Targeted Therapies for Pancreatic Cancer: Overview of Current Treatments and New Opportunities for Personalized Oncology.

Cytotoxic chemotherapy remains the only treatment option for most pancreatic ductal adenocarcinoma patients. Currently, the median overall survival of patients with advanced disease rarely exceeds 1 year. The complex network of pancreatic cancer composed of immune cells, endothelial cells, and cancer-associated fibroblasts confers intratumoral and intertumoral heterogeneity with distinct proliferative and metastatic propensity. This heterogeneity can explain why tumors do not behave uniformly and are able to escape therapy. The advance in technology of whole-genome sequencing has now provided the possibility of identifying every somatic mutation, copy-number change, and structural variant in a given cancer, giving rise to personalized targeted therapies. In this review, we provide an overview of the current and emerging treatment strategies in pancreatic cancer. By highlighting new paradigms in pancreatic ductal adenocarcinoma treatment, we hope to stimulate new thoughts for clinical trials aimed at improving patient outcomes

Editorial: Oncogenic RAS-Dependent Reprogramming of Cellular Plasticity.

No abstract availlable

Translation-Dependent Mechanisms Lead to PML Upregulation and Mediate Oncogenic K-RAS-Induced Cellular Senescence

Expression of oncogenic K-RAS in primary cells elicits oncogene-induced cellular senescence (OIS), a form of growth arrest that potently opposes tumourigenesis. This effect has been largely attributed to transcriptional mechanisms that depend on the p53 tumour suppressor protein. The PML tumour suppressor was initially identified as a component of the $PML-RAR\alpha$ oncoprotein of acute promyelocytic leukaemia (APL). PML, a critical OIS mediator, is upregulated by oncogenic K-RAS in vivo and in vitro. We demonstrate here that oncogenic K-RAS induces PML protein upregulation by activating the RAS/MEK1/mTOR/eIF4E pathway even in the absence of p53. Under these circumstances, PML mRNA is selectively associated to polysomes. Importantly, we find that the PML 5′ untranslated mRNA region plays a key role in mediating PML protein upregulation and that its presence is essential for an efficient OIS response. These findings demonstrate that upregulation of PML translation plays a central role in oncogenic K-RAS-induced OIS. Thus, selective translation initiation plays a critical role in tumour suppression with important therapeutic implications for the treatment of solid tumours and APL

An optimized protocol for the generation and monitoring of conditional orthotopic lung cancer in the KP mouse model using an adeno-associated virus vector compatible with biosafety level 1.

BACKGROUND The inducible Kras/p53 lung adenocarcinoma mouse model, which faithfully recapitulates human disease, is routinely initiated by the intratracheal instillation of a virus-based Cre recombinase delivery system. Handling virus-based delivery systems requires elevated biosafety levels, e.g., biosafety level 2 (BSL-2). However, in experimental animal research facilities, following exposure to viral vectors in a BSL-2 environment, rodents may not be reclassified to BSL-1 according to standard practice, preventing access to small animal micro-computed tomography (micro-CT) scanners that are typically housed in general access areas such as BSL-1 rooms. Therefore, our goal was to adapt the protocol so that the Cre-induced KP mouse model could be handled under BSL-1 conditions during the entire procedure. RESULTS The Kras-Lox-STOP-Lox-G12D/p53 flox/flox (KP)-based lung adenocarcinoma mouse model was activated by intratracheal instillation of either an adenoviral-based or a gutless, adeno-associated viral-based Cre delivery system. Tumor growth was monitored over time by micro-CT. We have successfully substituted the virus-based Cre delivery system with a commercially available, gutless, adeno-associated, Cre-expressing vector that allows the KP mouse model to be handled and imaged in a BSL-1 facility. By optimizing the anesthesia protocol and switching to a microscope-guided vector instillation procedure, productivity was increased and procedure-related complications were significantly reduced. In addition, repeated micro-CT analysis of individual animals allowed us to monitor tumor growth longitudinally, dramatically reducing the number of animals required per experiment. Finally, we documented the evolution of tumor volume for different doses, which revealed that individual tumor nodules induced by low-titer AAV-Cre transductions can be monitored over time by micro-CT. CONCLUSION Modifications to the anesthesia and instillation protocols increased the productivity of the original KP protocol. In addition, the switch to a gutless, adeno-associated, Cre-expressing vector allowed longitudinal monitoring of tumor growth under BSL-1 conditions, significantly reducing the number of animals required for an experiment, in line with the 3R principles

Synergistic effects of FGFR1 and PLK1 inhibitors target a metabolic liability in KRAS-mutant cancer.

KRAS oncoprotein is commonly mutated in human cancer, but effective therapies specifically targeting KRAS-driven tumors remain elusive. Here, we show that combined treatment with fibroblast growth factor receptor 1 (FGFR1) and polo-like kinase 1 (PLK1) inhibitors evoke synergistic cytotoxicity in KRAS-mutant tumor models in vitro and in vivo. Pharmacological and genetic suppression of FGFR1 and PLK1 synergizes to enhance anti-proliferative effects and cell death in KRAS-mutant lung and pancreatic but not colon nor KRAS wild-type cancer cells. Mechanistically, co-targeting FGFR1 and PLK1 upregulates reactive oxygen species (ROS), leading to oxidative stress-activated c-Jun N-terminal kinase (JNK)/p38 pathway and E2F1-induced apoptosis. We further delineate that autophagy protects from PLK1/FGFR1 inhibitor cytotoxicity and that antagonizing the compensation mechanism by clinically approved chloroquine fully realizes the therapeutic potential of PLK1 and FGFR1 targeting therapy, producing potent and durable responses in KRAS-mutant patient-derived xenografts and a genetically engineered mouse model of Kras-induced lung adenocarcinoma. These results suggest a previously unappreciated role for FGFR1 and PLK1 in the surveillance of metabolic stress and demonstrate a synergistic drug combination for treating KRAS-mutant cancer

The SUMO E3-ligase PIAS1 Regulates the Tumor Suppressor PML and Its Oncogenic Counterpart PML-RARA

The ubiquitin-like SUMO proteins covalently modify protein substrates and regulate their functional properties. In a broad spectrum of cancers, the tumor suppressor PML undergoes ubiquitin-mediated degradation primed by CK2 phosphorylation. Here we report that the SUMO E3-ligase inhibitor PIAS1 regulates oncogenic signaling through its ability to sumoylate PML and the PML-RARA oncoprotein of acute promyelocytic leukemia (APL). PIAS1-mediated SUMOylation of PML promoted CK2 interaction and ubiquitin/proteasome-mediated degradation of PML, attenuating its tumor suppressor functions. In addition, PIAS1-mediated SUMOylation of PML-RARA was essential for induction of its degradation by arsenic trioxide, an effective APL treatment. Moreover, PIAS1 suppression abrogated the ability of arsenic trioxide to trigger apoptosis in APL cells. Lastly, PIAS1 was also essential for PML degradation in non-small cell lung cancer cells, and PML and PIAS1 were inversely correlated in NSCLC cell lines and primary specimens. Together, our findings reveal novel roles for PIAS1 and the SUMOylation machinery in regulating oncogenic networks and the response to leukemia therapy

p130Cas/Cyclooxygenase-2 axis in the control of mesenchymal plasticity of breast cancer cells

Introduction: Intrinsic plasticity of breast carcinoma cells allows them to undergo a transient and reversible conversion into mesenchymal cells to disseminate into distant organs, where they can re-differentiate to an epithelial-like status to form a cohesive secondary mass. The p130Cas scaffold protein is overexpressed in human ER+ and HER2+ breast cancer where it contributes to cancer progression, invasion and resistance to therapy. However, its role in regulating mesenchymal aggressive breast cancer cells remains to be determined. The aim of this study was to investigate the molecular and functional involvement of this adaptor protein in breast cancer cell plasticity. Methods: We used silencing strategies and rescue experiments to evaluate phenotypic and biochemical changes from mesenchymal to epithelial traits in breast tumor cell lines. In the mouse A17 cell model previously related to mesenchymal cancer stem cells and basal-like breast cancer, we biochemically dissected the signaling pathways involved and performed functional in vivo tumor growth ability assays. The significance of the signaling platform was assessed in a human setting through the use of specific inhibitors in aggressive MDA-MB-231 subpopulation LM2-4175 cells. To evaluate the clinical relevance of the results, we analyzed publicly available microarray data from the Netherlands Cancer Institute and from the Koo Foundation Sun Yat-Sen Cancer Center. Results: We show that p130Cas silencing induces loss of mesenchymal features, by downregulating Vimentin, Snail, Slug and Twist transcriptional factors, resulting in the acquirement of epithelial-like traits. Mechanistically, p130Cas controls Cyclooxygenase-2 transcriptional expression, which in turn contributes to p130Cas-dependent maintenance of mesenchymal phenotype. This cascade of events also compromises in vivo tumor growth through inhibition of cell signaling controlling cell cycle progression. c-Src and JNK kinases are sequential players in p130Cas/ Cyclooxygenase-2 axis and their pharmacological inhibition is sufficient to downregulate Cyclooxygenase-2 leading to an epithelial phenotype. Finally, in silico microarray data analysis indicates that p130Cas and Cyclooxygenase-2 concomitant overexpression predicts poor survival and high probability of breast tumor recurrence. Conclusions: Overall, these data identify a new p130Cas/Cyclooxygenase-2 axis as a crucial element in the control of breast tumor plasticity, opening new therapeutic strategies leading to inhibition of these pathways in aggressive breast carcinoma

Ανάπτυξη διεργασιών απομάκρυνσης του φαινολικού φορτίου αποβλήτων ελαιουργείου με βάση τους μύκητες λευκής σήψης

Κατά την επεξεργασία του ελαιοκάρπου στα ελαιουργεία, ειδικά αυτά των τριών φάσεων, παράγονται μεγάλες ποσότητες υγρών αποβλήτων, τα οποία διατίθενται σε εδαφικούς και υδάτινους αποδέκτες προκαλώντας σημαντικά περιβαλλοντικά προβλήματα. Τα απόβλητα αυτά είναι βεβαρημένα από πλευράς ρυπαντικού φορτίου και παρουσιάζουν φυτοτοξική δράση. Το φαινολικό τους φορτίο είναι η κύρια ρυπαντική παράμετρος, ενώ έχει διαπιστωθεί ότι προκαλεί τοξική δράση στα μεθανογόνα βακτήρια κατά την βιολογική διεργασία της αναερόβιας χώνευσης. Τα τελευταία χρόνια μεγάλο ενδιαφέρον παρουσιάζει η βιολογική μέθοδος επεξεργασίας των υγρών αποβλήτων ελαιουργείου με τη χρήση μυκήτων λευκής σήψης (Βασιδιομύκητες) με σκοπό την αποτοξικοποίησή τους. Αυτό επιτυγχάνεται μέσω του αποτελεσματικού μεταβολισμού πολυφαινολικών συστατικών. Στην παρούσα μεταπτυχιακή διατριβή γίνεται μια προσέγγιση του πρόβληματος επεξεργασίας και αποτοξικοποίησης του κατσίγαρου με τη χρήση πέντε στελεχών μυκήτων του γένους Pleurotus. Αυτό αποτελεί ένα μέρος ενός γενικότερου σχεδίου συνδυασμένης δράσης ενός συστήματος βιοεπεξεργασίας του αποβλήτου, όπου το πρώτο στάδιο θα περιλαμβάνει την αερόβια ζύμωση με μύκητες λευκής σήψης και το δεύτερο την αναερόβια επεξεργασία του κατσίγαρου που προηγουμένως έχει υποστεί επεξεργασία με τη χρήση μυκήτων. Μετά την επιλογή του αποδοτικότερου στελέχους (PO 22) και εφόσον έχει προηγηθεί ο χαρακτηρισμός του αποβλήτου, ακολουθεί η αριστοποίηση των συνθηκών λειτουργίας καινοτόμων βιοαντιδραστήρων, κατάλληλων για τη βέλτιστη ανάπτυξη του επιλεγμένου μικροοργανισμού σε αιωρούμενη ή σε ακινητοποιημένη μορφή. Ακολούθως γίνεται ένα πείραμα διαλείποντος έργου (πείραμα BMP) όπου ερευνάται εάν το απόβλητο που προηγουμένως έχει βιοεπεξεργαστεί με μύκητες λευκής σήψης και συγκεκριμένα στελέχη του γένους Pleurotus για την απομάκρυνση του φαινολικού φορτίου επιδεικνύει καλύτερη συμπεριφορά στην αναερόβια επεξεργασία εν συγκρίσει με το μη επεξεργασμένο απόβλητο.During olive processing, especially three phase processing, large volumes of wastewaters (olive mill wastewaters, OMW) are generated and usually discarded to soils and water receptors constituting a major environmental concern. The OMW have a high pollution concentration and they show toxic effect. Their phenolic concentration presents the main environmental concern, and it has been ascertained that it has a toxic effect on the methanogens during anaerobic digestion. Over the last years the biological method of treating olive mill wastewaters presents great interest and white rot fungi (Basidiomycetes) are used in order to detoxicate the wastewaters. This is achieved through the effective metabolism of polyphenolics. This work approaches the problem of treating and detoxicating OMW by using five strains of fungi of the Pleurotus species. This constitutes a part of a wider plan of a combined system involving the biotreatment of the waste, where the fist stage (pre-treatment) shall include the aerobic fermentation with the use of white rot fungi and the second stage shall involve the anaerobic treatment of the OMW which has previously undergone treatment with fungi. Once the OMW has been characterised the most efficient strain (PO 22) is chosen. Then the operation conditions of the innovative bioreactors which are suitable for optimum growth of micro organisms in a floating or immobilised form shall be optimised. Then a batch experiment (BMP experiment) shall be carried out to find out whether the waste which has been previously biotreated with strains of the Pleurotus species for the removal of phenolics exhibits a better anaerobic-ally treatment as opposed to the non treated waste

Lipid Metabolic Alterations in KRAS Mutant Tumors: Unmasking New Vulnerabilities for Cancer Therapy

KRAS is one of the most commonly mutated genes, an event that leads to development of highly aggressive and resistant to any type of available therapy tumors. Mutated KRAS drives a complex network of lipid metabolic rearrangements to support the adaptation of cancer cells to harsh environmental conditions and ensure their survival. Because there has been only a little success in the continuous efforts of effectively targeting KRAS-driven tumors, it is of outmost importance to delineate the exact mechanisms of how they get rewired, leading to this distinctive phenotype. Therefore, the aim of this review is to summarize the available data acquired over the last years with regard to the lipid metabolic regulation of KRAS-driven tumors and elucidate their specific characteristics in an attempt to unravel novel therapeutic targets

Targeting Long Chain Acyl-CoA Synthetases for Cancer Therapy.

The deregulation of cancer cell metabolic networks is now recognized as one of the hallmarks of cancer. Abnormal lipid synthesis and extracellular lipid uptake are advantageous modifications fueling the needs of uncontrolled cancer cell proliferation. Fatty acids are placed at the crossroads of anabolic and catabolic pathways, as they are implicated in the synthesis of phospholipids and triacylglycerols, or they can undergo β-oxidation. Key players to these decisions are the long-chain acyl-CoA synthetases, which are enzymes that catalyze the activation of long-chain fatty acids of 12-22 carbons. Importantly, the long-chain acyl-CoA synthetases are deregulated in many types of tumors, providing a rationale for anti-tumor therapeutic opportunities. The purpose of this review is to summarize the last up-to-date findings regarding their role in cancer, and to discuss the related emerging tumor targeting opportunities