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International audience; The recycling activity of cytidine deaminase (CDA) within the pyrimidine salvage pathway is essential to DNA and RNA synthesis. As such, CDA deficiency can lead to replicative stress, notably in Bloom syndrome. Alternatively, CDA also can deaminate cytidine and deoxycytidine analog-based therapies, such as gemcitabine. Thus, CDA overexpression is often associated with lower systemic, chemotherapy-related, adverse effects but also with resistance to treatment. Considering the increasing interest of CDA in cancer chemoresistance, the aims of this review are to describe CDA structure, regulation of expression, and activity, and to report the therapeutic strategies based on CDA expression that recently emerged for tumor treatment.

MicroRNAs from the miR-200 family are commonly associated with the inhibition of the metastatic potential of cancer cells, following inhibition of ZEB transcription factors expression and epithelial-to-mesenchymal transition. However, previous studies performed in pancreatic adenocarcinoma revealed a more complex picture challenging this canonical model. To gain better insights into the role of miR-200 family members in this disease, we analyzed the expression of miR-200a, miR-200b, miR-200c, miR-141, miR-429, and miR-205, and ZEB1, ZEB2, and CDH1 in pancreatic tumors and matching normal adjacent parenchyma and patient-derived xenografts. We found that miR-200a, miR-429, and miR-205 are frequently overexpressed in pancreatic tumors, whereas CDH1 is downregulated, and ZEB1 and ZEB2 levels remain unchanged. Furthermore, we measured a positive correlation between miR-200 family members and CDH1 expression, and a negative correlation between ZEB1 and miR-200c, miR-141, and miR-205 expression, respectively. Interestingly, we identified significant changes in expression of epithelial-to-mesenchymal transition regulators and miR-200 members in patient-derived xenografts. Lastly, functional studies revealed that miR-141 and miR-429 inhibit the tumorigenic potential of pancreatic cancer cells. Taken together, this comprehensive analysis strongly suggests that miRNAs from the miR-200 family, and in particular miR-429, may act as a tumor suppressor gene in pancreatic cancer. Keywords: pancreatic cancer, patient-derived xenograft, miR-200 family, miR-429

International audience

Pancreatic ductal adenocarcinoma (PDAC) is a paradigmatic model of micrometastatic disease, characterized by both relapse of surgery and failure of long-term disease control with chemotherapies in resected, locally advanced unresectable and metastatic patients. Molecular characterization of large cohorts of PDAC patients failed to identify actionable pathways associated with mutations except for oncogenic Kras, found in more than 80% of all patients. Class I PI3K being a key regulator of both cell survival and cell migration, we questioned if nonmutated PI3K activity downstream oncogenic Kras is a clinically relevant target for this pathology. To achieve this goal, we devised a novel preclinical protocol in a genetically engineered mouse model (GEMM) including a noninvasive monitoring using circulating cell-free DNA (cfDNA) level as a novel biomarker of micrometastatic disease. We previously showed that, downstream Kras, nonmutant ubiquitous PI3Kalpha is crucial for PDAC development. Among all the mRNA expression-based hallmarks of biologic pathways, we now show that PI3K/Akt/mTOR hallmark is significantly increased in PDAC patients with advanced metastatic disease. High scoring of PI3Kalpha activation, based on expression levels of PI3Kalpha-regulated curated genes, is correlated to a poor prognosis, and is found in metastatic PDAC cell lines and in patient-derived ex vivo cultures of locally invasive PDAC cancer cells. When testing global or isoform-selective inhibitors in GEMM and human cell lines, we show that biologically efficient PI3K inhibitors annihilate PI3Kalpha strongly, but not necessarily specifically, among the four class I PI3K isoforms, resulting in Akt2 inactivation. Similar results are obtained with siRNA and in PIK3CA oncogenic cell lines. PI3Kalpha controls pancreatic tumor cell line motility and migration. In a GEMM model of PDAC, mice with high level of cfDNA present a shorter survival and develop a metastatic disease. Genetic or pharmacologic inhibition of PI3Kalpha in these mice decreases tumor volume, metastasis, ascitic fluid development, cfDNA quantity and M2 macrophage infiltration. Here, we used GEMMs to define a cfDNA-positive aggressive subtype of PDAC and identify a pharmacologically actionable prometastatic feature driven by PI3Kalpha. We propose PI3K as a therapeutic strategy to suppress PDAC progression and metastasis by scavenging peritumoral CD206-positive macrophages. Our data demonstrate that PI3K agents could be efficient on micrometastatic disease (measured by cfDNA), resulting in delay on macrometastatic dissemination. This abstract is also being presented as Poster B04. Citation Format: Benoit Thibault, Fernanda Ramos-Delgado, Elvire Pons-Tostivint, Nicole Therville, Gabriella Reyes-Castellanos, Marie Tosolini, Jean-Pierre Delord, Dieter Saur, Alice Carrier, Pierre Cordelier, Céline Basset, Julie Guillermet-Guibert. Pancreatic ductal adenocarcinoma requires PI3Kalpha activity to accelerate circulating DNA-positive metastatic disease [abstract]. In: Proceedings of the AACR Special Conference on Targeting PI3K/mTOR Signaling; 2018 Nov 30-Dec 8; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(10_Suppl):Abstract nr PR07.

Pancreatic ductal adenocarcinoma (PDAC) offers an optimal model for discovering >druggable> molecular pathways that participate in inflammation-associated cancer development. Chronic pancreatitis, a common prolonged inflammatory disease, behaves as a well-known premalignant condition that contributes to PDAC development. Although the mechanisms underlying the pancreatitis-to-cancer transition remain to be fully elucidated, emerging evidence supports the hypothesis that the actions of proinflammatory mediators on cells harboring Kras mutations promote neoplastic transformation. Recent elegant studies demonstrated that the IL17 pathway mediates this phenomenon and can be targeted with antibodies, but the downstream mechanisms by which IL17 functions during this transition are currently unclear. In this study, we demonstrate that IL17 induces the expression of REG3β, a wellknown mediator of pancreatitis, during acinar-to-ductal metaplasia and in early pancreatic intraepithelial neoplasia (PanIN) lesions. Furthermore, we found that REG3β promotes cell growth and decreases sensitivity to cell death through activation of the gp130-JAK2-STAT3-dependent pathway. Genetic inactivation of REG3β in the context of oncogenic Kras-driven PDAC resulted in reduced PanIN formation, an effect that could be rescued by administration of exogenous REG3β. Taken together, our findings provide mechanistic insight into the pathways underlying inflammation-associated pancreatic cancer, revealing a dual and contextual pathophysiologic role for REG3β during pancreatitis and PDAC initiation., This work was supported by La Ligue Contre le Cancer, INCa, Canceropole PACA, DGOS (labellisation SIRIC), and INSERM to J.L. Iovanna; NIH grants DK52913, the Mayo Clinic Center for Cell Signaling in Gastroenterology (P30DK084567), and the Mayo Foundation to R. Urrutia; by Fraternal Order of Eagles Cancer Award to G. Lomberk; and the FIS grant from Instituto de Salud Carlos III (PI13/01224) to E. Folch-Puy

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with a mortality that is almost identical to incidence. Because early detected PDAC is potentially curable, blood-based biomarkers that could detect currently developing neoplasia would improve patient survival and management. PDAC develops from pancreatic intraepithelial neoplasia (PanIN) lesions, graded from low grade (PanIN1) to high grade (PanIN3). We made the hypothesis that specific proteomic signatures from each precancerous stage exist and are detectable in plasma. Methods: We explored the peptide profiles of microdissected PanIN cells and of plasma samples corresponding to the different PanIN grade from genetically engineered mouse models of PDAC using capillary electrophoresis coupled to mass spectrometry (CE-MS) and Chip-MS/MS. Results: We successfully characterised differential peptides profiles from PanIN microdissected cells. We found that plasma from tumor-bearing mice and age-matched controls exhibit discriminative peptide signatures. We also determined plasma peptide signatures corresponding to low- and high-grade precancerous step present in the mice pancreas using the two mass spectrometry technologies. Importantly, we identified biomarkers specific of PanIN3. Conclusions: We demonstrate that benign and advanced PanIN lesions display distinct plasma peptide patterns. This strongly supports the perspectives of developing a non-invasive screening test for prediction and early detection of PDAC.

The understanding of the biology of pancreatic carcinoma has greatly benefited from studies of genetic/epigenetic alterations and molecular expression in experimental models as well as precancerous and cancerous tissues by mean of molecular amplification and large-scale transcriptoma analysis. P16, TP53, DPC4/Smad4 tumor suppressor pathways are genetically inactivated in the majority of pancreatic carcinomas, whereas oncogenic k-ras is activated. The activating point mutation of the KRAS oncogene on codon 12 is the major event and occurs early in pancreatic carcinogenesis. At a late stage of tumor development, an increase of telomerase activity, an over expression of growth factors and/or their receptors (EGF, Nerve Growth Factor, gastrin), of pro-angiogenic factors (VEGF, FGF, PDGF), of invasiveness factors (metalloproteinases, tissue plasminogen activators) occurs. The microenvironment plays also a key role in the invasive and metastatic process of pancreatic carcinoma with a strong relationship between cancerous cells and pancreatic stellate cells as well as extracellular matrix. This microenvironment strongly participates to the tumor fibrosis, hypoxia and hypovascularization inducing an inaccessibility of drugs. Nowadays, the targeting of microenvironment takes a special place in the new therapeutic strategies of pancreatic cancer in combination with chemotherapy.

This phase 1 trial was aimed to determine the safety, pharmacokinetics, and preliminary clinical activity of CYL-02, a nonviral gene therapy product that sensitizes pancreatic cancer cells to chemotherapy. CYL-02 was administrated using endoscopic ultrasound in 22 patients with pancreatic cancer that concomitantly received chemotherapy (gemcitabine). The maximum-tolerated dose (MTD) exceeded the maximal feasible dose of CYL-02 and was not identified. Treatment-related toxicities were mild, without serious adverse events. Pharmacokinetic analysis revealed a dose-dependent increase in CYL-02 DNA exposure in blood and tumors, while therapeutic RNAs were detected in tumors. No objective response was observed, but nine patients showed stable disease up to 6 months following treatment and two of these patients experienced long-term survival. Panels of plasmatic microRNAs and proteins were identified as predictive of gene therapy efficacy. We demonstrate that CYL-02 nonviral gene therapy has a favorable safety profile and is well tolerated in patients. We characterize CYL-02 biodistribution and demonstrate therapeutic gene expression in tumors. Treated patients experienced stability of disease and predictive biomarkers of response to treatment were identified. These promising results warrant further evaluation in phase 2 clinical trial.

A recent death projection has placed pancreatic ductal adenocarcinoma as the second cause of death by cancer in 2030. The prognosis for pancreatic cancer is very poor and there is a great need for new treatments that can change this poor outcome. Developments of therapeutic innovations in combination with conventional chemotherapy are needed urgently. Among innovative treatments the gene therapy offers a promising avenue. The present review gives an overview of the general strategy of gene therapy as well as the limitations and stakes of the different experimental in vivo models, expression vectors (synthetic and viral), molecular tools (interference RNA, genome editing) and therapeutic genes (tumor suppressor genes, antiangiogenic and pro-apoptotic genes, suicide genes). The latest developments in pancreatic carcinoma gene therapy are described including gene-based tumor cell sensitization to chemotherapy, vaccination and adoptive immunotherapy (chimeric antigen receptor T-cells strategy). Nowadays, there is a specific development of oncolytic virus therapies including oncolytic adenoviruses, herpes virus, parvovirus or reovirus. A summary of all published and on-going phase-1 trials is given. Most of them associate gene therapy and chemotherapy or radiochemotherapy. The first results are encouraging for most of the trials but remain to be confirmed in phase 2 trials.

Pancreas transcription factor 1a (PTF1a) plays a crucial role in the early development of the pancreas and in the maintenance of the acinar cell phenotype. Several transcriptional mechanisms regulating expression of PTF1a have been identified. However, regulation of PTF1a protein stability and degradation is still unexplored. Here, we report that inhibition of proteasome leads to elevated levels of PTF1a and to the existence of polyubiquitinated forms of PTF1a. We used the Sos recruitment system, an alternative two-hybrid system method to detect protein-protein interactions in the cytoplasm and to map the interactome of PTF1a. We identified TRIP12 (thyroid hormone receptor-interacting protein 12), an E3 ubiquitin-protein ligase as a new partner of PTF1a. We confirmed PTF1a/TRIP12 interaction in acinar cell lines and in co-transfected HEK-293T cells. The protein stability of PTF1a is significantly increased upon decreased expression of TRIP12. It is reduced upon overexpression of TRIP12 but not a catalytically inactive TRIP12-C1959A mutant. We identified a region of TRIP12 required for interaction and identified lysine 312 of PTF1a as essential for proteasomal degradation. We also demonstrate that TRIP12 down-regulates PTF1a transcriptional and antiproliferative activities. Our data suggest that an increase in TRIP12 expression can play a part in PTF1a down-regulation and indicate that PTF1a/TRIP12 functional interaction may regulate pancreatic epithelial cell homeostasis.

International audience; Pancreatic cancer is a public health problem because of its increasing incidence, the absence of early diagnostic tools, and its aggressiveness. Despite recent progress in chemotherapy, the 5-year survival rate remains below 5%. Liquid biopsies are of particular interest from a clinical point of view because they are non-invasive biomarkers released by primary tumours and metastases, remotely reflecting disease burden. Pilot studies have been conducted in pancreatic cancer patients evaluating the detection of circulating tumour cells, cell-free circulating tumour DNA, exosomes, and tumour-educated platelets. There is heterogeneity between the methods used to isolate circulating tumour elements as well as the targets used for their identification. Performances for the diagnosis of pancreatic cancer vary depending of the technique but also the stage of the disease: 30-50% of resectable tumours are positive and 50-100% are positive in locally advanced and/or metastatic cases. A significant prognostic value is demonstrated in 50-70% of clinical studies, irrespective of the type of liquid biopsy. Large prospective studies of homogeneous cohorts of patients are lacking. One way to improve diagnostic and prognostic performances would be to use a combined technological approach for the detection of circulating tumour cells, exosomes, and DNA.

KLF6 is ubiquitously expressed in human tissues and regulates many pathways such as differentiation, development, cellular proliferation, growth-related signal transduction, and apoptosis. We previously demonstrated that KLF6 expression is altered during liver carcinogenesis. More importantly, KLF6 invalidation results in cell cycle progression inhibition and apoptosis of liver cancer cells. On the other hand, enforced expression of KLF6 variant 2 (SV2) induces cancer cell death by apoptosis. Thus, we and others demonstrated that KLF6 and its splicing variants play a critical role in liver cancer. However, little is known on the mechanisms governing KLF6 expression in HCC. In the present work, we asked whether the 3' untranslated region (3'UTR) of the KLF6 mRNA may be responsible for regulation of KLF6 expression in HCC. We found that KLF6 mRNA stability was altered in liver-derived cell lines as compared to cervical cancer-derived cell lines and human embryonic fibroblasts. Interestingly, KLF6 mRNA was highly unstable in liver cancer-derived cell lines as compared to normal hepatocytes. We next cloned the KLF6 mRNA 3'UTR into luciferase-expressing vectors and found that gene expression and activity were strongly impaired in all liver-derived cell lines tested. In addition, we found that most the KLF6 3'UTR destabilisation activity resides between nt 1,835 and nt 2,615 of the KLF6 gene. Taken together, we provide the first steps towards better understanding of the regulation of KLF6 expression in HCC. Further work is needed to identify the factors that bind to KLF6 3'UTR to regulate its expression in liver cancer-derived cell lines.

La mutation ponctuelle de l’oncogene Kras confere un gain de proliferation non controlee pour la cellule cancereuse qui acquiert ainsi un pouvoir oncogenique amplifie. Cette mutation est retrouvee dans 75 a 95 % des cancers du pancreas, mais aussi dans les lesions precancereuses de type PanIN (pancreatic intraepithelial neoplasia ) ou TIPMP (tumeur intracanalaire papillaire mucineuse du pancreas). Ces lesions, ainsi que le microenvironnement tumoral, ont ete reproduits dans des modeles transgeniques etablis chez la souris a partir de la mutation de Kras (souris Pdx1 [pancreatic and duodenal homeobox 1 ]-Cre ; KrasG12D ) associee ou non a l’inactivation de genes suppresseurs de tumeurs (TP53, DPC4, INK4A ). La recherche de la mutation de Kras en clinique humaine est facile et fiable a partir des milieux biologiques, en particulier sur le materiel de cytoponction de masses pancreatiques preleve sous echo-endoscopie. Cette recherche devrait etre utile dans un avenir proche pour l’aide au diagnostic positif de cancer, en cas de d’examen cytopathologique douteux ou non contributif, mais aussi pour le diagnostic differentiel avec la pancreatite chronique dans sa forme pseudotumorale.

DNA methylation is a major epigenetic modification that is strongly involved in the physiological control of genome expression. DNA methylation patterns are largely modified in cancer cells and can therefore be used to distinguish cancer cells from normal tissues. This review describes the main technologies available for the detection and the discovery of aberrantly methylated DNA patterns. It also presents the different sources of biological samples suitable for DNA methylation studies. We discuss the interest and perspectives on the use of DNA methylation measurements for cancer diagnosis through examples of methylated genes commonly documented in the literature. The discussion leads to our consideration for why DNA methylation is not commonly used in clinical practice through an examination of the main requirements that constitute a reliable biomarker. Finally, we describe the main DNA methylation inhibitors currently used in clinical trials and those that exhibit promising results.

To date, pancreatic cancer (PDAC) can't be diagnosed early. Consequently, a majority of patient (80%) display an advanced disease that results in a low resection rate leading to an overall median survival of 4 to 6months. Accordingly, robust markers for the early diagnosis and prognosis of pancreatic cancer, or markers indicative of survival and/or metastatic disease are desperately needed to help alleviate the dismal prognosis of this disease. In this chapter, we review the translational studies demonstrating that miRNAs, alone or in combination, may soon translate into clinical applications as long-awaited screening tools for PDAC.

Despite tremendous efforts worldwide from clinicians and cancer scientists, pancreatic ductal adenocarcinoma (PDA) remains a deadly disease for which no cure is available. Recently, microRNAs (miRNAs) have emerged as key actors in carcinogenesis and we demonstrated that microRNA-21 (miR-21), oncomiR is expressed early during PDA. In the present study, we asked whether targeting miR-21 in human PDA-derived cell lines using lentiviral vectors (LVs) may impede tumor growth. We demonstrated that LVs-transduced human PDA efficiently downregulated miR-21 expression, both in vitro and in vivo. Consequently, cell proliferation was strongly inhibited and PDA-derived cell lines died by apoptosis through the mitochondrial pathway. In vivo, miR-21 depletion stopped the progression of a very aggressive model of PDA, to induce cell death by apoptosis; furthermore, combining miR-21 targeting and chemotherapeutic treatment provoked tumor regression. We demonstrate herein for the first time that targeting oncogenic miRNA strongly inhibit pancreatic cancer tumor growth both in vitro and in vivo. Because miR-21 is overexpressed in most human tumors; therapeutic delivery of miR-21 antagonists may still be beneficial for a large number of cancers for which no cure is available.

Since their discovery, microRNAs (miRNAs)20 have shown great promise in a wide array of clinical applications. In some cases, the use of miRNAs as new diagnostic markers might help answer diagnostic dilemmas that gene expression analyses or other types of analyses have not been able to satisfactorily address. In other instances, it is easy to perceive certain miRNAs as targets for novel therapies that downregulate an entire pathway via the targeting of a single miRNA. When and if this concept will come to fruition remain unclear. Scientists agree that this field of biology is exciting, offers much promise, and has numerous advantages, compared with experiences with other biomolecules. In this Q&A, 5 individuals with extensive miRNA experience share their vision for where the miRNA field is heading and whether we, in the clinical laboratory, will experience its implications soon. What are the most important characteristics of miRNAs that increase their potential as novel diagnostic or therapeutic targets? George Calin: One important characteristic of miRNAs that makes them an exciting potential biomarker for diagnosis and/or a target for therapy is the fact that specific miRNAs target multiple components from the same pathway. For example, the miR-15a/16–1 cluster targets genes from the apoptotic pathway: BCL2 21 (B-cell CLL/lymphoma 2) and MCL1 [myeloid cell leukemia sequence 1 ( BCL2 -related)]. Any given miRNA can regulate numerous genes, and each gene can be regulated by different miRNAs. Pierre Cordelier: In cancer research, miRNAs can differentiate normal from cancerous tissues and, more importantly, can discriminate different subtypes of cancer. The high stability of miRNAs in tissues and fluids is another key advantage that increases their potential as diagnostic markers over messenger RNA (mRNA). In addition, they can be quantified in very low amounts of material and in highly degraded samples. This is of prime importance …

International audience; Mutation of the KRAS oncogene in pancreatic cancer is responsible for permanent activation of the P21 RAS protein and the cascade of signalling pathways. Consequently, multiple cellular processes, such as transformation, proliferation, invasion, and survival are activated. The aim of this review was to present all potential clinical applications of targeting KRAS in terms of diagnosis and management of pancreatic adenocarcinoma. Quantitative polymerase chain reaction technology provides reliable assessment of KRAS mutations, both in tissues and from fine-needle aspiration biopsies. Numerous studies report that the combination of endoscopic ultrasound-guided cytopathology and a KRAS mutation assay can improve the positive and differential diagnosis of pancreatic cancer, differentiating between benign versus malignant solid pancreatic cancer, and reducing false-negative results compared to cytopathology alone. In addition, the presence of a KRAS mutation is frequently associated with a worse prognosis, both in cases of advanced and resected tumours. However, the KRAS mutation assay is not as efficient at predicting a response to both anti-epidermal growth factor receptor treatments and/or chemotherapy. Targeting of KRAS to treat pancreatic adenocarcinoma has been applied at different stages of RAS molecular intracellular processes: at the transcription level with antisense or interference RNA, at the posttranslational level with inhibitors of farnesyl transferase or anti-RAS vaccination peptides, and to target multiple signalling pathways using inhibitors of mitogen-activated protein kinase, phosphoinositide 3-kinase, AKT, mammalian target of rapamycin, RAF. Despite some encouraging results at pre-clinical and phase I stages, no significant clinical benefits have been observed. Combinatory approaches with standard chemotherapy will be welcome

The incidence of pancreatic cancer is increasing but the prognosis remains poor. The lack of clearly identified risk factors hinders screening and early diagnosis (when the disease is still curable). The sole curative treatment is surgical resection, which is feasible in only 15% of patients. Chemotherapy regimens are being developed in an attempt to prolong the survival of patients who do not quality for surgery. Recent advances include better knowledge and treatment of pre-neoplastic pancreatic lesions such as mucinous tumors. Basic and translational researchers are attempting to identify tumoral or circulating antigens that could serve as diagnostic markers and/or therapeutic targets.

Overexpression of growth differentiation factor 15 (GDF15) by bone marrow mesenchymal stem cells occurs widely in patients with multiple myeloma, but the pathophysiologic effects of GDF15 in this setting remain undefined. GDF15 has been described in numerous solid tumors but never in hematologic malignancies. In this study, we report that GDF15 significantly increases survival of stroma-dependent multiple myeloma cells including primary multiple myeloma cells. In particular, GDF15 conferred resistance to melphalan, bortezomib, and to a lesser extent, lenalidomide in both stroma-dependent and stroma-independent multiple myeloma cells. Akt-dependent signaling was critical to mediate the effects of GDF15, whereas Src and extracellular signal-regulated kinase 1/2 signaling pathways were not involved. Given these results, we tested the clinical significance of plasma concentrations of GDF15 (pGDF15) in 131 patients with multiple myeloma and found that it correlated with disease prognosis. Specifically, patients with high levels of pGDF15 had lower probabilities of event-free and overall survival 30 months after diagnosis than patients with low pGDF15 levels. Our findings suggest that tumor microenvironment-derived GDF15 is a key survival and chemoprotective factor for multiple myeloma cells, which is pathophysiologically linked to both initial parameters of the disease as well as patient survival. Cancer Res; 72(6); 1395–406. ©2012 AACR.

Endoscopic ultrasound-guided fine needle aspiration-biopsy is a safe and effective technique in diagnosing and staging of pancreatic ductal adenocarcinoma. However its predictive negative value does not exceed 50% to 60%. Unfortunately, the majority of pancreatic cancer patients have a metastatic and/or a locally advanced disease (i.e., not eligible for curative resection) which explains the limited access to pancreatic tissue specimens. Endoscopic ultrasound-guided fine needle aspiration-biopsy is the most widely used approach for cytological and histological material sampling in these situations used in up to two thirds of patients with pancreatic cancer. Based on this unique material, we and others developed strategies to improve the differential diagnosis between carcinoma and inflammatory pancreatic lesions by analysis of KRAS oncogene mutation, microRNA expression and methylation, as well as mRNA expression using both qRT-PCR and Low Density Array Taqman analysis. Indeed, differentiating pancreatic cancer from pseudotumoral chronic pancreatitis remains very difficult in current clinical practice, and endoscopic ultrasound-guided fine needle aspiration-biopsy analysis proved to be very helpful. In this review, we will compile the clinical and molecular advantages of using endoscopic ultrasound-guided fine needle aspiration-biopsy in managing pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Despite significant progresses in the last decades, the origin of this cancer remains unclear and no efficient therapy exists. PDAC does not arise de novo: three remarkable different types of pancreatic lesions can evolve towards pancreatic cancer. These precursor lesions include: Pancreatic intraepithelial neoplasia (PanIN) that are microscopic lesions of the pancreas, Intraductal Papillary Mucinous Neoplasms (IPMN) and Mucinous Cystic Neoplasms (MCN) that are both macroscopic lesions. However, the cellular origin of these lesions is still a matter of debate. Classically, neoplasm initiation or progression is driven by several genetic and epigenetic alterations. The aim of this review is to assemble the current information on genetic mutations and epigenetic disorders that affect genes during pancreatic carcinogenesis. We will further discuss the interest of the genetic and epigenetic alterations for the diagnosis and prognosis of PDAC. Large genetic alterations (chromosomal deletion/amplification) and single point mutations are well described for carcinogenesis inducers. Mutations classically occur within key regions of the genome. Consequences are various and include activation of mitogenic pathways or silencing of apoptotic processes. Alterations of K-RAS, P16 and DPC4 genes are frequently observed in PDAC samples and have been described to arise gradually during carcinogenesis. DNA methylation is an epigenetic process involved in imprinting and X chromosome inactivation. Alteration of DNA methylation patterns leads to deregulation of gene expression, in the absence of mutation. Both genetic and epigenetic events influence genes and non-coding RNA expression, with dramatic effects on proliferation, survival and invasion. Besides improvement in our fundamental understanding of PDAC development, highlighting the molecular alterations that occur in pancreatic carcinogenesis could provide new clinical tools for early diagnosis of PDAC and the molecular basis for the development of new effective therapies.

In the paper untitled “high-throughput creation and functional profiling of DNA sequence variant libraries using CRISP-Cas9 in yeast” (1) published online in May 2018 in Nature Biotechnology, George M. Church, an eminent expert in CRISPR-Cas9 biology and technology, makes, yet another, giant step in the field of genomics.

Background & Aims KLF6 protein is a transcription factor that plays important functions in hepatocellular carcinoma (HCC), which is one of the leading causes of death by cancer worldwide. Previous studies showed the existence of three splice variants of KLF6, termed SV1, SV2, and SV3. An increased SV1/KLF6 mRNA ratio in HCC was already described. In this study, we aimed to investigate the expression of the SV2 variant in HCC samples and its role in hepatic cells. Methods We measured the expression of the SV2 variant in HCC and adjacent tissue samples by q-RT-PCR. We established IHH and HepG2 stable cell lines over-expressing the SV2 variant and measured cell growth and apoptotic rate. Results We observed a reduced expression of the SV2 variant in HCC samples versus surrounding tissues and normal liver. Interestingly, our findings demonstrate that the over-expression of the SV2 variant in IHH and HepG2 cells leads to a significant reduction of proliferation associated with cell death by apoptosis. We further demonstrate that the SV2 expression leads to an induction of the cell-cycle-controlling p21 ( CIP/WAF1 ) and the pro-apoptotic Bax genes, mediated by the p53 protein. We show further that the SV2 expression in IHH and HepG2 cells induces their sensitivity to the anti-cancer drug, gemcitabine. Conclusion We reveal a reduced expression of the SV2 variant of KLF6 in HCC samples and describe anti-proliferative and pro-apoptotic functions for this variant in hepatic cells.

Background: Pancreatic ductal adenocarcinoma (PDAC) has the poorest overall prognosis among gastrointestinal cancers; however, curative resection in early-stage PDAC greatly improves survival rates, indicating the importance of early detection. Because abnormal microRNA production is commonly detected in cancer, we investigated noninvasive precursor pancreatic intraepithelial neoplasia (PanIN) lesions for microRNA production as a potential early biomarker of PDAC.Methods: Pathologists identified and classified ductal lesions. We extracted total RNA from laser-capture microdissected PanIN tissue samples from a conditional KRAS(G12D) mouse model (n = 29) or of human origin (n = 38) (KRAS is v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog). MicroRNA production was quantified by quantitative real-time PCR. Internal controls included 5S and U6 RNAs.Results: Production of microRNAs miR-21, miR-205, and miR-200 paralleled PanIN progression in the KRAS(G12D) mouse model, compared with microRNA production in samples of nonpathologic ducts. miR-21 demonstrated the highest relative concentrations in the precursor lesions. Interestingly, miR-205 and miR-21 up-regulation preceded phenotypic changes in the ducts. The production of microRNAs miR-21, miR-221, miR-222, and let-7a increased with human PanIN grade, with peak production occurring in hyperplastic PanIN-2/3 lesions. In situ hybridization analysis indicated miR-21 production to be concentrated in pathologic ductal cells. miR-21 production was regulated by KRAS(G12D) and epidermal growth factor receptor in PDAC-derived cell lines.Conclusions: Aberrant microRNA production is an early event in the development of PanIN. Our findings indicate that miR-21 warrants further investigation as a marker for early detection of PDAC.

International audience; BACKGROUND AND STUDY AIMS: Differential diagnosis between pancreatic adenocarcinoma (PADC) and pseudotumoral forms of chronic pancreatitis remains difficult. Mutation of KRAS oncogene is present in 75% to 95% of PADC. This study aimed to evaluate whether the combined analysis of KRAS mutation with cytopathological findings from endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) might improve discrimination between PADC and chronic pancreatitis. PATIENTS AND METHODS: This prospective multicenter study included 178 patients with solid pancreatic masses (men 104, women 74; mean age 64.5 years). Cytopathological examination and KRAS mutation analysis (codon-12 and codon-13, restriction fragment length polymorphism [RFLP] and direct sequencing) were performed on EUS-FNAB material. Final diagnoses were obtained on EUS-FNAB analysis and/or a second biopsy and/or clinical follow-up and/or surgery: PADC, n = 129; chronic pancreatitis, n = 27; other pancreatic neoplasms, n = 16; and benign lesions, n = 6. RESULTS: KRAS status analysis was successful in all EUS-FNAB samples. Codon-12 KRAS point mutation was found in 66% of PADC samples. No case of chronic pancreatitis displayed KRAS mutation. Sensitivity, specificity, positive and negative predictive values, and overall accuracy of cytopathology alone for diagnosis of PADC versus chronic pancreatitis were 83%, 100%, 100%, 56% and 86%, respectively. When KRAS mutation analysis was combined with cytopathology, these values reached 88%, 100%, 100%, 63% and 90% respectively. CONCLUSION: Although the value of KRAS analysis in addition to EUS-FNAB is limited for distinguishing pancreatic mass lesions, when chronic pancreatitis presented as a pseudotumor a negative finding (wild-type KRAS), was useful in strongly suggesting a benign lesion.

International audience; Somatostatin is a neuropeptide that inhibits exocrine and endocrine secretions of several hormones and negatively regulates cell proliferation. These events are mediated through somatostatin engagement on one of five G protein-coupled receptors named SSTR1 to STTR5. Somatostatin binding to SSTR2 mediates predominantly antisecretory and antiproliferative effects; two important biological activities in the gastroenteropancreatic endocrine and exocrine system. Herein we demonstrate novel regulatory sequences for human (h) SSTR2 transcription. By genomic DNA sequence analysis, we reveal two CpG islands located 3.8 kb upstream from the transcription start site. We identify a novel transcription start site and a promoter region within one of these CpG islands. We demonstrate that two epigenetic modifications, DNA methylation and histone acetylation, regulate the activation of hSSTR2 upstream promoter. Furthermore, we show that the transcription from this upstream promoter region directly correlates to hSSTR2 mRNA expression in various human cell lines. A combined treatment of a demethylating agent, 5-aza-2-deoxycytidine and a histone deacetylase inhibitor, trichostatin A, leads to increased expression of hSSTR2 mRNA in cell lines in which the CpG island is methylated. The epigenetic regulation of this promoter region results in differential expression of hSSTR2 mRNA in human cell lines. This study reveals the existence of a novel upstream promoter for the hSSTR2 gene that is regulated by epigenetic modifications, suggesting for complex control of the hSSTR2 transcription.

The vast majority (85%) of pancreatic ductal adenocarcinomas (PDACs) are discovered at too of a late stage to allow curative surgery. In addition, PDAC is highly resistant to conventional methods of chemotherapy and radiotherapy, which only offer a marginal clinical benefit. Consequently, the prognosis of this cancer is devastating, with a 5-year survival rate of less than 5%. In this dismal context, we recently demonstrated that PDAC gene therapy using nonviral vectors is safe and feasible, with early signs of efficacy in selected patients. Our next step is to transfer to the clinic HIV-1-based lentiviral vectors (LVs) that outshine other therapeutic vectors to treat experimental models of PDAC. However, a primary safety issue presented by LVs that may delay their use in patients is the risk of oncogenesis after vector integration in the host's cell DNA. Thus, we developed a novel anticancerous approach based on integrase-defective lentiviral vectors (IDLVs) and demonstrated that IDLVs can be successfully engineered to transiently deliver therapeutic genes to inhibit pancreatic cancer cells proliferation. This work stems for the use of therapeutic IDLVs for the management of PDAC, in forthcoming early phase gene therapy clinical trial for this disease with no cure.

International audience; OBJECTIVES: There is no molecular biomarker available in the clinical practice to assess the prognosis of advanced pancreatic carcinoma. This multicenter prospective study aimed to investigate the role of KRAS mutation subtypes within the primary tumor to determine the prognosis of advanced pancreatic cancer. METHODS: The exon-2 KRAS mutation status was tested on endoscopic ultrasound-guided fine-needle aspiration biopsy material (primary tumor; restriction fragment-length polymorphism plus sequencing and TaqMan allelic discrimination) of patients with proven locally advanced and/or metastatic pancreatic ductal carcinoma. We used the Kaplan-Meier method, log-rank test, and Cox's model to evaluate the impact of KRAS status on the overall survival (OS), adjusting for age, stage of disease, clinical performance status, CA 19-9 levels, and treatment. RESULTS: A total of 219 patients (men: 116; mean age: 67±9.4 years) were included: 147 harbored a codon-12 KRAS mutation (G12D: 73; G12V: 53; G12R: 21) and 72 had a wild-type KRAS. There was no difference in the OS between patients with a mutant KRAS (8 months; 95% confidence interval (95% CI): 8.7-12.3) and the wild-type (9 months; 95% CI: 8.7-12.8; hazard ratio (HR): 1.03; P=0.82). However, the patients with a G12D mutation had a significantly shorter OS (6 months; 95% CI: 6.4-9.7) compared with the other patients (OS: 9 months; 95% CI: 10-13; HR: 1.47; P=0.003; i.e., wild type: 9 months, G12V: 9 months, G12R: 14 months). Similar results were observed in the subgroup of 162 patients who received chemotherapy (HR: 1.66; P=0.0013; G12D (n=49): 8 months, wild type (n=56): 10 months, G12V (n=38): 10 months, G12R (n=19): 14 months). Multivariate analyses identified KRAS G12D as an independent predictor for worse prognosis within the entire series (HR: 1.44; P=0.01) and in the subgroup of patients that received chemotherapy (HR: 1.84; P=0.02). CONCLUSIONS: The KRAS G12D mutation subtype is an independent prognostic marker for advanced pancreatic ductal carcinoma. Codon and amino-acid-specific mutations of KRAS should be considered when evaluating the prognoses as well as in trials testing drugs that target RAS and downstream RAS pathways

Since the last decade improvements in high-throughput sequencing apparatuses and bioinformatic softwares has allowed for better quantitative analysis of noncoding RNAs (ncRNAs). While long neglected, the interest in ncRNAs by scientific communities is rising given that they represent 60% of total RNA. Their functions, which in some cases involve complex molecular mechanisms, are progressively being understood. Though one class of ncRNAs can act using different actions, most display the ability to control gene expression without affecting the DNA sequence. Therefore they constitute a major class of epigenetic regulators. Moreover, ncRNA expression profiles were demonstrated as valuable biomarkers in various human pathologies, and this has intensified the interest in ncRNAs by pharmaceutical industries and biotechnology companies. Thus the targeting of ncRNA species has become a promising therapeutic approach for the treatment of human pathologies such as cancer. In this chapter we will provide an overview of the biogenesis and mode of action of the different classes of ncRNAs. Data concerning the modulation of ncRNA expression in human diseases will be presented, as well as their potential as biomarkers. Finally, our attention will be focused on the therapeutic strategies developed to target ncRNAs in human disorders.

International audience; Unlike other digestive-cancer entities, chemotherapy, radiotherapy and targeted therapies have, so far, largely failed to improve patient survival in pancreatic adenocarcinoma (PDAC), which remains the fourth leading cause of cancer-related death in Europe and the United States. In this context, gene therapy may offer a new avenue for PDAC patients. In this review, we explore the research currently ongoing in French laboratories aimed at defeating PDAC using non-viral therapeutic gene delivery, targeted transgene expression or oncolytic virotherapy that recently or will soon bridge the gap between experimental models of cancer and clinical trials. These studies are likely to change clinical practice or thinking about PDAC management, as they represent a major advance not only for PDAC and may also largely influence the field of gene-based molecular treatment of cancer.

Poster session 1 New tools and technologies: Gene and genome editing and engineering ref: Article Prodinra 362187; International audience; Widespread application of gene therapy will depend on the development of simple methods to regulate the expression of therapeutic genes. Here we harness an endogenous signaling pathway to regulate therapeutic gene expression through diet. The GCN2-eIF2α signaling pathway is specifically activated by deficiencies in any essential amino acid (EAA); EAA deficiency leads to rapid expression of genes regulated by ATF4-binding cis elements. We found that therapeutic genes under the control of optimized amino acid response elements (AAREs) had low basal expression and high induced expression. We applied our system to regulate the expression of TNFSF10 (TRAIL) in the context of glioma therapy and found that intermittent activation of this gene by EEA-deficient meals retained its therapeutic efficacy while abrogating its toxic effects on normal tissue. The GCN2-eIF2α pathway is expressed in many tissues, including the brain, and is highly specific to EAA deficiency. Our system may be particularly well suited for intermittent regulation of therapeutic transgenes over short or long time periods

Background and Aims: Macronodules (MN) occurring in cirrhosis are considered to be precursor lesions for hepatocellular carcinoma (HCC). However, early molecular events in hepatocellular carcinogenesis are poorly understood. The aim of this study was to compare gene expression profiling between cirrhotic tissues, MN, and HCC, to identify genes early involved in liver carcinogenesis. Methods: Tissues were obtained from explanted livers: nine cirrhosis, 10 MN, and seven HCC. Total RNAs were extracted by RNeasy and reverse transcribed with labelled [33P]-αATP. Hybridations were performed on Atlas Human Cancer 1.2 membranes (1176 genes). Results: A two-way hierarchical clustering algorithm successfully isolated specific gene expression profiles when comparing MN, cirrhosis, and HCC. A total of 16 and 14 genes were up- and down-expressed, respectively, in HCC as compared to cirrhotic tissues. The molecular signature of MN was characterized by the down-expression of 23 and 42 genes as compared to cirrhosis and HCC, respectively. Among them, Klf6 was down-expressed in all MN samples whereas it was over-expressed in cirrhosis and HCC. This result was confirmed at RNA level by quantitative real time–polymerase chain reaction and at protein level by Western blotting. However, no mutation in the exon 2 of Klf6 was detected. Conclusion: We identified a molecular signature of MN characterized by a down-expression of several genes. One of them, Klf6 was found to be down-expressed in all MN without evidence of somatic mutations in the exon 2. This gene could be involved at an early stage of hepatocarcinogenesis.

Peritoneal carcinomatosis from pancreatic cancer has a poor prognosis with a median survival of 3.1 months. This is mainly due to lack of effective treatment. Interleukin 12 (IL12) is a proinflammatory cytokine that has a potent antitumoral effect by stimulating innate and adoptive immunity.To examine the antitumoral effect and toxicity of intraperitoneal delivery of IL12 using an ex vivo gene therapy approach in a murine model of pancreatic peritoneal carcinomatosis.Peritoneal carcinomatosis was generated by direct intraperitoneal inoculation of the pancreatic cancer cell line Capan-1 in athymic mice. Syngenic fibroblasts were genetically modified in vitro to secrete IL12 using a polycistronic TFG murine IL12 retroviral vector coding for both p35 and p40 murine IL12 subunits. Ex vivo gene therapy involved injection of the genetically modified fibroblasts intraperitoneally twice a week for 4 weeks.Treatment of pre-established peritoneal carcinomatosis with fibroblasts genetically modified to express IL12 induced a marked inhibition of tumour growth as measured by comparison of the weights of the intraperitoneal tumour nodules in the treated and control animals (3.52 (SD 0.47) v 0.93 (SD 0.21) g, p0.05) and improved survival. This effect was associated with infiltration of the peritoneal tumour nodules with macrophages. Peritoneal lavage confirmed enhancement of the innate peritoneal inflammatory activity, with an increased number of activated macrophages and natural killer cells. Moreover, macrophages harvested from animals with peritoneal carcinomatosis and treated with IL12-expressing fibroblasts expressed an activated proinflammatory antitumoral M1 phenotype that included strongly enhanced reactive oxygen species and nitric oxide production. There was no treatment-related toxicity.Multiple injections of genetically modified fibroblasts to express IL12 is an effective and well-tolerated treatment for experimental murine pancreatic peritoneal carcinomatosis via activated innate immunity and in particular activated M1 macrophages.

The understanding of the biology of pancreatic carcinoma has greatly benefited from studies of genetic/epigenetic alterations and molecular expression in experimental models as well as precancerous and cancerous tissues by mean of molecular amplification and large-scale transcriptoma analysis. P16, TP53, DPC4/Smad4 tumor suppressor pathways are genetically inactivated in the majority of pancreatic carcinomas, whereas oncogenic k-ras is activated. The activating point mutation of the KRAS oncogene on codon 12 is the major event and occurs early in pancreatic carcinogenesis. At a late stage of tumor development, an increase of telomerase activity, an over expression of growth factors and/or their receptors (EGF, Nerve Growth Factor, gastrin), of pro-angiogenic factors (VEGF, FGF, PDGF), of invasiveness factors (metalloproteinases, tissue plasminogen activators) occurs. The microenvironment plays also a key role in the invasive and metastatic process of pancreatic carcinoma with a strong relationship between cancerous cells and pancreatic stellate cells as well as extracellular matrix. This microenvironment strongly participates to the tumor fibrosis, hypoxia and hypovascularization inducing an inaccessibility of drugs. Nowadays, the targeting of microenvironment takes a special place in the new therapeutic strategies of pancreatic cancer in combination with chemotherapy.

Antiretroviral chemotherapy penetrates the CNS poorly. CNS HIV, thus sheltered, may injure the brain and complicate control of systemic HIV infection. Microglial cells play a major role in HIV persistence in the CNS but are rarely targeted for gene delivery. Because recombinant SV40 vectors (rSV40s) transduce other phagocytic cells efficiently, we tested rSV40 delivery of anti-HIV genetic therapy to microglial cells. Microglia prepared as enriched cultures from human fetal brain, were transduced with marker vectors, SV(RFP) and SV(Nef/FLAG), respectively, carrying DsRed and HIV-1 Nef bearing a FLAG epitope. By immunostaining and FACS, 95% of unselected cells expressed the transgenes, without detectable toxicity. Microglia were transduced with SV(AT), carrying human alpha1-antitrypsin (alpha1AT), which blocks Env and Gag processing. SV(AT)-treated microglia strongly resisted challenge with HIV-1BaL, even when microglia were transduced with SV(AT) following HIV challenge. Thus, rSV40s effectively transduce microglia and protect them from HIV.

Pancreatic cancer is one of the most aggressive and devastating human malignancies. The present study was conducted to determine whether in vivo sst2 gene transfer into human pancreatic tumors would impair tumor progression, and to characterize sst2 antitumoral bystander mechanisms. sst2 administration, using the synthetic vector PEI, strongly inhibited tumor progression of human pancreatic adenocarcinoma, in vivo. sst2 gene transfer induced intratumoral production of its ligand somatostatin. Disruption of this autocrine loop by RNA interference completely reversed sst2 antitumoral activity. Mice depleted of natural killer (NK) cells did not hamper sst2 tumor growth inhibition. However, microvessel density and vascular endothelial growth factor (VEGF) expression were markedly reduced in sst2-transfected tumors, whereas sst3 somatostatin receptor was upregulated. Depleting somatostatin by RNA interference completely abolished the sst2 inhibitory effect on VEGF expression and tumor angiogenesis, and sst2-induced sst3 expression in peripheral tumor vessels. We conclude that in vivo sst2 gene transfer elicited intratumoral somatostatin production and strongly impaired human pancreatic tumor growth. NK cells were not involved in this antitumoral bystander effect. VEGF and tumor vascularization were identified as novel targets for sst2-mediated antitumoral bystander effect. sst3 somatostatin receptor was upregulated in sst2-transfected tumors. Therefore, in vivo gene delivery of sst2 receptor to target the angiogenic process in pancreatic ductal adenocarcinoma might be a new therapeutic approach for treatment of pancreatic cancer in patients with unresectable disease.

The natural function of viruses is to deliver their genetic material to cells. Among the most effective of viruses in doing that is Simian Virus-40 (SV40). The properties that make SV40 a successful virus make it an attractive candidate for use as a gene delivery vehicle: high titer replication, infectivity for almost all nucleated cell types whether the cells are dividing or resting, potential for integration into cellular DNA, a peculiar pathway for entering cells that bypasses the cells' antigen processing apparatus, very high stability, and the apparent ability to activate expression of its own capsid genes in trans. Exploiting these and other characteristics of wild type (wt) SV40, increasing numbers of laboratories are studying recombinant (r) SV40-derived vectors. Among the uses to which these vectors have been applied are: delivering therapy to inhibit HIV, hepatitis C virus (HCV) and other viruses; correction of inherited hepatic and other protein deficiencies; immunizing against lentiviral and other antigens; treatment of inherited and acquired diseases of the central nervous system; protecting the lung and other organs from free radical-induced injury; and many others. The effectiveness of these vectors is a reflection of the adaptive evolution that produced their parent virus, wt SV40. This article explores how and why these vectors work, their strengths and their limitations, and provides a functional model for their exploitation for experimental and clinical applications.

In human immunodeficiency virus type 1 (HIV-1)-infected individuals, virus-induced production of interferon alpha (IFN-alpha) is impaired. In order to obtain regulated expression of IFN-alpha that responds to HIV-1 infection, a recombinant SV40 vector was designed that carries the human IFN-alpha2 cDNA under the control of the HIV-1 long terminal repeat (LTR) (SV[HIVLTR]IFN). Thus, the IFN-alpha2 gene would be trans-activated on infection with HIV-1. This vector was tested to determine if central nervous system (CNS) cell types that may be potential HIV-1 targets could be transduced and protected from HIV. SV[HIVLTR]IFN transduced NT2 cells, a human neuronal precursor cell line, mature neurons derived from NT2 precursor cells, and human primary monocyte-derived macrophages. IFN-alpha2 expression was retained in mature neurons after SV[HIVLTR]IFN-transduced NT2 precursor cells were induced to differentiate using retinoic acid. IFN-alpha expression was detected only after exposing transduced cells to HIV. Furthermore, SV[HIVLTR]IFN-delivered IFN-alpha2 expression significantly inhibited replication of multiple strains of HIV in both NT2 and NT2-derived mature neurons. SV[HIVLTR]IFN transduction also inhibited HIV-1(BaL) replication in human primary monocyte-derived macrophages. Therefore, we have demonstrated the effectiveness of IFN-alpha2, delivered by an SV40 vector driven by HIV-1 LTR as a promoter, to protect several CNS-based, potentially HIV-susceptible cell types. These findings may have implications for therapy of HIV-1 infection in the CNS.

Progress in gene therapy of human immunodeficiency virus (HIV) infection from laboratory to bedside, as for gene therapy in general, has been slow. Many transgenes, some very innovative, have been shown to inhibit HIV in cultured cells. But translation of such results to humans, or even to animal models of acquired immunodeficiency syndrome (AIDS), has been problematic. Among the reasons for this failure is ineffective gene delivery. Most gene delivery systems used for this purpose are limited by low production titers, fragility, poor transduction efficiency, waning transgene expression over time, requirements for ex vivo manipulation of target cells that constrain key aspects of these cells' utility on reimplantation, etc. These restrictions both prevent successful anti-HIV gene therapy and limit the scope of ideas as to how anti-HIV gene therapy may be used. Application of recombinant gene delivery vectors derived from simian virus-40 (rSV40s) may help to address many of these problems: 1. They transduce all HIV-susceptible cell types (lymphocytes, monocytes, dendritic cells, neurons, microglia, etc.) and their progenitors (e.g., CD34+ cells) with >95% efficiency without selection, whether as cell lines or as primary cells, resting or dividing; 2. Transgenes targeting almost every phase of the HIV-1 replicative cycle, from cell entry to virion morphogenesis have been delivered using these vectors. Individual transgenes vary in their abilities to inhibit HIV, but all do so. 3. Strains of HIV-1 inhibited by rSV40 gene delivery include laboratory and clinical isolates, X4-, R5- and dual-tropic viruses, and neurotropic strains (including CD4-independent HIV-1). 4. High transduction efficiency allows sequential transduction with multiple different rSV40s. Nearly all unselected cells treated with two different rSV40s are transduced by both. Combinations of transgenes provide far greater protection than any transgene individually. 5. Vector deoxyribonucleic acids (DNAs) integrate rapidly into the cellular DNA, assuring permanent transduction. Transgene expression has not diminished with time. 6. When severe combined immunodeficiency (SCID)-hu mice carrying implanted human tissues were transduced with a rSV40 vector in vivo, and then challenged with HIV in vivo, it provided the first demonstration that in vivo gene transfer with rSV40 vectors can inhibit HIV in vivo. 7. These vectors are safe. Although this gene delivery system has limitations (transgenes must be smaller than 5 kb; some common nonvertebrate marker genes like green fluorescent protein are not expressed well), it has strong advantages for application to AIDS gene therapy. The development rSV40 vectors and their application to treating HIV infection may facilitate the translation of AIDS gene therapy from a laboratory curiosity to a therapeutic tool.

Several lines of evidence suggest a potential major role for interferon (IFN) in controlling HIV-1 replication. However, this inhibition is moderate and is reversible upon IFN removal. To achieve prolonged high concentrations of IFN at the site of infection, we devised an SV40-based vector, SV[HIVLTR]IFN, to direct the synthesis of human IFN-alpha2, by employing a virus-trans-activated human IFN-alpha2 gene to be transcribed in response to HIV-1 infection. Expression of IFN-alpha2 was confirmed by Northern and Western blotting, in SV[HIVLTR]IFN-transduced, HIV-1-challenged human lymphocyte lines and primary human lymphocytes. SV[HIVLTR]IFN-transduced cells showed no evidence of HIV-1-related cytophatic effects when challenged with high doses of HIV-1(NL4-3). As measured by supernatant HIV-1 p24 antigen concentration, IFN-alpha2-expressing cell lines and peripheral blood lymphocytes (PBL) were protected from high-dose challenges of HIV-1. rSV40-delivered IFN-alpha2 inhibited gp120 protein synthesis and expression of HIV-1 mRNAs. Finally, Southern analysis revealed that levels of proviral DNA were markedly reduced in SV[HIVLTR]IFN-transduced cells compared to control cultures. IFN-alpha2 expression driven by HIVLTR delivered by an rSV40 vector thus strongly inhibits HIV-1 replication, probably by blocking a preintegration step in HIV-1 infection. Targeted expression of IFN-alpha2 delivered by SV40 can thus repress HIV-1 replication, and may be a useful approach to HIV-1 treatment.

Background Pancreatic cancer is the fourth leading cause of cancer death in Western countries, with the lowest 1-year survival rate among commonly diagnosed cancers. Reliable biomarkers for pancreatic cancer diagnosis are lacking and are urgently needed to allow for curative surgery. As microRNA (miRNA) recently emerged as candidate biomarkers for this disease, we explored in the present pilot study the differences in salivary microRNA profiles between patients with pancreatic tumors that are not eligible for surgery, precancerous lesions, inflammatory disease or cancer-free patients as a potential early diagnostic tool. Methods Whole saliva samples from patients with pancreatic cancer (n = 7), pancreatitis (n = 4), IPMN (n = 2), or healthy controls (n = 4) were obtained during endoscopic examination. After total RNA isolation, expression of 94 candidate miRNAs was screened by q(RT)PCR using Biomark Fluidgm. Human-derived pancreatic cancer cells were xenografted in athymic mice as an experimental model of pancreatic cancer. Results We identified hsa-miR-21, hsa-miR-23a, hsa-miR-23b and miR-29c as being significantly upregulated in saliva of pancreatic cancer patients compared to control, showing sensitivities of 71.4%, 85.7%, 85,7% and 57%, respectively and excellent specificity (100%). Interestingly, hsa-miR-23a and hsa-miR23b are overexpressed in the saliva of patients with pancreatic cancer precursor lesions. We found that hsa-miR-210 and let-7c are overexpressed in the saliva of patients with pancreatitis as compared to the control group, with sensitivity of 100% and 75%, and specificity of 100% and 80%, respectively. Last hsa-miR-216 was upregulated in cancer patients as compared to patients diagnosed with pancreatitis, with sensitivity of 50% and specificity of 100%. In experimental models of PDAC, salivary microRNA detection precedes systemic detection of cancer cells markers. Conclusions Our novel findings indicate that salivary miRNA are discriminatory in pancreatic cancer patients that are not eligible for surgery. In addition, we demonstrate in experimental models that salivary miRNA detection precedes systemic detection of cancer cells markers. This study stems for the use of salivary miRNA as biomarker for the early diagnosis of patients with unresectable pancreatic cancer.

As many other cancers, pancreatic ductal adenocarcinoma (PDAC) progression is associated with a series of hallmark changes for cancer cells to secure their own growth success. Yet, these very changes render cancer cells highly sensitive to viral infection. A promising strategy may rely on and exploit viral replication for tumor destruction, whereby infection of tumor cells by a replication-conditional virus may lead to cell destruction and simultaneous release of progeny particles that can spread and infect adjacent tumor cells, while sparing healthy tissues. In the present study, we used Myb34.5, a second-generation replication-conditional herpes simplex virus type 1 (HSV-1) mutant in which ICP6 gene expression is defective and expression of the HSV-1 γ134.5 gene is regulated by the cellular B-myb promoter. We found that B-myb is present in experimental PDAC and tumors, and is overexpressed in patients' tumors, as compared with normal adjacent pancreas. Myb34.5 replicates to high level in human PDAC cell lines and is associated with cell death by apoptosis. In experimental models of PDAC, mice receiving intratumoral Myb34.5 injections appeared healthy and tumor progression was inhibited, with evidence of tumor necrosis, hemorrhage, viral replication, and cancer cell death by apoptosis. Combining standard-of-care chemotherapy with Myb34.5 successfully led to a very impressive antitumoral effect that is rarely achieved in this experimental model, and resulted in a greater reduction in tumor growth than chemotherapy alone. These promising results warrant further evaluation in early phase clinical trial for patients diagnosed with PDAC for whom no effective treatment is available.

Despite tremendous efforts from scientists and clinicians worldwide, pancreatic adenocarcinoma (PDAC) remains a deadly disease due to the lack of early diagnostic tools and reliable therapeutic approaches. Consequently, a majority of patients (80%) display an advanced disease that results in a low resection rate leading to an overall median survival of less than 6 months. Accordingly, robust markers for the early diagnosis and prognosis of pancreatic cancer, or markers indicative of survival and/or metastatic disease are desperately needed to help alleviate the dismal prognosis of this cancer. In addition, the discovery of new therapeutic targets is mandatory to design effective treatments. In this review, we will highlight the translational studies demonstrating that microRNAs may soon translate into clinical applications as long-awaited screening tools and therapeutic targets for PDAC.