Pancreatic cancer is one of the deadliest types of malignant diseases. Asymptomatic early tumour stages, tumour heterogeneity, cancer cell plasticity and unusually dense pancreatic stroma are responsible for the poor prognosis attributed to late diagnosis and therapy resistance. Therefore, targeting of a pivotal element common for any cell type within the tumour, e.g. mitochondria, may bring significant improvement. In this work, we demonstrate mitochondrial targeting of metformin, an anti-diabetic drug associated with reduced risk of developing pancreatic cancer, substantially increases accumulation of the compound in mitochondria. In consequence, we show that mitochondrially targeted metformin, MitoMet, eliminates pancreatic cancer cells in more than 1000-fold lower concentration than used for its parental compound. Following interaction with respiratory complex I (CI), MitoMet inhibits mitochondrial respiration, activates AMP-activated protein kinase pathway and causes depolarization of mitochondrial membrane potential in pancreatic cancer cells. Moreover, MitoMet induces cell cycle arrest and apoptosis, which is partially mediated via increased level of reactive oxygen species (ROS), and suppresses pancreatic tumour growth in vivo. Interestingly, SMAD4-deficient pancreatic cancer cells manifest...

Over 5000 flavonoids have been identified so far and many of these are known to have antineoplastic properties. The relationships between the targeting activities by these compounds on cancer cells and the specific features that determine their molecular structures are not completely elucidated. Here we report the differential cytotoxic effects of two unsubstituted ring B flavonoids that differ solely in the presence of a C2, C3 double bond in ring C, on human cancer cells of the lung (A549), pancreas (MIA PaCa-2, Panc28), colon (HCT 116, CaCo-2), Liver (HepG2), and breast (SKBr3). These compounds were extracted from Chromolaena leivensis (Hieron) a plant belonging to the genus Chromolaena reputed to have antitumor activities. 3, 5 dihydroxy-7-methoxyflavone induce apoptosis in cancer cells of the lung A549, pancreas MIA PaCa-2 and Panc28, and colon HCT116, but not on Caco-2; whereas 3,5 dihydroxy-7-methoxyflavanone display proliferative effects in A549, Panc 28, MIA PaCa, and HCT116 cells at low concentrations, and slight cytotoxicity only on CaCo-2, a cancer cell line with a higher differentiation status than other cells tested. At the concentrations studied (5-80µM) neither compound demonstrated activity against cancer cells of the liver (HepG2) or breast (SKBr3) as indicated by MTT cell viability assays. When used in combination with 3,5 dihydroxy-7-methoxyflavone in pancreatic cancer cells, the targeting preference of 3, 5 dihydroxy-7-methoxyflavanone is altered, and a significant increase in inhibition of cell viability is observed 48 hours after dosing. The presence or absence of the C2, C3 double bond in ring C, accounts for electrochemical and structural changes that dictate differential specificity towards cancer cells. 3,5 dihydroxy-7-methoxyflavone has a more planar structure, whereas the absence of the double bond in C2, C3 causes ring B to adopt a perpendicular orientation to the plane formed by rings A and C and the OH group at C3.

Pancreatic cancer (PC) remains a significant, unresolved issue because of its complex genetic blueprint and lack of reliable detection markers. The purpose of this study was to examine the possible correlation between tobacco use, gender, and age in the etiopathogenesis of PC and other cancer types with a shared-gene association (CTSG-A). The unified paradigm of cancer causation was used to understand the pathopoiesis mechanism of smoking and shared genes in PC. A cross-sectional study was performed using secondary data from the cancer survivorship module of the 2014 Behavioral Risk Factor Surveillance System survey. Results of ordinal logistic regression analyses indicated no correlation between smoking and prevalence of PC and CTSG-A, but gender and age were significant predictors. Gender has a statistically significant effect on the prediction of PC/ CTSG-A induction and promotion. Increased probability of developing the disease was found as the person reach the age between 62 and 69 years of age. Findings may enhance the understanding of environmental, genetic, and biodemographic interactions in disease evolution (induction, promotion, and expression periods). Findings may also be used to promote population health and improve health behaviors for individuals in vulnerable, high-risk groups.

<p>Oncogenic mutations in KRAS are present in approximately 95% of patients diagnosed with pancreatic ductal adenocarcinoma (<b>PDAC</b>) and are considered the initiating event during the development of pancreatic intraepithelial neoplasia (<b>PanIN</b>) precursor lesions. While it is well established that KRAS mutations can drive the initiation of pancreatic oncogenesis, the effects of oncogenic KRAS signaling on regulation of phosphatases during this process is not fully appreciated. Protein Phosphatase 2A (<b>PP2A</b>) has been implicated in suppressing KRAS-driven cellular transformation. However, low PP2A activity is observed in PDAC cells compared to non-transformed cells, suggesting that suppression of PP2A activity is an important step in the overall development of PDAC. In the current study, we demonstrate that KRASG12D induces the expression of both Cancerous Inhibitor of PP2A (<b>CIP2A</b>), an endogenous inhibitor of PP2A activity, and the PP2A target, c-MYC. Consistent with these findings, KRASG12D sequestered the specific PP2A subunit responsible for c-MYC degradation, B56a, away from the active PP2A holoenzyme in a CIP2A-dependent manner. During PDAC initiation <i>in vivo</i>, knockout of B56a promoted KRASG12D tumorigenesis by accelerating acinar-to-ductal metaplasia (<b>ADM</b>) and the formation of PanIN lesions. The process of ADM was attenuated <i>ex vivo</i> in response to pharmacological re-activation of PP2A utilizing direct small molecule activators of PP2A (<b>SMAP</b>s). Together, the results of this study suggest that suppression of PP2A-B56a through KRAS signaling can promote Myc-driven initiation of pancreatic tumorigenesis.</p>

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Pancreatic cancer is the seventh leading cause of cancer related mortalities worldwide and incidences are increasing. The prognosis remains poor as the 5-year survival rate is below 10%. This can be partly explained by the silent progression of disease as most patients present with advanced disease at time of diagnosis. In turn, surgical resection, the only potential curative measure, is not possible in nearly 80% of cases due to the occurrence of distant metastasis and/or infiltration of major vessels in close proximity to the pancreas. In patients with localized but advanced disease, resectability can be achieved in some cases by initiation of a neoCTx. However, as neoCTx is commonly conducted by administering multi-drug treatments, severe side effects occur frequently, which require an adaption of drug doses administered. In this study, we revealed the negative impact of these drug dose changes during neoCTx on the patients´ treatment outcome. R0 resections were significantly less frequently observed, and the N-status significantly impacted by the tumor regression grade, which in turn trended towards minor response in the cohort of patients that did not sustain full dose course prior surgery. In turn, treatment of LA PDAC could be improved by increasing the proportion of patients that undergo neoCTx without any changes of the treatment schedule. Patient-derived PDAC organoid could serve as an avatar of patients´ tumor disease on which optimal treatment protocols could be tested. In this study, a large living PDAC PDO biobank successfully has been established from surgical resection specimens as well as EUS guided FNA samples. Subsequently, a new protocol for molecular subtyping of PDAC on organoids was established by assessing the expression level of KRT81 and CFTR, as a replacement for HNF1a, using IF staining. Strikingly, we observed identical PDAC subtypes in PDOs and their respective tissue of origin in nearly all cases. This observation allowed the assumption that PDOs could indeed be used as patient-individual avatars to identify treatment sensitivities and resistances, as they share fundamental molecular properties with the tissue they have been initiated from. Extensive pharmacotyping was performed for many PDO lines by testing the response behavior to the multi-drug regimens FOLFIRINOX and Gem/Pac, as well as their respective single drug compounds. As a result, we observed diverse response patterns for each PDAC PDO line. A poor response to FOLFIRINOX did not necessarily imply a resistance to Gem/Pac. PDO pharmacotyping could guide treatment decision making in the foreseeable future. Moreover, when the non-efficient drug was removed, no changes of overall efficacy of treatment in PDOs was observed, implying that additional therapy improvements could be possible using this ex vivo model. This observation was true for both commonly used chemotherapy protocols, FOLFIRINOX and Gem/Pac and could result in less drug mediated side effects under (neo)adjuvant CTx without impacting treatment efficacy. Yet, the main goal of this study was to assess if PDAC PDOs can be used to predict the neoCTx outcome of PDAC patients. All methods required to address this issue in a prospective clinical trial have been established as a protocol for PDAC PDOs initiation from minimal starting material has been established and subsequently improved resulting in take rates of up to 80%. To support this study, we successfully secured patient enrollment from a second clinical center, which will increase the number of recruited patients in the future. Unfortunately, at the time of writing this thesis, patient numbers were not sufficient to answer the question of the predictive value of PDAC PDOs in regard to the current standard of care.

P8 est un gène lié au stress cellulaire qui a été identifié et caractérisé dans notre laboratoire. Il est surexprimé dans diverses pathologies, et plus particulièrement dans l'adénocarcinome pancréatique. Notre étude se focalise sur le rôle de p8 dans la progression tumorale et la formation des métastases du cancer du pancréas. Dans ce travail, nous avons démontré, dans un premier temps, que p8 régule la migration, l'adhésion et l'invasion cellulaire induites par diverses molécules dont le TGF-&#946;1, par le biais de la GTPase CDC42, dont il contrôle l'expression et l'activité. Nous avons prouvé aussi que la présence de p8 est nécessaire pour la mise en place d'une transition épithélio-mésenchymateuse, facilitant ainsi l'action pro-tumorale du TGF-&#946;1. Enfin, une analyse morphologique d'adénocarcinomes pancréatiques humains et murins nous a permis d'identifier la présence de cellules « cannibales », déficientes en p8, capables de phagocyter et ainsi limiter la prolifération d'autres cellules. Nous avons décortiqué ce mécanisme au niveau moléculaire. Son étude nous a permis de conclure, qu'en absence de p8, une nouvelle transition de type épithélio-phagocytaire est instaurée, ayant comme résultat un cannibalisme cellulaire, potentialisé notamment par le TGF-&#946;1, qui agirait dans ce cas comme un agent anti-tumoral. L'avancée de ces résultats donne place à des nouvelles perspectives vis-à-vis de l'importance de p8, d'abord d'un point de vue moléculaire sur les actions pro et anti-tumorales du TGF-&#946;1, ensuite en tant que potentielle cible thérapeutique dans le cancer du pancréas. / P8 is a gene related to cellular stress, identified and characterized in our laboratory, and overexpressed in several diseases, especially in pancreatic cancer (PDAC). Our study focuses on the role of p8 in tumor progression and metastasis formation in PDAC. In this work, we have demonstrated that firstly, p8 regulates pancreatic cancer cell migration, invasion and adhesion, induced by several molecules like TGF-&#946;1, through CDC42, a small GTPase, whose expression and activation is controlled by p8. We also established that p8 is necessary to set up epithelial-to-mesenchymal transition, promoting TGF-&#946;1 pro-tumoral effects. Finally, morphological analysis of human and murine pancreatic cancer, allowed us to identify “cannibal” cells, in which p8 expression was absent, able to phagocytose another cells and in this way limit its proliferation. We dissected the mechanism involved in this process at the molecular level. This study led us to conclude that when p8 is absent, a new epithelial-to-phagocytic transition takes place, resulting in cell cannibalism, maximized by TGF-&#946;1 action that will play an anti-tumoral role. These results underscore, on one hand, the crucial role of p8, at the molecular level, over the pro and anti-tumoral effects of TGF-&#946;1 and on the other hand its potential role in pancreatic cancer therapy.

La progression maligne de l’adénocarcinome canalaire pancréatique (ADKP) s'accompagne d'une profonde réaction desmoplasique, limitant la vascularisation de la tumeur et de fait privant les cellules tumorales en nutriments, forçant les cellules tumorales à adapter leur métabolisme. L’objectif de thèse était de définir les changements métaboliques relatifs à l’ADKP. Par une analyse transcriptomique des tumeurs pancréatiques développées de manière spontanée chez les souris, nous avons établi le profil métabolique des ADKPs lié aux acides aminés au cours de leur progression. Ainsi, nous avons montré que les voies métaboliques de la proline et des acides aminés à chaînes branchées, en particulier le catabolisme de la leucine, sont celles étant les plus dérégulées dans l’ADKP. Concernant le métabolisme de la proline, nous avons montré que les cellules tumorales privées en nutriments capturent et utilisent le collagène, produit par les fibroblastes du stroma tumoral grâce à la macropinocytose, de façon le dégrader en proline. Aussi, l’inhibition de la dégradation de la proline entraine une diminution de la prolifération tumorale in vitro et in vivo. Concernant la leucine, nous montrons que l’élément clé de ce métabolisme est un de ces produits de dégradation finaux à savoir le β-hydroxybutyrate (βOHB) dont la production repose sur une enzyme cruciale : HMGCL. Dans nos travaux, nous démontrons que la suppression d’HMGCL dans les cellules d’ADKP humains entrave leurs capacités oncogéniques et métastatiques in vitro et in vivo. De plus, nous montrons in vivo que le βOHB augmente la croissance tumorale ainsi que la formation de métastases. / The malignant progression of pancreatic ductal adenocarcinoma (PDAC) is accompanied by a profound desmoplasia, depriving tumor cells from oxygen and nutrients, which forces tumor cells to adapt their metabolism to proliferate. The thesis purpose is to define the metabolic changes related to ADKP. Using a transcriptomic analysis of PDAC from mice model, we established the PDAC metabolic profile. Focusing on amino acid metabolic pathways, we identified the metabolic pathways of proline and the branched-chain amino acid, especially the leucine catabolism, as the most deregulated in ADKP compared to the normal pancreas. We demonstrated that tumor cells take up collagen-derived fibroblasts, thanks macropinocytosis, when they are nutrient deprived. Once collagen is internalized, its subsequent digestion supplies TCA with proline. Also, inhibition of proline degradation leads to a decrease in tumor proliferation in vitro and in vivo. We have shown leucine catabolism is specific to tumor cells and the final degradation products: the β-hydroxybutyrate (βOHB) appears as a key element of this metabolism. To produce βOHB, tumor cells use HMGCL, a crucial enzyme involved in leucine degradation. In our work we demonstrated that HMGCL suppression in PDAC cells decreases their oncogenic and metastatic capacities in vitro and in vivo. In addition, we have demonstrated in vivo that βOHB increases tumor growth and metastasis formation. Thus, our works show 1/ the metabolic plasticity of cells, 2/the influence of microenvironment on tumor cell metabolism, 3/ the importance to study tumor metabolism for the finding of new therapeutic targets.

Jährlich erkranken in Deutschland über 11.000 Patienten an Pankreaskarzinomen. Für die ganz überwiegende Mehrzahl dieser Patienten ist die Diagnosestellung gleichbedeutend mit einem Todesurteil innerhalb von wenigen Wochen, hauptsächlich bedingt durch das meist fortgeschrittene Krankheitsstadium bei Diagnosestellung sowie die relative Therapieresistenz des Tumors. Die vorliegende Arbeit faßt wissenschaftliche Untersuchungen zusammen, die in den zurückliegenden vier Jahren in Berlin zu dieser Thematik durchgeführt wurden. Stadienadaptiert wurden Behandlungskonzepte und klinische Studien entwickelt und durchgeführt, die von der adjuvanten Chemotherapie über ein Radiochemo-therapiekonzept bei lokal fortgeschrittenen Stadien hin zur Entwicklung einer neuen Zytostatika-Kombinationstherapie für die Behandlung metastasierter Pankreastumoren im Rahmen einer multinationalen Phase III Studie geführt haben. Neben diesen Schemata konnte auch eine wirksame Zweitlinientherapie geprüft werden. An Tumormaterial konnte gezeigt werden, daß sich keine Her2/neu-Überexpressionen bei Pankreastumoren nachweisen lassen, die therapeutisch nutzbar wären. Bei ca. 80 % aller Pankreaskarzinome lassen sich Mutationen des K-ras-Onkogens nachweisen. In Kooperation mit einer anderen Arbeitsgruppe wurde ein Verfahren entwickelt, mit dem sich qualitativ und semiquantitiativ schnell und zuverlässig ras-Mutationen nachweisen lassen. Diese klinischen Studienergebnisse geben Grund zur Hoffnung, die Prognose von Patienten mit Pankreaskarzinomen in den nächsten Jahren durch die hier vorgestellten Konzepte zu verbessern. Fortschritte im Verständnis der molekularen Karzinogenese, in Diagnostik und Therapie lassen in naher Zukunft Ergebnisse erwarten, die zumindest denen bei anderen soliden Tumoren nahekommen. Daher ist der vereinzelt noch verbreitete therapeutische Nihilismus bei der Behandlung des Pankreaskarzinoms als nicht länger gerechtfertigt und akzeptabel anzusehen. / In Germany, more than 11,000 patients are diagnosed with pancreatic cancer each year. For the vast majority, this means a death verdict within a few weeks, primarily due to the advanced stage of the disease at diagnosis and the relative chemoresistance of the tumor. This thesis summarizes the scientific work regarding pancreatic cancer that has been done within the last four years. Several clinical treatment concepts and studies were developed and conducted that covered the different stages of the disease, including adjuvant therapy, radiochemotherapy for locally advanced disease and a multinational phase III study for the patients with metastatic disease. In addition, an effective second line regimen was developed. Using tumor material, we found no overexpression of Her2/neu which would have been a therapeutically usable target. Mutations of the K-ras oncogene can be found in approximately 80% of patients with pancreas carcinoma. A method for a rapid and reliable qualitative and semiquantitative determination detection of ras mutations was developed in cooperation with another research group. The clinical results give rise to the hope that the prognosis of patients with pancreatic carcinoma can be improved during the next years using the concepts outlined above. Recent improvements in our understanding of the molecular carcinognesis together with advances in diagnostics and therapy give rise to the expectation that clinical results will be achievable that will be at least as good as those for other solid tumors. Therefore, nihilism regarding the treatment of pancreatic cancer that still can be found is no longer justifiable or acceptable.