navigation von Nerven und Gefäßen sowie die Motilität von Epithelzellen. Sie stellen somit attraktive Regulatoren der klinisch bedeutsamen Ausbreitungswege des PDAC dar. Zielsetzung der vorgelegten Arbeit war die Charakterisierung der Expression von Slit2 im PDAC und seiner Funktion für Tumorwachstum und -ausbreitung. Quantitative Analysen belegten eine deutliche Reduktion der Slit2 mRNA Expression in humanen PDAC Proben im Vergleich zu gesundem Gewebe. Zudem korrelierten Slit2 mRNA-Werte unterhalb des Medians mit einer höheren Inzidenz lymphatischer Metastasierung und einem gesteigerten Prozentsatz befallener Lymphknoten. Die Slit2-Rezeptoren Robo1 und 4 wiesen hingegen vergleichbare Immunreaktivität im Tumor und gesundem Gewebe auf, wobei eine differentielle Lokalisation in Epithelien, Nerven und Gefäßen zu beobachten war. Die Re-Expression von Slit2 in Slit2-defizienten Zelllinien führte zu einer Hemmung der gerichteten Migration und Invasion. Der Robo1-Rezeptor knockdown hingegen stimulierte die Motilität von Tumorzellen mit endogener Slit2 Expression. Slit2-konditioniertes Medium aus Tumorzellen hemmte die Lamellipodienbildung und die Migration von Endothelzellen. In orthotopen humanen Xenograft-Modellen und einem murinen, syngenen Tumormodell reduzierte die Re-Expression von Slit2 in PDAC Zellen Tumorwachstum, Invasion, Metastasierung und Angiogenese. Zudem verminderte die Induktion von Slit2 in PDAC Zellen deren gerichtete Migration entlang aussprießender Neuriten in einem ex vivo Model. Die vorliegenden Daten weisen Slit2 die Funktion eines Tumorsuppressors im duktalen Pankreaskarzinom zu. Ein Verlust der Slit2-Robo Aktivität könnte somit Metastasierung und neuronale Invasion fördern und einen aggressiveren Phänotyp begünstigen.Early dissemination of pancreatic ductal adenocarcinoma (PDAC) via vascular routes and neural invasion limits curative therapy, suggesting a central role for the interaction of tumor cells with blood vessels and nerves in the tumor stroma. Slit2 and its Robo receptors constitute a system of guidance cues that function in axon guidance, angiogenesis and epithelial morphogenesis, respectively. Here, we studied the expression of Slit2 in PDAC and its function for tumor growth and dissemination. Slit2 mRNA expression was reduced in specimens of human PDAC as compared to non-transformed pancreas and low Slit2 mRNA expression correlated with a higher incidence and a higher extent of lymphatic metastasis. In contrast, the Slit2 receptors Robo1 and Robo4 were uniformly present in clinical samples of PDAC and healthy pancreas and displayed differential localization on epithelial tumor cells, nerves and tumor vasculature. Stable or inducible re-expression of Slit2 in Slit2-deficient PDAC cell lines inhibited directed migration and invasion. Conversely, Robo1-knockdown stimulated the motility of PDAC cells with endogenous Slit2 expression. Tumor cell derived Slit2, furthermore, suppressed lamellipodia formation and migration of primary endothelial cells. In vivo studies in orthotopic human xenograft and mouse syngeneic pancreatic cancer models revealed that re-expression of Slit2 in PDAC cells inhibited tumor growth, invasion, metastasis and angiogenesis. In addition, induction of Slit2 in PDAC cells impaired the unidirectional migration along outgrowing neurites in ex vivo co-cultures of tumor cells and dorsal root ganglia. These data provide evidence for a functional role of Slit2 as a tumor suppressor in human PDAC. A loss of Slit2-Robo activity as observed in human PDAC samples, might consequently promote metastasis and neural invasion and favors a more aggressive phenotype.
43
Azevedo-Pouly, Ana Clara P. "Biological functions of microRNA-216 and microRNA-217 during the development of pancreatic cancer." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374244806.
44
Schmahl, Michelle Jordan. "Metabolic Profiling of Urine, Fecal, and Serum Samples and Pancreatic Tumors and Evaluation of HMGA1 Expression Levels in Pancreatic Intraepithelial Neoplasia Cells in the Ptf1a-Cre; LSL-KrasG12D Transgenic Mouse Model of Pancreatic Cancer." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1523977530802748.
45
Rajurkar, Mihir S. "GLI-IKBKE Requirement In KRAS-Induced Pancreatic Tumorigenesis: A Dissertation." eScholarship@UMMS, 2014. https://escholarship.umassmed.edu/gsbs_diss/753.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC), one of the most aggressive human malignancies, is thought to be initiated by KRAS activation. Here, we find that transcriptional activation mediated by the GLI family of transcription factors, although dispensable for pancreatic development, is required for KRAS induced pancreatic transformation. Inhibition of GLI using a dominant-negative repressor (Gli3T) inhibits formation of precursor Pancreatic Intraepithelial Neoplasia (PanIN) lesions in mice, and significantly extends survival in a mouse model of PDAC. Further, ectopic activation of the GLI1/2 transcription factors in mouse pancreas accelerates KRAS driven tumor formation and reduces survival, underscoring the importance of GLI transcription factors in pancreatic tumorigenesis. Interestingly, we find that although canonical GLI activity is regulated by the Hedgehog ligands, in the context of PDAC, GLI transcription factors initiate a unique ligand-independent transcriptional program downstream of KRAS, that involves regulation of the RAS, PI3K/AKT, and NF-кB pathways.
We identify I-kappa-B kinase epsilon (IKBKE) as a PDAC specific target of GLI, that can also regulate GLI transcriptional activity via positive feedback mechanism involving regulation of GLI subcellular localization. Using human PDAC cells, and an in vivo model of pancreatic neoplasia, we establish IKBKE as a novel regulator pf pancreatic tumorigenesis that acts as an effector of KRAS/GLI, and mediates pancreatic transformation. We show that genetic knockout of Ikbke leads to a dramatic inhibition of initiation and progression of pancreatic intraepithelial viii neoplasia (PanIN) lesions in mice carrying pancreas specific activation of oncogenic Kras. Furthermore, we find that although IKBKE is a known NF-кB activator, it only modestly regulates NF-кB activity in PDAC. Instead, we find that IKBKE strongly promotes AKT phosphorylation in PDAC in vitro and in vivo, and that IKBKE mediates reactivation of AKT post-inhibition of mTOR. We also show that while mTOR inhibition alone does not significantly affect pancreatic tumorigenesis, combined inhibition of IKBKE and mTOR has a synergistic effect leading to significant decrease tumorigenicity of PDAC cells.
Together, our findings identify GLI/IKBKE signaling as an important oncogenic effector pathway of KRAS in PDAC that regulates tumorigenicity, cell proliferation, and apoptosis via regulation of AKT and NF-кB signaling. We provide proof of concept for therapeutic targeting of GLI/IKBKE in PDAC, and support the evaluation of IKBKE as a therapeutic target in treatment of pancreatic cancer, and IKBKE inhibition as a strategy to improve efficacy of mTOR inhibitors in the clinic.
46
Rajurkar, Mihir S. "GLI-IKBKE Requirement In KRAS-Induced Pancreatic Tumorigenesis: A Dissertation." eScholarship@UMMS, 2011. http://escholarship.umassmed.edu/gsbs_diss/753.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC), one of the most aggressive human malignancies, is thought to be initiated by KRAS activation. Here, we find that transcriptional activation mediated by the GLI family of transcription factors, although dispensable for pancreatic development, is required for KRAS induced pancreatic transformation. Inhibition of GLI using a dominant-negative repressor (Gli3T) inhibits formation of precursor Pancreatic Intraepithelial Neoplasia (PanIN) lesions in mice, and significantly extends survival in a mouse model of PDAC. Further, ectopic activation of the GLI1/2 transcription factors in mouse pancreas accelerates KRAS driven tumor formation and reduces survival, underscoring the importance of GLI transcription factors in pancreatic tumorigenesis. Interestingly, we find that although canonical GLI activity is regulated by the Hedgehog ligands, in the context of PDAC, GLI transcription factors initiate a unique ligand-independent transcriptional program downstream of KRAS, that involves regulation of the RAS, PI3K/AKT, and NF-кB pathways.
We identify I-kappa-B kinase epsilon (IKBKE) as a PDAC specific target of GLI, that can also regulate GLI transcriptional activity via positive feedback mechanism involving regulation of GLI subcellular localization. Using human PDAC cells, and an in vivo model of pancreatic neoplasia, we establish IKBKE as a novel regulator pf pancreatic tumorigenesis that acts as an effector of KRAS/GLI, and mediates pancreatic transformation. We show that genetic knockout of Ikbke leads to a dramatic inhibition of initiation and progression of pancreatic intraepithelial viii neoplasia (PanIN) lesions in mice carrying pancreas specific activation of oncogenic Kras. Furthermore, we find that although IKBKE is a known NF-кB activator, it only modestly regulates NF-кB activity in PDAC. Instead, we find that IKBKE strongly promotes AKT phosphorylation in PDAC in vitro and in vivo, and that IKBKE mediates reactivation of AKT post-inhibition of mTOR. We also show that while mTOR inhibition alone does not significantly affect pancreatic tumorigenesis, combined inhibition of IKBKE and mTOR has a synergistic effect leading to significant decrease tumorigenicity of PDAC cells.
Together, our findings identify GLI/IKBKE signaling as an important oncogenic effector pathway of KRAS in PDAC that regulates tumorigenicity, cell proliferation, and apoptosis via regulation of AKT and NF-кB signaling. We provide proof of concept for therapeutic targeting of GLI/IKBKE in PDAC, and support the evaluation of IKBKE as a therapeutic target in treatment of pancreatic cancer, and IKBKE inhibition as a strategy to improve efficacy of mTOR inhibitors in the clinic.
47
Quattrochi, Brian J. "Subtle Controllers: MicroRNAs Drive Pancreatic Tumorigenesis and Progression: A Dissertation." eScholarship@UMMS, 2015. https://escholarship.umassmed.edu/gsbs_diss/776.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies in the United States, with an average five-year survival rate of just 6.7%. One unifying aspect of PDAC is mutational activation of the KRAS oncogene, which occurs in over 90% of PDAC. Therefore, inhibiting KRAS function is likely an effective therapeutic strategy for this disease, and current research in our lab and others is focused on identifying downstream effectors of KRAS signaling that may be therapeutic targets. miRNAs are powerful regulators of gene expression that can behave as oncogenes or tumor suppressors. Dysregulation of miRNA expression is commonly observed in human tumors, including PDAC. The mir-17~92 cluster of miRNAs is an established oncogene in a variety of tumor contexts, and members of the mir-17~92 cluster are upregulated in PDAC, but their role has not been explored in vivo. This dissertation encompasses two studies exploring the role of miRNAs in pancreatic tumorigenesis. In Chapter II, I demonstrate that deletion of the mir-17~92 cluster impairs PDAC precursor lesion formation and maintenance, and correlates with reduced ERK signaling in these lesions. mir-17~92 deficient tumors and cell lines are also less invasive, which I attribute to the loss of the miR-19 family of miRNAs. In Chapter III, I find that Dicer heterozygosity inhibits PDAC metastasis, and that this phenotype is attributable to an increased sensitivity to anoikis. Ongoing experiments will determine whether shifts in particular miRNA signatures between cell lines can be attributed to this phenotype. Together these findings illustrate the importance of miRNA biogenesis, and the mir-17~92 cluster in particular, in supporting PDAC development and progression.
48
Quattrochi, Brian J. "Subtle Controllers: MicroRNAs Drive Pancreatic Tumorigenesis and Progression: A Dissertation." eScholarship@UMMS, 2004. http://escholarship.umassmed.edu/gsbs_diss/776.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies in the United States, with an average five-year survival rate of just 6.7%. One unifying aspect of PDAC is mutational activation of the KRAS oncogene, which occurs in over 90% of PDAC. Therefore, inhibiting KRAS function is likely an effective therapeutic strategy for this disease, and current research in our lab and others is focused on identifying downstream effectors of KRAS signaling that may be therapeutic targets. miRNAs are powerful regulators of gene expression that can behave as oncogenes or tumor suppressors. Dysregulation of miRNA expression is commonly observed in human tumors, including PDAC. The mir-17~92 cluster of miRNAs is an established oncogene in a variety of tumor contexts, and members of the mir-17~92 cluster are upregulated in PDAC, but their role has not been explored in vivo. This dissertation encompasses two studies exploring the role of miRNAs in pancreatic tumorigenesis. In Chapter II, I demonstrate that deletion of the mir-17~92 cluster impairs PDAC precursor lesion formation and maintenance, and correlates with reduced ERK signaling in these lesions. mir-17~92 deficient tumors and cell lines are also less invasive, which I attribute to the loss of the miR-19 family of miRNAs. In Chapter III, I find that Dicer heterozygosity inhibits PDAC metastasis, and that this phenotype is attributable to an increased sensitivity to anoikis. Ongoing experiments will determine whether shifts in particular miRNA signatures between cell lines can be attributed to this phenotype. Together these findings illustrate the importance of miRNA biogenesis, and the mir-17~92 cluster in particular, in supporting PDAC development and progression.
49
Vinaixa, Forner Judit 1991. "Role of Galectin-1 in pancreatic cancer stroma, a small but mischievous protein with a novel nuclear function." Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/666580.
Abstract:
Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive tumors; mostly due to its lack of symptoms, resulting in late diagnosis, and also due to the presence of an aggressive tumor microenvironment. Importantly, Galectin-1 (Gal-1) exerts a crucial role in modulating tumor-stroma crosstalk in this disease. In particular, our group has demonstrated that Gal-1 promotes tumor proliferation, metastasis, angiogenesis and immune evasion in PDA.
This protein is mainly produced by PDA stellate cells (PSC), however the intrinsic role of this protein in PSC biology is poorly understood. In the present study, we determine the impact of Gal-1 in HPSC proliferation, migration, invasion, activation and extracellular matrix organization. Using high throughput analysis (microarrays) we have defined the molecular mechanisms underlying Gal-1 functions in HPSC. Finally, considering that Gal-1 is highly expressed in HPSC nuclei, we elucidate the involvement of nuclear Gal-1 in the regulation of gene expression in these cells.El càncer de pàncrees representa un dels tumors més agressius, principalment, per la falta de símptomes, la tardana diagnosi i la presència d’un microambient tumoral agressiu. Galectina-1 (Gal-1) exerceix un paper fonamental modulant la interacció tumor-estroma. Concretament, el nostre grup ha demostrat que Gal-1 promou la proliferació tumoral, la metàstasi, l’angiogènesi i l’evasió de l’efecte del sistema immune. Aquesta proteïna es produïda principalment per les cèl·lules estelades del càncer de pàncrees (PSC), tot i així, la seua funció biològica en aquestes cèl·lules continua sent desconeguda. En aquest estudi, hem determinat la importància de Gal-1 en proliferació, migració, invasió, activació i en l’organització de la matriu extracel·lular. Mitjançant anàlisis genètics, hem definit els mecanismes moleculars a través dels quals Gal-1 exerceix les seues funcions. Finalment, considerant que Gal-1 es troba altament expressada en el nucli de les PSC, hem determinat la contribució de Gal-1 nuclear al control de l’expressió gènica.
50
Driscoll, David R. "The Impact of mTORC2 Signaling on the Initiation and Progression of KRAS-Driven Pancreatic Neoplasias: A Dissertation." eScholarship@UMMS, 2016. https://escholarship.umassmed.edu/gsbs_diss/821.
Abstract:
Pancreatic ductal adenocarcinoma (PDAC), the most common form of pancreatic cancer, develops through progression of premalignant pancreatic intraepithelial neoplasias (PanINs). In mouse-models, KRAS-activation in acinar cells induced an acinar-to-ductal metaplasia (ADM), and mutation of the Kras oncogene is believed to initiate PanIN formation. ADM is also promoted by pancreatic injury, which cooperates with activated KRAS to stimulate PanIN and PDAC formation from metaplastic ducts.
Our lab, and others, have shown that the downstream PI3K/AKT pathway is important for KRAS-mediated proliferation and survival in vitro and in vivo. Prior studies have demonstrated that full activation of AKT requires both PDK1- mediated phosphorylation of AKTT308 and mTOR complex 2 (mTORC2)-mediated phosphorylation of AKTS473. Given the importance of the PI3K/AKT signaling axis, I hypothesized that mTORC2 is required for KRAS-driven pancreatic tumorigenesis and investigated this relationship in mice by combining pancreasspecific expression of an activated KRASG12D molecule with deletion of the essential mTORC2 subunit RICTOR.
In the context of activated KRAS, Rictor-null pancreata developed fewer PanIN lesions; these lesions lacked mTORC2 signaling and their proliferation and progression were impaired. Higher levels of nuclear cyclin dependent kinase inhibitors (CDKIs) were maintained in Rictor-null lesions, and nuclear BMI1, a known regulator of the CDKI Cdkn2a, inversely correlated with their expression.Rictor was not required for KRAS-driven ADM following acute pancreatitis, however the inverse correlation between CDKIs and BMI1 was maintained in this system. Treatment of PDX-Cre;KRASG12D/+;Trp53R172H/+ mice with an mTORC1/2 inhibitor delayed tumor formation, and prolonged the survival of mice with late stage PDAC. Knockdown of Rictor in established PDAC cell lines impaired proliferation and anchorage independent growth supporting a role for mTORC2 in fully transformed cells.
These data suggest that mTORC2 cooperates with activated KRAS in the initiation and progression of PanIN lesions and is required for the transformation and maintenance of PDAC. My work illustrates phenotypic differences between pancreatic loss of Rictor and PDK1 in the context of KRAS, broadens our understanding of this signaling node and suggests that mTORC2 may potentially be a viable target for PDAC therapies.