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Pancreatic cancer is a rare but lethal cancer due to its biologically aggressive nature, advanced stage at the time of diagnosis, and poor response to oncologic therapies. The risk of pancreatic cancer is significantly higher to 5% in certain high-risk individuals with inherited genetic susceptibility. Screening for pancreatic cancer in these individuals from high-risk groups can help with the early detection of pancreatic cancer as well as the detection of precursor lesions leading to early surgical resection and improved overall outcomes. The advancements in radiological imaging as well as advanced endoscopic procedures has made a significant impact on the early diagnosis, surveillance, and staging of pancreatic cancer. There is also a significant advancement in the development of biomarkers for the early detection of pancreatic cancer, which has also led to the development of liquid biopsy, allowing for microRNA detection in serum and circulating tumor cells. Various societies and organizations have provided guidelines for pancreatic cancer screening and surveillance in high-risk individuals. In this review, we aim to discuss the hereditary risk factors for developing pancreatic cancer, summarize the screening recommendations by different societies, and discuss the development of novel biomarkers and areas for future research in pancreatic cancer screening for high-risk individuals. [ABSTRACT FROM AUTHOR]

Despite substantial improvements in survival rates for most cancers, pancreatic cancer still remains a leading cause of death from malignancy. The disease has no symptoms in the initial stages, it can early invade the surrounding organs, and treatment methods have poor long-term prognosis. In addition, this neoplasia is starting to be diagnosed more and more frequently in young people. High incidences have been found in developed regions such as Europe, North America, Australia, but recent data show that this condition is increasing in other regions as well. Pancreatic cancer involves multiple factors such as cigarette smoking, obesity, diabetes, alcohol consumption, inherited genetic factors, recent studies also correlating pancreatic cancer with abnormal metabolism of human microorganisms, blood type, as well as glucose and lipid levels. This review aims to update knowledge on the epidemiology, pathophysiology, diagnosis and treatment of pancreatic cancer. The goal is to encourage screening and early diagnosis methods, as well as to stimulate further research on this oncological topic, insufficiently studied to date. [ABSTRACT FROM AUTHOR]

Pancreatic cancer (PC) is a dangerous digestive tract tumor that is becoming increasingly common and fatal. The most common form of PC is pancreatic ductal adenocarcinoma (PDAC). Bile acids (BAs) are closely linked to the growth and progression of PC. They can change the intestinal flora, increasing intestinal permeability and allowing gut microbes to enter the bloodstream, leading to chronic inflammation. High dietary lipids can increase BA secretion into the duodenum and fecal BA levels. BAs can cause genetic mutations, mitochondrial dysfunction, abnormal activation of intracellular trypsin, cytoskeletal damage, activation of NF-κB, acute pancreatitis, cell injury, and cell necrosis. They can act on different types of pancreatic cells and receptors, altering Ca2+ and iron levels, and related signals. Elevated levels of Ca2+ and iron are associated with cell necrosis and ferroptosis. Bile reflux into the pancreatic ducts can speed up the kinetics of epithelial cells, promoting the development of pancreatic intraductal papillary carcinoma. BAs can cause the enormous secretion of Glucagon-like peptide-1 (GLP-1), leading to the proliferation of pancreatic β-cells. Using Glucagon-like peptide-1 receptor agonist (GLP-1RA) increases the risk of pancreatitis and PC. Therefore, our objective was to explore various studies and thoroughly examine the role of BAs in PC. [ABSTRACT FROM AUTHOR]

Background: The purinergic P2X7 receptor (P2X7R) plays an important role in the crosstalk between pancreatic stellate cells (PSCs) and cancer cells, thus promoting progression of pancreatic ductal adenocarcinoma (PDAC). Single nucleotide polymorphisms (SNPs) in the P2X7R have been reported for several cancers, but have not been explored in PDAC. Materials and methods: Blood samples from PDAC patients and controls were genotyped for 11 non-synonymous SNPs in P2X7R and a risk analysis was performed. Relevant P2X7R-SNP GFP variants were expressed in PSCs and cancer cells and their function was assayed in the following tests. Responses in Ca2+ were studied with Fura-2 and dye uptake with YO-PRO-1. Cell migration was monitored by fluorescence microscopy. Released cytokines were measured with MSD assay. Results: Risk analysis showed that two SNPs 474G>A and 853G>A (rs28360447, rs7958316), that lead to the Gly150Arg and Arg276His variants, had a significant but opposite risk association with PDAC development, protecting against and predisposing to the disease, respectively. In vitro experiments performed on cancer cells and PSCs expressing the Gly150Arg variant showed reduced intracellular Ca2+ response, fluorescent dye uptake, and cell migration, while the Arg276His variant reduced dye uptake but displayed WT-like Ca2+ responses. As predicted, P2X7R was involved in cytokine release (IL-6, IL-1β, IL-8, TNF-α), but the P2X7R inhibitors displayed varied effects. Conclusion: In conclusion, we provide evidence for the P2X7R SNPs association with PDAC and propose that they could be considered as potential biomarkers. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is a highly lethal disease with a 5-year survival rate of around 11–12%. Surgery, being the treatment of choice, is only possible in 20% of symptomatic patients. The main reason is that when it becomes symptomatic, IT IS the tumor is usually locally advanced and/or has metastasized to distant organs; thus, early diagnosis is infrequent. The lack of specific early symptoms is an important cause of late diagnosis. Unfortunately, diagnostic tumor markers become positive at a late stage, and there is a lack of early-stage markers. Surgical and non-surgical cases are treated with neoadjuvant and/or adjuvant chemotherapy, and the results are usually poor. However, personalized targeted therapy directed against tumor drivers may improve this situation. Until recently, many pancreatic tumor driver genes/proteins were considered untargetable. Chemical and physical characteristics of mutated KRAS are a formidable challenge to overcome. This situation is slowly changing. For the first time, there are candidate drugs that can target the main driver gene of pancreatic cancer: KRAS. Indeed, KRAS inhibition has been clinically achieved in lung cancer and, at the pre-clinical level, in pancreatic cancer as well. This will probably change the very poor outlook for this disease. This paper reviews the genetic characteristics of sporadic and hereditary predisposition to pancreatic cancer and the possibilities of a personalized treatment according to the genetic signature. [ABSTRACT FROM AUTHOR]

Clostridium novyi has demonstrated selective efficacy against solid tumors largely due to the microenvironment contained within dense tumor cores. The core of a solid tumor is typically hypoxic, acidic, and necrotic—impeding the penetration of current therapeutics. C. novyi is attracted to the tumor microenvironment and once there, can both lyse and proliferate while simultaneously re-activating the suppressed immune system. C. novyi systemic toxicity is easily mitigated by knocking out the phage DNA plasmid encoded alpha toxin resulting in C. novyi-NT; but, after intravenous injection spores are quickly cleared by phagocytosis before accomplishing significant tumor localization. C. novyi-NT could be designed to accomplish intravenous delivery with the potential to target all solid tumors and their metastases in a single dose. This study characterizes CRISPR/Cas9 modified C. novyi-NT to insert the gene for RGD, a tumor targeting peptide, expressed within the promoter region of a spore coat protein. Expression of the RGD peptide on the outer spore coat of C. novyi-NT indicates an increased capacity for tumor localization of C. novyi upon intravenous introduction based on the natural binding of RGD with the αvβ3 integrin commonly overexpressed on the epithelial tissue surrounding a tumor, and lead to immune stimulation. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers worldwide, mainly due to its late diagnosis and lack of effective therapies, translating into a low 5-year 12% survival rate, despite extensive clinical efforts to improve outcomes. International cooperative studies have provided informative multiomic landscapes of PDAC, but translation of these discoveries into clinical advances are lagging. Likewise, early diagnosis biomarkers and new therapeutic tools are sorely needed to tackle this cancer. The study of poorly explored molecular processes, such as splicing, can provide new tools in this regard. Alternative splicing of pre-RNA allows the generation of multiple RNA variants from a single gene and thereby contributes to fundamental biological processes by finely tuning gene expression. However, alterations in alternative splicing are linked to many diseases, and particularly to cancer, where it can contribute to tumor initiation, progression, metastasis and drug resistance. Splicing defects are increasingly being associated with PDAC, including both mutations or dysregulation of components of the splicing machinery and associated factors, and altered expression of specific relevant gene variants. Such disruptions can be a key element enhancing pancreatic tumor progression or metastasis, while they can also provide suitable tools to identify potential candidate biomarkers and discover new actionable targets. In this review, we aimed to summarize the current information about dysregulation of splicing-related elements and aberrant splicing isoforms in PDAC, and to describe their relationship with the development, progression and/or aggressiveness of this dismal cancer, as well as their potential as therapeutic tools and targets. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer incidence is increasing yearly. The reasons are not well known. Unfortunately, this is one of the least treatable cancers. Standard chemotherapy treatments show poor results, as do targeted treatments. The only real improvement in pancreatic cancer in the last twenty years occurred in the surgical field, where neoadjuvant therapy and very early surgery have achieved better overall survival. The only secret of arriving early to surgery is early diagnosis, and the missing element for early diagnosis is screening. This paper discusses the population that needs to be screened. Pancreatic ductal adenocarcinoma has a very high mortality rate which has been only minimally improved in the last 30 years. This high mortality is closely related to late diagnosis, which is usually made when the tumor is large and has extensively infiltrated neighboring tissues or distant metastases are already present. This is a paradoxical situation for a tumor that requires nearly 15 years to develop since the first founding mutation. Response to chemotherapy under such late circumstances is poor, resistance is frequent, and prolongation of survival is almost negligible. Early surgery has been, and still is, the only approach with a slightly better outcome. Unfortunately, the relapse percentage after surgery is still very high. In fact, early surgery clearly requires early diagnosis. Despite all the advances in diagnostic methods, the available tools for improving these results are scarce. Serum tumor markers permit a late diagnosis, but their contribution to an improved therapeutic result is very limited. On the other hand, effective screening methods for high-risk populations have not been fully developed as yet. This paper discusses the difficulties of early diagnosis, evaluates whether the available diagnostic tools are adequate, and proposes some simple and not-so-simple measures to improve it. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer is a very deadly form of cancer with a low survival rate. One important characteristic of pancreatic cancer is the presence of a dense tissue called desmoplastic stroma, which creates an environment that promotes tumor growth. Within this environment, there are specialized cells called cancer-associated fibroblasts (CAFs) that play a crucial role. They are a diverse group of cells with different functions and surface markers. When activated, CAFs support the invasion, spread, and growth of cancer cells, as well as affect the immune system. Scientists have been studying how CAFs interact with cancer cells and immune cells to understand how they contribute to tumor growth and spread. However, there is still a lot we do not know about CAFs and their role in pancreatic cancer. Further research is needed to better understand CAFs and their impact on the development and progression of pancreatic cancer. Pancreatic cancer is one of the deadliest forms of cancer with one of the lowest 5-year survival rates of all cancer types. A defining characteristic of pancreatic cancer is the existence of dense desmoplastic stroma that, when exposed to stimuli such as cytokines, growth factors, and chemokines, generate a tumor-promoting environment. Cancer-associated fibroblasts (CAFs) are activated during the progression of pancreatic cancer and are a crucial component of the tumor microenvironment (TME). CAFs are primarily pro-tumorigenic in their activated state and function as promoters of cancer invasion, proliferation, metastasis, and immune modulation. Aided by many signaling pathways, cytokines, and chemokines in the tumor microenvironment, CAFs can originate from many cell types including resident fibroblasts, mesenchymal stem cells, pancreatic stellate cells, adipocytes, epithelial cells, endothelial cells, and other cell types. CAFs are a highly heterogeneous cell type expressing a variety of surface markers and performing a wide range of tumor promoting and inhibiting functions. Single-cell transcriptomic analyses have revealed a high degree of specialization among CAFs. Some examples of CAF subpopulations include myofibrotic CAFs (myCAFs), which exhibit a matrix-producing contractile phenotype; inflammatory CAFs (iCAF) that are classified by their immunomodulating, secretory phenotype; and antigen-presenting CAFs (apCAFs), which have antigen-presenting capabilities and express Major Histocompatibility Complex II (MHC II). Over the last several years, various attempts have been undertaken to describe the mechanisms of CAF–tumor cell interaction, as well as CAF–immune cell interaction, that contribute to tumor proliferation, invasion, and metastasis. Although our understanding of CAF biology in cancer has steadily increased, the extent of CAFs heterogeneity and their role in the pathobiology of pancreatic cancer remains elusive. In this regard, it becomes increasingly evident that further research on CAFs in pancreatic cancer is necessary. [ABSTRACT FROM AUTHOR]

The dense tumor stroma of pancreatic ductal adenocarcinoma (PDAC) and its secreted immune active molecules provide a barrier for chemotherapy treatment as well as for immune cell infiltration to the tumor core, providing a challenge for immunotherapeutic strategies. Consequently, the investigation of processes underlying the interaction between the tumor stroma, particularly activated pancreatic stellate cells (PSCs), and immune cells may offer new therapeutic approaches for PDAC treatment. In this study, we established a 3D PDAC model cultured under flow, consisting of an endothelial tube, PSCs and PDAC organoids. This was applied to study the role of the tumor microenvironment (TME) on immune cell recruitment and its effect on partly preventing their interaction with pancreatic cancer cells. We observed that stromal cells form a physical barrier, partly shielding the cancer cells from migrating immune cells, as well as a biochemical microenvironment, that seems to attract and influence immune cell distribution. In addition, stromal targeting by Halofuginone led to an increase in immune cell infiltration. We propose that the here developed model setups will support the understanding of the cellular interplay influencing the recruitment and distribution of immune cells, and contribute to the identification of key players in the PDAC immunosuppressive TME as well as support the discovery of new strategies to treat this immune unresponsive tumor. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer-associated fibroblasts (CAFs) represent an important stromal cell population of pancreatic cancer in which multiple CAF subtypes have been identified. CAFs engage in a bidirectional crosstalk with cancer cells, continuously adapting their metabolism to external factors, such as chemotherapy. In this review, we summarize recently identified CAF subtypes in pancreatic cancer and discuss how CAFs shape cancer cell metabolism through several mechanisms, notably metabolite exchange, paracrine signaling, desmoplasia/hypoxia and acidosis. Despite extensive research, the 5-year survival rate of pancreatic cancer (PDAC) patients remains at only 9%. Patients often show poor treatment response, due partly to a highly complex tumor microenvironment (TME). Cancer-associated fibroblast (CAF) heterogeneity is characteristic of the pancreatic TME, where several CAF subpopulations have been identified, such as myofibroblastic CAFs (myCAFs), inflammatory CAFs (iCAFs), and antigen presenting CAFs (apCAFs). In PDAC, cancer cells continuously adapt their metabolism (metabolic switch) to environmental changes in pH, oxygenation, and nutrient availability. Recent advances show that these environmental alterations are all heavily driven by stromal CAFs. CAFs and cancer cells exchange cytokines and metabolites, engaging in a tight bidirectional crosstalk, which promotes tumor aggressiveness and allows constant adaptation to external stress, such as chemotherapy. In this review, we summarize CAF diversity and CAF-mediated metabolic rewiring, in a PDAC-specific context. First, we recapitulate the most recently identified CAF subtypes, focusing on the cell of origin, activation mechanism, species-dependent markers, and functions. Next, we describe in detail the metabolic crosstalk between CAFs and tumor cells. Additionally, we elucidate how CAF-driven paracrine signaling, desmoplasia, and acidosis orchestrate cancer cell metabolism. Finally, we highlight how the CAF/cancer cell crosstalk could pave the way for new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Emerging evidence has revealed the critical role of the tumor microenvironment (TME) in tumor progression, angiogenesis, metastasis, and immunosuppression. Oncolytic viruses (OVs), a versatile therapeutic agent that targets both cancer cells and the TME, have emerged as a promising candidate for antitumor therapy. Strategies of manipulating OVs against the TME include normalization of the tumor vasculature, decomposition of the tumor stroma, and reversion of the immunosuppressive microenvironment. In pancreatic cancer, desmoplastic stroma comprises up to 80% of the tumor mass, accompanied by hypovascularity and profound immunosuppression, conferring a particularly important role to TME-targeted oncolytic virotherapy. Mechanisms and supporting evidence of OVs reversing the tumor-privileged TME and applications of TME-targeted OVs for pancreatic cancer are summarized in this review. [ABSTRACT FROM AUTHOR]

Pancreatic fibrosis (PF) is an essential component of the pathobiology of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC). Activated pancreatic myofibroblasts (PMFs) are crucial for the deposition of the extracellular matrix, and fibrotic reaction in response to sustained signaling. Consequently, understanding of the molecular mechanisms of PMF activation is not only critical for understanding CP and PDAC biology but is also a fertile area of research for the development of novel therapeutic strategies for pancreatic pathologies. This review analyzes the key signaling events that drive PMF activation including, initiating signals from transforming growth factor-β1, platelet derived growth factor, as well as other microenvironmental cues, like hypoxia and extracellular matrix rigidity. Further, we discussed the intracellular signal events contributing to PMF activation, and crosstalk with different components of tumor microenvironment. Additionally, association of epidemiologically established risk factors for CP and PDAC, like alcohol intake, tobacco exposure, and metabolic factors with PMF activation, is discussed to comprehend the role of lifestyle factors on pancreatic pathologies. Overall, this analysis provides insight into the biology of PMF activation and highlights salient features of this process, which offer promising therapeutic targets. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma is a devastating disease with poor outcome, generally characterized by an excessive stroma component. The purpose of this study was to develop a simple and reproducible in vitro 3D-assay employing the main constituents of pancreatic ductal adenocarcinoma, namely pancreatic stellate and cancer cells.Method: A spheroid assay, directly co-culturing human pancreatic stellate cells with human pancreatic tumour cells in 3D was established and characterized by electron microscopy, immunohistochemistry and real-time RT-PCR. In order to facilitate the cell type-specific crosstalk analysis by real-time RT-PCR, we developed a novel in vitro 3D co-culture model, where the participating cell types were from different species, human and mouse, respectively. Using species-specific PCR primers, we were able to investigate the crosstalk between stromal and cancer cells without previous cell separation and sorting.Results: We found clear evidence for mutual influence, such as increased proliferation and a shift towards a more mesenchymal phenotype in cancer cells and an activation of pancreatic stellate cells towards the myofibroblast phenotype. Using a heterospecies approach, which we coined virtual sorting, confirmed the findings we made initially in the human-human spheroids.Conclusions: We developed and characterized different easy to set up 3D models to investigate the crosstalk between cancer and stroma cells for pancreatic cancer. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic cancer is a malignant tumor of the digestive system with poor prognosis and high mortality, and the treatment of pancreatic cancer still remains a major challenge. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce apoptosis selectively in cancer cells while causing virtually no damage to normal cells, which is promising for cancer therapy. However, many primary tumors and cancer cell lines including various human pancreatic cancer cell lines were found to be resistant to TRAIL-induced apoptosis. Therefore, the purpose of the study was to improve antitumor effect of TRAIL on pancreatic cancer.Methods: The 114-121 amino acid coding sequence "VRERGPQR" of wild type TRAIL protein that was selected changed into "RRRRRRRR", and the novel membrane-penetrating peptide-alike mutant protein was named TRAIL-Mu3. The antitumor effect of TRAIL-Mu3 was analyzed both in vitro and in vivo. Western blotting, immunofluorescence and flow cytometry were used to investigate the underlying mechanisms.Results: TRAIL-Mu3 could enhance the antitumor effects on pancreatic cancer cell lines, and the antitumor effect of TRAIL-Mu3 was stronger than gemcitabine in vivo. The immunofluorescence results suggested that TRAIL-Mu3 could remarkably enhance the affinity to pancreatic cancer cells. The Western blot results showed that treatment with TRAIL-Mu3 caused a clear cleavage of caspase-3 and caspase-8. In addition, both the Western blot and flow cytometry suggested a significantly up-expression of DR5 in TRAIL-Mu3 group.Conclusions: Membrane-penetrating peptide-alike mutant-TRAIL-Mu3 induced pancreatic cancer cell death more efficiently than TRAIL, and this effect was supposed to be mediated by the increased affinity to cell membrane, the up-regulation of DR5 and the enhancement of activated caspase. [ABSTRACT FROM AUTHOR]

Purpose: Predicting the biologic behavior of intraductal papillary mucinous neoplasm (IPMN) remains challenging. Current guidelines utilize patient symptoms and imaging characteristics to determine appropriate surgical candidates. However, the majority of resected cysts remain low-risk lesions, many of which may be feasible to have under surveillance. We herein characterize the most promising and up-to-date molecular diagnostics in order to identify optimal components of a molecular signature to distinguish levels of IPMN dysplasia.Methods: A comprehensive systematic review of pertinent literature, including our own experience, was conducted based on the PRISMA guidelines.Results: Molecular diagnostics in IPMN patient tissue, duodenal secretions, cyst fluid, saliva, and serum were evaluated and organized into the following categories: oncogenes, tumor suppressor genes, glycoproteins, markers of the immune response, proteomics, DNA/RNA mutations, and next-generation sequencing/microRNA. Specific targets in each of these categories, and in aggregate, were identified by their ability to both characterize a cyst as an IPMN and determine the level of cyst dysplasia.Conclusions: Combining molecular signatures with clinical and imaging features in this era of next-generation sequencing and advanced computational analysis will enable enhanced sensitivity and specificity of current models to predict the biologic behavior of IPMN. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is one of the most malignant tumors that are difficult to diagnose at its early stage and there is no effective therapy. Recent studies uncovered that many non-protein-coding RNAs including the class of long noncoding RNAs (lncRNAs) are differentially expressed in various types of tumors and they are potent regulators of tumor progression and metastasis. LncRNA can mediate tumor initiation, proliferation, migration and metastasis through modulating epigenetic modification, alternative splicing, transcription, and protein translation. In this review, we discuss the molecular mechanism of lncRNAs in the involvement of tumor growth, survival, epithelial-mesenchymal transition, tumor microenvironment, cancer stem cells and chemoresistance in pancreatic ductal adenocarcinoma (PDAC). [ABSTRACT FROM PUBLISHER]

Background: Cancer microenvironment plays a vital role in cancer development and progression, and cancer-stromal interactions have been recognized as important targets for cancer therapy. However, identifying relevant and druggable cancer-stromal interactions is challenging due to the lack of quantitative methods to analyze whole cancer-stromal interactome. Results: We present CASTIN (CAncer-STromal INteractome analysis), a novel framework for the evaluation of cancer-stromal interactome from RNA-Seq data using cancer xenograft models. For each ligand-receptor interaction which is derived from curated protein-protein interaction database, CASTIN summarizes gene expression profiles of cancer and stroma into three evaluation indices. These indices provide quantitative evaluation and comprehensive visualization of interactome, and thus enable to identify critical cancer-microenvironment interactions, which would be potential drug targets. We applied CASTIN to the dataset of pancreas ductal adenocarcinoma, and successfully characterized the individual cancer in terms of cancer-stromal relationships, and identified both well-known and less-characterized druggable interactions. Conclusions: CASTIN provides comprehensive view of cancer-stromal interactome and is useful to identify critical interactions which may serve as potential drug targets in cancer-microenvironment. CASTIN is available at: http://github.com/tmd-gpat/CASTIN. [ABSTRACT FROM AUTHOR]

In this study, we demonstrated that survivin downregulation with TRAIL expression greatly enhanced the cytotoxic death of pancreatic cancer cells after gemcitabine treatment. Using real-time RT-PCR, we analyzed five survivin shRNAs to identify the best target sequence for suppression of human survivin, with the goal of treating gemcitabine-resistant pancreatic cancer cells. Survivin shRNA 5, corresponding to target 5, showed the greatest reduction in survivin mRNA levels. Furthermore, combined treatment with survivin shRNA-expressing adenovirus with gemcitabine plus TRAIL decreased uncleaved PARP and increased consequent PARP cleavage, which was correlated with the greatest levels of survivin downregulation and cell death. These results indicate that survivin functions as a common mediator of gemcitabine- and TRAIL-induced cell death. Using a nude mouse model implanted with MiaPaCa-2 pancreatic cancer cells, we observed tumor regression induced by an oncolytic adenovirus expressing survivin shRNA and TRAIL plus gemcitabine. Together, our findings provide a strong rationale for treating pancreatic cancer patients with both gemcitabine and oncolytic adenovirus armed with survivin shRNA and TRAIL. [ABSTRACT FROM AUTHOR]

Background: Pancreatic stellate cells (PSCs) play a critical role in pancreatic ductal adenocarcinoma (PDAC). Activated PSCs are the main source of fibrosis in chronic pancreatitis and of desmoplasia in PDAC. The majority of studies on PSC are based on in vitro experiments relying on immortalized cell lines derived from diseased human pancreas or from animal models. These PSCs are usually activated and may not represent the biological context of their tissue of origin. Purpose: (1) To isolate and culture primary human PSC from different disease contexts with minimal impact on their state of activation. (2) To perform a comparative analysis of phenotypes of PSC derived from different contexts. Methods: PSCs were isolated from normal pancreas, chronic pancreatitis, and PDAC using a hybrid method of digestion and outgrowth. To minimize activation by serum compounds, cells were cultured in a low-serum environment (2.5 % fetal bovine serum (FBS)). Expression patterns of commonly used markers for PSC phenotype and activity were compared between primary PSC lines derived from different contexts and correlated to expression in their original tissues. Results: Isolation was successful from 14 of 17 tissues (82 %). Isolated PSC displayed stable viability and phenotype in low-serum environment. Expression profiles of isolated PSC and matched original tissues were closely correlated. PDAC-derived PSC tended to have a higher status of activation if compared to PSC derived from non-cancerous tissues. Conclusions: Primary human PSCs isolated from different contexts and cultured in a low-serum environment maintain a phenotype that reflects the stromal activity present in their tissue of origin. [ABSTRACT FROM AUTHOR]

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Oncolytic viruses have demonstrated in pre-clinical and clinical studies safety and a unique pleiotropic activity profile of tumor destruction. Yet, their delivery suffers from virus inactivation by blood components and sequestration to healthy tissues. Therefore, mesenchymal stromal cells (MSCs) have been applied as carrier cells for shielded virus delivery to tumors after ex vivo infection with oncolytic viruses. However, infection and particle production by MSCs have remained unsatisfying. Here, we report engineered oncolytic adenoviruses (OAds) for improved virus production and delivery by MSCs. OAds are uniquely amenable to molecular engineering, which has facilitated improved tumor cell destruction. But for MSC-mediated regimens, OAd engineering needs to achieve efficient infection and replication in both MSCs and tumor cells. We show that an Ad5/3 chimeric OAd capsid, containing the adenovirus serotype 3 cell-binding domain, strongly increases the entry into human bone marrow-derived MSCs and into established and primary pancreatic cancer cells. Further, we reveal that OAd with engineered post-entry functions-by deletion of the anti-apoptotic viral gene E1B19K or expression of the death ligand TRAIL-markedly increased virus titers released from MSCs, while MSC migration was not hampered. Finally, these virus modifications, or viral expression of FCU1 for local 5-FC prodrug activation, improved tumor cell killing implementing complementary cytotoxicity profiles in a panel of pancreatic cancer cell cultures. Together, our study establishes post-entry modification of OAd replication for improving virus delivery by carrier cells and suggests a panel of optimized OAds for future clinical development in personalized treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus is linked to pancreatic cancer. We hypothesized a role for pancreatic stellate cells (PSC) in the hyperglycemia induced deterioration of pancreatic cancer and therefore studied two human cell lines (RLT-PSC, T3M4) in hyperglycemic environment. Methodology/Principal Findings: The effect of chronic hyperglycemia (CHG) on PSCs was studied using mRNA expression array with real-time PCR validation and bioinformatic pathway analysis, and confirmatory protein studies. The stress fiber formation (IC: αSMA) indicated that PSCs tend to transdifferentiate to a myofibroblast-like state after exposure to CHG. The phosphorylation of p38 and ERK1/2 was increased with a consecutive upregulation of CDC25, SP1, cFOS and p21, and with downregulation of PPARγ after PSCs were exposed to chronic hyperglycemia. CXCL12 levels increased significantly in PSC supernatant after CHG exposure independently from TGF-β1 treatment (3.09-fold with a 2.73-fold without TGF-β1, p<0.05). The upregualtion of the SP1 transcription factor in PSCs after CHG exposure may be implicated in the increased CXCL12 and IGFBP2 production. In cancer cells, hyperglycemia induced an increased expression of CXCR4, a CXCL12 receptor that was also induced by PSC’s conditioned medium. The receptor-ligand interaction increased the phosphorylation of ERK1/2 and p38 resulting in activation of MAP kinase pathway, one of the most powerful stimuli for cell proliferation. Certainly, conditioned medium of PSC increased pancreatic cancer cell proliferation and this effect could be partially inhibited by a CXCR4 inhibitor. As the PSC conditioned medium (normal glucose concentration) increased the ERK1/2 and p38 phosphorylation, we concluded that PSCs produce other factor(s) that influence(s) pancreatic cancer behaviour. Conclusions: Hyperglycemia induces increased CXCL12 production by the PSCs, and its receptor, CXCR4 on cancer cells. The ligand-receptor interaction activates MAP kinase signaling that causes increased cancer cell proliferation and migration. [ABSTRACT FROM AUTHOR]

Members of the Hedgehog (Hh) family of morphogens play crucial roles in development but are also involved in the progression of certain types of cancer. Despite being synthesized as hydrophobic dually lipid-modified molecules, and thus being strongly membrane-associated, Hh ligands are able to spread through tissues and act on target cells several cell diameters away. Various mechanisms that mediate Hh release have been discussed in recent years; however, little is known about dispersion of this ligand from cancer cells. Using co-culture models in conjunction with a newly developed reporter system, we were able to show that different members of the ADAM family of metalloproteinases strongly contribute to the release of endogenous bioactive Hh from pancreatic cancer cells, but that this solubilization decreases the potency of cancer cells to signal to adjacent stromal cells in direct co-culture models. These findings imply that under certain conditions, cancer-cell-tethered Hh molecules are the more potent signaling activators and that retaining Hh on the surface of cancer cells can unexpectedly increase the effective signaling range of this ligand, depending on tissue context. [ABSTRACT FROM AUTHOR]

Previous studies have suggested that the 8-oxoguanine DNA glycosylase gene ( OGG1) has potentially influenced the risk of pancreatic cancer. The objective of this study was to assess the association between single nucleotide polymorphisms (SNPs) of OGG1 gene and risk of pancreatic cancer. A case-control study has been conducted in 370 pancreatic cancer patients and 395 healthy controls. Genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. The association analysis was evaluated by the unconditional logistic regression test. Our data suggested that the distributions of alleles and genotypes were statistically different between pancreatic cancer patients and healthy controls. The c.307G>C SNP was associated with the decreased risk of pancreatic cancer (C vs. G: OR 0.73, 95 % CI 0.59-0.91, P = 0.006). As for c.828A>G SNP, the significantly decreased risk of pancreatic cancer was detected (G vs. A: OR 0.74, 95 % CI 0.59-0.92, P = 0.006). The allele C of c.307G>C and allele G of c.828A>G SNPs might be associated with a protection from pancreatic cancer. Findings from this study indicate that OGG1 SNPs are associated with pancreatic cancer risk in Chinese Han population and could be useful molecular biomarkers for assessing the risk of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Patients with chronic pancreatitis with local inflammation have high risk for pancreatic cancer. The aim of this study was to examine the role of the inflammatory cells in the invasion of pancreatic cancer cells, focusing on the involvement of a disintegrin and metalloproteinase 8 (ADAM8) and matrix metalloproteinase 9 (MMP9) proteins. ADAM8 expression is associated with worse survival of pancreatic cancer patients. Monocytes from healthy donors were differentiated into macrophages. Pancreatic adenocarcinoma cells were cultured either alone or with differentiated macrophages. The cancer cell migration rate in Matrigel was measured by imaging fluorescently stained cells for 24 h. After invasion, cells were sorted into CD14 positive/negative macrophages and cancer cells with magnetic separation. The expression of ADAM8 and MMP9 was measured by the real-time PCR. Protein-level expression of ADAM8 and MMP9 was analyzed by Western blotting. In two series, siRNA technique was used to reduce either ADAM8 or MMP9 expression in the cancer cells. The coculture with macrophages increased cancer cell migration rate in Matrigel, and increased ADAM8 and MMP9 mRNA expression and protein level in the cancer cells. Reduction of ADAM8 expression with siRNA in the cancer cells decreased macrophage-induced migration rate of the cancer cells from 11.7 ± 0.3 μm/h to 9.0 ± 0.2 μm/h ( p < 0.01), and reduction of MMP9 expression decreased the migration rate to 10.1 ± 0.2 μm/h ( p < 0.01). Anti-inflammatory macrophages increase pancreatic cancer cell migration rate in basement membrane matrix by inducing ADAM8 and MMP9 expression in cancer cells, thereby possibly enhancing the invasiveness of cancer. [ABSTRACT FROM AUTHOR]

Background PAM4, an antibody that has high specificity for pancreatic ductal adenocarcinoma (PDAC), compared to normal pancreas, benign lesions of the pancreas, and cancers originating from other tissues, is being investigated as a biomarker for early detection, as well as antibody-targeted imaging and therapy. Therefore, the identity of the antigen bound by this monoclonal antibody (MAb) can provide information leading to improved use of the antibody. Prior results suggested the antigen is a mucin-type glycoprotein rich in cysteine disulfide bridges that provide stable conformation for the PAM4-epitope. Methods Indirect and sandwich enzyme immunoassays (EIA) were performed to compare and contrast the reactivity of PAM4 with several anti-mucin antibodies having known reactivity to specific mucin species (e.g., MUC1, MUC4, MUC5AC, etc.). Studies designed to block reactivity of PAM4 with its specific antigen also were performed. Results We demonstrate that MAbs 2-11 M1 and 45 M1, each reactive with MUC5AC, are able to provide signal in a heterologous sandwich immunoassay where PAM4 is the capture antibody. Further, we identify MAbs 21 M1, 62 M1, and 463 M1, each reactive with MUC5AC, as inhibiting the reaction of PAM4 with its specific epitope. MAbs directed to MUC1, MUC3, MUC4, MUC16 and CEACAM6 are not reactive with PAM4-captured antigen, nor are they able to block the reaction of PAM4 with its antigen. Conclusions These data implicate MUC5AC as a specific mucin species to which PAM4 is reactive. Furthermore, this realization may allow for the improvement of the current PAM4 serumbased immunoassay for detection of early-stage PDAC by the application of anti-MUC5AC MAbs as probes in this sandwich EIA. [ABSTRACT FROM AUTHOR]

Despite evidence that long-term smoking is the leading risk factor for pancreatic malignancies, the underlying mechanism(s) for cigarette-smoke (CS)-induced pancreatic cancer (PC) pathogenesis has not been well established. Our previous studies revealed an aberrant expression of the MUC4 mucin in PC as compared with the normal pancreas, and its association with cancer progression and metastasis. Interestingly, here we explore a potential link between MUC4 expression and smoking-mediated PC pathogenesis and report that both cigarette smoke extract and nicotine, which is the major component of CS, significantly upregulates MUC4 in PC cells. This nicotine-mediated MUC4 overexpression was via the α7 subunit of nicotinic acetylcholine receptor (nAChR) stimulation and subsequent activation of the JAK2/STAT3 downstream signaling cascade in cooperation with the MEK/ERK1/2 pathway; this effect was blocked by the α7nAChR antagonists, α-bungarotoxin and mecamylamine, and by specific siRNA-mediated STAT3 inhibition. In addition, we demonstrated that nicotine-mediated MUC4 upregulation promotes the PC cell migration through the activation of the downstream effectors, such as HER2, c-Src and FAK; this effect was attenuated by shRNA-mediated MUC4 abrogation, further implying that these nicotine-mediated pathological effects on PC cells are MUC4 dependent. Furthermore, the in vivo studies showed a marked increase in the mean pancreatic tumor weight (low dose (100 mg/m3 total suspended particulate (TSP)), P=0.014; high dose (247 mg/m3 TSP), P=0.02) and significant tumor metastasis to various distant organs in the CS-exposed mice, orthotopically implanted with luciferase-transfected PC cells, as compared with the sham controls. Moreover, the CS-exposed mice had elevated levels of serum cotinine (low dose, 155.88±35.96 ng/ml; high dose, 216.25±29.95 ng/ml) and increased MUC4, α7nAChR and pSTAT3 expression in the pancreatic tumor tissues. Altogether, our findings revealed for the first time that CS upregulates the MUC4 mucin in PC via the α7nAChR/JAK2/STAT3 downstream signaling cascade, thereby promoting metastasis of PC. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) have attracted great interest in cancer therapy owing to their tumor-oriented homing capacity and the feasibility of autologous transplantation. Currently, pancreatic cancer patients face a very poor prognosis, primarily due to the lack of therapeutic strategies with an effective degree of specificity. Anticancer gene-engineered MSCs specifically target tumor sites and can produce anticancer agents locally and constantly. This study was performed to characterize pancreas-derived MSCs and investigate the effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-engineered MSCs on pancreatic cancer cells under different culture conditions. Pancreas-derived MSCs exhibited positive expression on CD44, CD73, CD95, CD105, negative on CD34 and differentiated into adipogenic and osteogenic cells. TRAIL expression was assessed by both enzyme-linked immunosorbent assay and western blot analysis. Different patterns of TRAIL receptor expression were observed on the pancreatic cancer cell lines, including PANC1, HP62, ASPC1, TRM6 and BXPC3. Cell viability was assessed using a real-time monitoring system. Pancreatic cancer cell death was proportionally related to conditioned media from MSCnsTRAIL and MSCstTRAIL. The results suggest that MSCs exhibit intrinsic inhibition of pancreatic cancer cells and that this effect can be potentiated by TRAIL-transfection on death receptor-bearing cell types. [ABSTRACT FROM AUTHOR]

While the morphology and function of cells of the exocrine and endocrine pancreas have been studied over several centuries, one important cell type in the gland, the pancreatic stellate cell (PSC), had remained undiscovered until as recently as 20 years ago. Even after its first description in 1982, it was to be another 16 years before its biology could begin to be studied, because it was only in 1998 that methods were developed to isolate and culture PSCs from rodent and human pancreas. PSCs are now known to play a critical role in pancreatic fibrosis, a consistent histological feature of two major diseases of the pancreas-chronic pancreatitis and pancreatic cancer. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM) proteins. Recent studies have also implied other functions for PSCs as progenitor cells, immune cells or intermediaries in exocrine pancreatic secretion in humans. During pancreatic injury, PSCs transform from their quiescent phase into an activated, myofibroblast-like phenotype that secretes excessive amounts of ECM proteins leading to the fibrosis of chronic pancreatitis and pancreatic cancer. An ever increasing number of factors that stimulate and/or inhibit PSC activation via paracrine and autocrine pathways are being identified and characterized. It is also now established that PSCs interact closely with pancreatic cancer cells to facilitate cancer progression. Based on these findings, several therapeutic strategies have been examined in experimental models of chronic pancreatitis as well as pancreatic cancer, in a bid to inhibit/retard PSC activation and thereby alleviate chronic pancreatitis or reduce tumor growth in pancreatic cancer. The challenge that remains is to translate these pre-clinical developments into clinically applicable treatments for patients with chronic pancreatitis and pancreatic cancer. [ABSTRACT FROM AUTHOR]

With the continued failures of both early diagnosis and treatment options for pancreatic cancer, it is now time to comprehensively evaluate the role of the immune system on the development and progression of pancreatic cancer. It is important to develop strategies that harness the molecules and cells of the immune system to treat this disease. This review will focus primarily on the role of immune cells in the development and progression of pancreatic ductal adenocarcinoma and to evaluate what is known about the interaction of immune cells with the tumor microenvironment and their role in tumor growth and metastasis. We will conclude with a brief discussion of therapy for pancreatic cancer and the potential role for immunotherapy. We hypothesize that the role of the immune system in tumor development and progression is tissue specific. Our hope is that better understanding of this process will lead to better treatments for this devastating disease. [ABSTRACT FROM AUTHOR]

One of the characteristic features of the majority of pancreatic ductal adenocarcinomas is an abundant desmoplastic/stromal reaction. Until recently, this stroma had received little attention from researchers studying the pathogenesis of pancreatic cancer, with most of the research focus resting on the biology of tumor cells themselves. However, evidence is now accumulating that the stroma plays a critical role in pancreatic cancer progression. The cells responsible for producing the stromal reaction in pancreatic cancer are activated pancreatic stellate cells (PSCs, the key effector cells in pancreatic fibrogenesis). In vitro and in vivo studies have convincingly demonstrated a close bi-directional interaction between PSCs and pancreatic cancer cells, which facilitates local tumor growth as well as distant metastasis. PSCs also interact closely with endothelial cells to stimulate angiogenesis and are possibly involved in the known resistance of pancreatic cancer to chemotherapy and radiation. Most interestingly, it has recently been shown that PSCs from the primary tumor can travel to distant metastatic sites where they likely facilitate the seeding, survival, and proliferation of cancer cells. Thus, it is now recognized that the stroma is an important alternative therapeutic target in this disease and concerted pre-clinical research is underway to develop strategies to modulate/deplete the stromal reaction to inhibit cancer progression. The challenge is to translate these developments into clinically applicable treatments for patients. [ABSTRACT FROM AUTHOR]

MUC16 (CA125) belongs to a family of high-molecular weight O-glycosylated proteins known as mucins. While MUC16 is well known as a biomarker in ovarian cancer, its expression pattern in pancreatic cancer (PC), the fourth leading cause of cancer related deaths in the United States, remains unknown. The aim of our study was to analyze the expression of MUC16 during the initiation, progression and metastasis of PC for possible implication in PC diagnosis, prognosis and therapy. In this study, a microarray containing tissues from healthy and PC patients was used to investigate the differential protein expression of MUC16 in PC. MUC16 mRNA levels were also measured by RT-PCR in the normal human pancreatic, pancreatitis, and PC tissues. To investigate its expression pattern during PC metastasis, tissue samples from the primary pancreatic tumor and metastases (from the same patient) in the lymph nodes, liver, lung and omentum from Stage IV PC patients were analyzed. To determine its association in the initiation of PC, tissues from PC patients containing preneoplastic lesions of varying grades were stained for MUC16. Finally, MUC16 expression was analyzed in 18 human PC cell lines. MUC16 is not expressed in the normal pancreatic ducts and is strongly upregulated in PC and detected in pancreatitis tissue. It is first detected in the high-grade pre-neoplastic lesions preceding invasive adenocarcinoma, suggesting that its upregulation is a late event during the initiation of this disease. MUC16 expression appears to be stronger in metastatic lesions when compared to the primary tumor, suggesting a role in PC metastasis. We have also identified PC cell lines that express MUC16, which can be used in future studies to elucidate its functional role in PC. Altogether, our results reveal that MUC16 expression is significantly increased in PC and could play a potential role in the progression of this disease. [ABSTRACT FROM AUTHOR]

IκB kinase (IKKε) is a serine/threonine protein kinase that belongs to the IKK kinase family. Recent studies have shown that IKKε functions as a breast and ovarian cancer oncogene. We demonstrated frequent overexpression of IKKε in pancreatic ductal adenocarcinoma (PDA). We immunohistochemically evaluated 78 PDAs using the avidin-biotin-peroxidase method and the anti-IKKε rabbit polyclonal antibody. Elevated IKKε reactivity (immunohistochemical score, 4-9) was observed in 64% of PDAs (50/78), but in 0.0% of nonneoplastic pancreatic ductal epithelium (0/113; P < .001). Kaplan-Meier analysis of overall survival revealed that patients with high IKKε-immunohistochemical scores (4-9) had significantly shorter survival than did patients with low IKKε immunohistochemical scores (0-3; P = .023; log-rank test) independent of tumor stage or grade. These data indicate that deregulation of IKKε is a common event in PDA and might have an important role in the pathogenesis of this deadly disease. In addition, IKKε could serve as a prognostic marker and potential therapeutic target for PDA intervention. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is associated with a pronounced collagen-rich fibrosis known as desmoplastic reaction; however, the role of fibrosis in PDAC is poorly understood. In this report we show that collagen can regulate the tumor suppressive let-7 family of microRNAs in pancreatic cancer cells. PDAC cells growing in 3D collagen gels repress mature let-7 without affecting the precursor form of let-7 in part through increased expression of membrane type 1-matrix metalloproteinase (MT1-MMP, MMP-14) and ERK1/2 activation. PDAC cells in collagen also demonstrate increased TGF-β1 signaling, and blocking TGF-β1 signaling attenuated collagen-induced MT1-MMP expression, ERK1/2 activation and repression of let-7 levels. Although MT1-MMP overexpression was not sufficient to inhibit let-7 on 2D tissue culture plastic, overexpression of MT1-MMP in PDAC cells embedded in 3D collagen gels or grown in vivo repressed let-7 levels. Importantly, MT1-MMP expression significantly correlated with decreased levels of let-7 in human PDAC tumor specimens. Overall, our study emphasizes the interplay between the key proteinase MT1-MMP and its substrate type I collagen in modulating microRNA expression, and identifies an additional mechanism by which fibrosis may contribute to PDAC progression. [ABSTRACT FROM AUTHOR]

BACKGROUND: Evasion of apoptosis is a hallmark of pancreatic cancer. However, the underlying mechanisms are still only partly understood and may involve antiapoptotic proteins such as c-FLIP. Here, the role of c-FLIP in the regulation of death receptor-mediated apoptosis in pancreatic cancer was investigated. METHODS: Expression of c-FLIPLand c-FLIPSwas analysed in primary pancreatic carcinoma samples, pancreatic carcinoma cell lines and primary tumour cells together with its function as a regulator of death receptor-induced apoptosis by knockdown and overexpression studies and through modulation by chemotherapeutics. RESULTS: c-FLIP is expressed in pancreatic intraepithelial neoplasm (PanIN) lesions and in pancreatic ductal adenocarcinomas, whereas normal pancreatic ducts were consistently negative for c-FLIP. Simultaneous downregulation of c-FLIPLand c-FLIPSas well as individual knockdown of either isoform by RNA interference significantly enhances TRAIL (tumour necrosis factor-related apoptosis-inducing ligand)- and CD95-induced caspase activation and caspase-dependent apoptosis. Also, pretreatment with chemotherapeutic drugs—that is, 5-fluorouracil (5-FU), cisplatin or gemcitabine—downregulates c-FLIP and renders cells sensitive to death receptor-triggered apoptosis. Similarly, primary cultured pancreatic cancer cells are primed for TRAIL-induced apoptosis by pre-exposure to 5-FU or cisplatin. Mechanistic studies revealed that 5-FU-mediated suppression of c-FLIP results in increased TRAIL-induced recruitment and activation of caspase-8 at the death-inducing signalling complex (DISC), leading to caspase-3 activation and caspase-dependent cell death. Overexpression of c-FLIPLrescues cells from 5-FU- or cisplatin-mediated sensitisation for TRAIL-induced apoptosis, indicating that c-FLIP suppression is a key event in this chemotherapy-mediated sensitisation to TRAIL. Further, concomitant neutralisation of c-FLIP and XIAP acts in concert to potentiate TRAIL-induced apoptosis. CONCLUSIONS: Both the long and the short isoform of the antiapoptotic protein c-FLIP are critical regulators of death receptor-induced apoptosis in pancreatic carcinoma cells and are suppressed by chemotherapeutics. Targeting either c-FLIPLor c-FLIPSis sufficient to promote death receptor-induced apoptosis in pancreatic carcinoma cells. These findings have important implications for the design of TRAIL-based combination protocols in pancreatic cancer. [ABSTRACT FROM AUTHOR]

Haugk B (2010) Histopathology 57, 503-514 Pancreatic intraepithelial neoplasia - can we detect early pancreatic cancer? Pancreatic cancer is one of the most lethal cancers, with an incidence equalling mortality. Pancreatic cancer is a heterogeneous group in which pancreatic ductal adenocarcinoma (PDAC) is the most common. It is now established that PDAC develops through stepwise progression from precursor lesions. Detection and treatment of these precursor lesions would allow curative treatment. Three precursor lesions for PDAC have been identified. Two of these - mucinous cystic neoplasms (MCNs) and intraductal papillary mucinous neoplasms (IPMNs) - are rare, radiologically detectable, cystic precursor lesions which can be cured if treated at the preinvasive stage. The third and most common precursor lesion has recently been defined as pancreatic intraepithelial neoplasia (PanIN). PanINs are microscopic lesions with no clinical correlate. They display a spectrum of cyto-architectural changes (PanIN-1, PanIN-2 and PanIN-3) mirrored in an increasing accumulation of molecular genetic changes, with PanIN-3 sharing many of the alterations with PDAC. Great advances in the understanding of pancreatic carcinogenesis have opened avenues for diagnosis and chemoprevention. However, access to the pancreas is limited, molecular tests are at the early stages and too little is known about the natural history of early PanINs to justify resection. Currently, screening focuses upon high-risk individuals only. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer death. Changes in apoptosis signaling in pancreatic cancer result in chemotherapy resistance and aggressive growth and metastasizing. The aim of this study was to characterize the apoptosis pathway in pancreatic cancer computationally by evaluation of experimental data from high-throughput technologies and public data bases. Therefore, gene expression analysis of microdissected pancreatic tumor tissue was implemented in a model of the apoptosis pathway obtained by computational protein interaction prediction. Methodology/Principal Findings: Apoptosis pathway related genes were assembled from electronic databases. To assess expression of these genes we constructed a virtual subarray from a whole genome analysis from microdissected native tumor tissue. To obtain a model of the apoptosis pathway, interactions of members of the apoptosis pathway were analysed using public databases and computational prediction of protein interactions. Gene expression data were implemented in the apoptosis pathway model. 19 genes were found differentially expressed and 12 genes had an already known pathophysiological role in PDAC, such as Survivin/BIRC5, BNIP3 and TNF-R1. Furthermore we validated differential expression of IL1R2 and Livin/BIRC7 by RT-PCR and immunohistochemistry. Implementation of the gene expression data in the apoptosis pathway map suggested two higher level defects of the pathway at the level of cell death receptors and within the intrinsic signaling cascade consistent with references on apoptosis in PDAC. Protein interaction prediction further showed possible new interactions between the single pathway members, which demonstrate the complexity of the apoptosis pathway. Conclusions/Significance: Our data shows that by computational evaluation of public accessible data an acceptable virtual image of the apoptosis pathway might be given. By this approach we could identify two higher level defects of the apoptosis pathway in PDAC. We could further for the first time identify IL1R2 as possible candidate gene in PDAC. [ABSTRACT FROM AUTHOR]

Background: Pancreatic cancer is still associated with devastating prognosis. Real progress in treatment options has still not been achieved. Therefore new models are urgently needed to investigate this deadly disease. As a part of this process we have established and characterized a new human pancreatic cancer cell line. Methods: The newly established pancreatic cancer cell line PaCa 5061 was characterized for its morphology, growth rate, chromosomal analysis and mutational analysis of the K-ras, EGFR and p53 genes. Gene-amplification and RNA expression profiles were obtained using an Affymetrix microarray, and overexpression was validated by IHC analysis. Tumorigenicity and spontaneous metastasis formation of PaCa 5061 cells were analyzed in pfp-/-/rag2-/- mice. Sensitivity towards chemotherapy was analysed by MTT assay. Results: PaCa 5061 cells grew as an adhering monolayer with a doubling time ranging from 30 to 48 hours. M-FISH analyses showed a hypertriploid complex karyotype with multiple numerical and unbalanced structural aberrations. Numerous genes were overexpressed, some of which have previously been implicated in pancreatic adenocarcinoma (GATA6, IGFBP3, IGFBP6), while others were detected for the first time (MEMO1, RIOK3). Specifically highly overexpressed genes (fold change > 10) were identified as EGFR, MUC4, CEACAM1, CEACAM5 and CEACAM6. Subcutaneous transplantation of PaCa 5061 into pfp-/-/rag2-/- mice resulted in formation of primary tumors and spontaneous lung metastasis. Conclusion: The established PaCa 5061 cell line and its injection into pfp-/-/rag2-/- mice can be used as a new model for studying various aspects of the biology of human pancreatic cancer and potential treatment approaches for the disease. [ABSTRACT FROM AUTHOR]

Background: A major obstacle to the successful management of pancreatic cancer is to acquire resistance to the existing chemotherapeutic agents. Resistance to gemcitabine, the standard first-line chemotherapeutic agent for advanced and metastatic pancreatic cancer, is mainly attributed to an altered apoptotic threshold in the pancreatic cancer. The MUC4 transmembrane glycoprotein is aberrantly overexpressed in the pancreatic cancer and recently, has been shown to increase pancreatic tumour cell growth by the inhibition of apoptosis.Methods: Effect of MUC4 on pancreatic cancer cells resistance to gemcitabine was studied in MUC4-expressing and MUC4-knocked down pancreatic cancer cell lines after treatment with gemcitabine by Annexin-V staining, DNA fragmentation assay, assessment of mitochondrial cytochrome c release, immunoblotting and co-immunoprecipitation techniques.Results: Annexin-V staining and DNA fragmentation experiment demonstrated that MUC4 protects CD18/HPAF pancreatic cancer cells from gemcitabine-induced apoptosis. In concert with these results, MUC4 also attenuated mitochondrial cytochrome c release and the activation of caspase-9. Further, our results showed that MUC4 exerts anti-apoptotic function through HER2/extracellular signal-regulated kinase-dependent phosphorylation and inactivation of the pro-apoptotic protein Bad.Conclusion: Our results elucidate the function of MUC4 in imparting resistance to pancreatic cancer cells against gemcitabine through the activation of anti-apoptotic pathways and, thereby, promoting cell survival. [ABSTRACT FROM AUTHOR]

Background: ALCAM (activated leucocyte cell adhesion molecule, synonym CD166) is a cell adhesion molecule, which belongs to the Ig superfamily. Disruption of the ALCAM-mediated adhesiveness by proteolytic sheddases such as ADAM17 has been suggested to have a relevant impact on tumour invasion. Although the expression of ALCAM is a valuable prognostic and predictive marker in several types of epithelial tumours, its role as a prognostic marker in pancreatic cancer has not yet been reported.Methods: In this study, paraffin-embedded samples of 97 patients with pancreatic cancer undergoing potentially curative resection were immunostained against ALCAM, ADAM17 and CK19. Expression of ALCAM and ADAM17 was semiquantitatively evaluated and correlated to clinical and histopathological parameters.Results: We could show that in normal pancreatic tissue, ALCAM is predominantly expressed at the cellular membrane, whereas in pancreatic tumour cells, it is mainly localised in the cytoplasm. In addition, univariate and multivariate analyses show that increased expression of ALCAM is an adverse prognostic factor for recurrence-free and overall survival. Overexpression of ADAM17 in pancreatic cancer, however, failed to be a significant prognostic marker and was not coexpressed with ALCAM.Conclusions: Our findings support the hypothesis that the disruption of ALCAM-mediated adhesiveness is a relevant step in pancreatic cancer progression. Moreover, ALCAM overexpression is a relevant independent prognostic marker for poor survival and early tumour relapse in pancreatic cancer. [ABSTRACT FROM AUTHOR]

The prognosis of pancreatic cancer remains poor, mainly because of its aggressive biological behaviour and late clinical diagnosis, which precludes the application of appropriate curative therapies. Therefore, one of the major goals in clinical pancreatology is to find molecular markers, specific and sensitive enough to make an early and correct diagnosis of pancreatic cancer, before it has disseminated and become untreatable. This overview article explores the potential utility of current molecular markers for the diagnosis of pancreatic cancer. There is a wide array of serum-based and tissue-based markers for pancreatic cancer. Serum-based molecular markers include CA 19-9, CA 125, M2-PK and secreted proteins. A tissue can be used to test genetic mutations such as K- ras, inactivation of tumour suppressor genes (e.g. p16, p53), mucins, telomerase activity, growth factors, DNA methylation, and global gene expression of cDNA microarrays, mitochondrial mutations and proteomics. None of these markers is currently useful for the detection of early pancreatic cancer. In clinical practice, the most commonly accepted use of CA 19-9 is to assess the prognosis and monitor the response to therapy. Many molecular markers have been proposed for the early diagnosis of PC, but most are not ready to be included as part of the routine diagnostic algorithm because they still lack sensitivity, specificity or reproducibility. CA 19-9 remains the most useful molecular marker for the diagnosis and follow-up of clinically and radiological evident pancreatic cancer. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is a highly lethal malignancy with a dismal 5-year survival of less than 5%. The scarcity of early biomarkers has considerably hindered our ability to launch preventive measures for this malignancy in a timely manner. Neutrophil gelatinase-associated lipocalin (NGAL), a 24-kDa glycoprotein, was reported to be upregulated nearly 27-fold in pancreatic cancer cells compared to normal ductal cells in a microarray analysis. Given the need for biomarkers in the early diagnosis of pancreatic cancer, we investigated the expression of NGAL in tissues with the objective of examining if NGAL immunostaining could be used to identify foci of pancreatic intraepithelial neoplasia, premalignant lesions preceding invasive cancer. To examine a possible correlation between NGAL expression and the degree of differentiation, we also analysed NGAL levels in pancreatic cancer cell lines with varying grades of differentiation. Although NGAL expression was strongly upregulated in pancreatic cancer, and moderately in pancreatitis, only a weak expression could be detected in the healthy pancreas. The average composite score for adenocarcinoma (4.26±2.44) was significantly higher than that for the normal pancreas (1.0) or pancreatitis (1.0) (P<0.0001). Further, although both well- and moderately differentiated pancreatic cancer were positive for NGAL, poorly differentiated adenocarcinoma was uniformly negative. Importantly, NGAL expression was detected as early as the PanIN-1 stage, suggesting that it could be a marker of the earliest premalignant changes in the pancreas. Further, we examined NGAL levels in serum samples. Serum NGAL levels were above the cutoff for healthy individuals in 94% of pancreatic cancer and 62.5% each of acute and chronic pancreatitis samples. However, the difference between NGAL levels in pancreatitis and pancreatic cancer was not significant. A ROC curve analysis revealed that ELISA for NGAL is fairly accurate in distinguishing pancreatic cancer from non-cancer cases (area under curve=0.75). In conclusion, NGAL is highly expressed in early dysplastic lesions in the pancreas, suggesting a possible role as an early diagnostic marker for pancreatic cancer. Further, serum NGAL measurement could be investigated as a possible biomarker in pancreatitis and pancreatic adenocarcinoma.British Journal of Cancer (2008) 98, 1540–1547; doi:10.1038/sj.bjc.6604329 www.bjcancer.com Published online 8 April 2008 [ABSTRACT FROM AUTHOR]

MUC4 is a transmembrane mucin, which is aberrantly expressed in pancreatic adenocarcinoma with no detectable expression in the normal pancreas. Here, we present a novel mechanism of IFN-γ-induced expression of MUC4 in pancreatic cancer cells. Our studies highlight the upregulation of STAT-1 as a basis for MUC4 induction and demonstrate that its activation and upregulation by IFN-γ are two distinct, albeit temporally integrated, signalling events that drive the selective induction of IRF-1 and MUC4, respectively, within a single cell system. The profile of interferon regulatory factor (IRF)-1 gene induction by IFN-γ is consistent with its rapid transactivation by phospho-Y701-STAT-1. In contrast, the induction of the MUC4 mucin gene expression is relatively delayed, and occurs only in response to an increase in STAT-1 expression. A progressive binding of STAT-1 to various γ-interferon-activated sequences (GAS) in the MUC4 promoter is observed in chromatin immunoprecipitation assay, indicating its direct association. Stimulation of STAT-1 expression by double-stranded polynucleotides or ectopic expression is shown to induce MUC4 expression, without Y701 phosphorylation of STAT-1. This effect is abrogated by short interfering RNA (siRNA)-mediated inhibition of STAT-1 expression, supporting further the relevance of STAT-1 in MUC4 regulation. In conclusion, our findings identify a novel mechanism for MUC4 regulation in pancreatic cancer cells and unfold new perspectives on the foundation of IFN-γ-dependent gene regulation.Oncogene (2007) 26, 7251–7261; doi:10.1038/sj.onc.1210532; published online 21 May 2007 [ABSTRACT FROM AUTHOR]

Recent evidence suggests that Runt-related transcription factors play a role in different human tumours. In the present study, the localisation of the Runt-related transcription factor-2 (Runx2), its transcriptional activity, as well as its regulation of expression was analysed in human pancreatic ductal adenocarcinoma (PDAC). Quantitative real-time PCR and immunohistochemistry were used for Runx2 expression and localisation analysis. Runt-related transcription factor-2 expression was silenced using specific siRNA oligonucleotides in pancreatic cancer cells (Panc-1) and immortalised pancreatic stellate cells (IPSCs). Overexpression of Runx2 was achieved using a full-length expression vector. TGF-β1, BMP2, and other cytokines were assessed for their potential to regulate Runx2 expression. There was a 6.1-fold increase in median Runx2 mRNA levels in PDAC tissues compared to normal pancreatic tissues (P<0.0001). Runt-related transcription factor-2 was localised in pancreatic cancer cells, tubular complexes, and PanIN lesions of PDAC tissues as well as in tumour-associated fibroblasts/stellate cells. Coculture of IPSCs and Panc-1 cells, as well as treatment with TGF-β1 and BMP2, led to increased Runx2 expression in Panc-1 cells. Runt-related transcription factor-2 overexpression was associated with decreased MMP1 release as well as decreased growth and invasion of Panc-1 cells. These effects were reversed by Runx2 silencing. In conclusion, Runx2 is overexpressed in PDAC, where it is regulated by certain cytokines such as TGF-β1 and BMP2 in an auto- and paracrine manner. In addition, Runx2 has the potential to regulate the transcription of extracellular matrix modulators such as SPARC and MMP1, thereby influencing the tumour microenvironment.British Journal of Cancer (2007) 97, 1106–1115. doi:10.1038/sj.bjc.6603984 www.bjcancer.com Published online 18 September 2007 [ABSTRACT FROM AUTHOR]

MUC4 is a type-1 transmembrane glycoprotein and is overexpressed in many carcinomas. It is a heterodimeric protein of 930 kDa, composed of a mucin-type subunit, MUC4alpha, and a membrane-bound growth factor-like subunit, MUC4beta. MUC4 mRNA contains unique 5' and 3' coding sequences along with a large variable number of tandem repeat (VNTR) domain of 7-19 kb. A direct association of MUC4 overexpression has been established with the degree of invasiveness and poor prognosis of pancreatic cancer. To understand the precise role of MUC4 in pancreatic cancer, we engineered a MUC4 complementary DNA construct, mini-MUC4, whose deduced protein (320 kDa) is comparable with that of wild-type MUC4 (930 kDa) but represents only 10% of VNTR. Stable ectopic expression of mini-MUC4 in two human pancreatic cancer cell lines, Panc1 and MiaPaCa, showed that MUC4 minigene expression follows a biosynthesis and localisation pattern similar to the wild-type MUC4. Expression of MUC4 resulted in increased growth, motility, and invasiveness of the pancreatic cancer cells in vitro. Ultra-structural examination of MUC4-transfected cells showed the presence of increased number and size of mitochondria. The MUC4-expressing cells also demonstrated an enhanced tumorigenicity in an orthotopic xenograft nude mice model, further supporting a direct role of MUC4 in inducing the cancer properties. In conclusion, our results suggest that MUC4 promotes tumorigenicity and is directly involved in growth and survival of the cancer cells. [ABSTRACT FROM AUTHOR]

The article discusses on the molecular mechanisms of pancreatic cancer and its target of treatment. It was said that amidst advances in surgery and oncological therapy regimens, pancreatic cancer stays to encounter diagnostic and therapeutic problems. The aggressive nature of the disease and hard clinical manifestation raise the demands of more effective treatment methods since uncontrolled cell division resulted to inflammation and lengthens changes in the cellular signaling pathways.