Robust acinar cell transgene expression of CreErT via BAC recombineering

Pancreatic acinar cells are critical in gastrointestinal physiology and pancreatitis and may be involved in pancreatic cancer. Previously, a short rat pancreatic elastase promoter has been widely utilized to control acinar cell transgene expression. However, this partial sequence does not confer robust and stable expression. In this study, we tested the hypothesis that a transgene employing bacterial-artificial-chromosome (BAC) technology to express a tamoxifen-regulated Cre recombinase from a full-length mouse elastase gene (BAC-Ela-CreErT) would be more robust and stable. When founders were crossed with Rosa26 reporter mice nearly 100% of acini expressed Β-galactosidase after tamoxifen treatment. The expression was specific for pancreatic acinar cells and these characteristics have remained stable for 2 years. However, because of high levels of expression in differentiated acinar cells, this construct is tamoxifen independent in ∼50% of adult acinar cells. This model of pancreatic acinar specific Cre expression is a powerful tool for future transgenic and knockout studies. genesis 46:390–395, 2008. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60895/1/20411_ftp.pd

Targeting Pancreatic Ductal Adenocarcinoma Acidic Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA, accounting for ~40,000 deaths annually. The dismal prognosis for PDAC is largely due to its late diagnosis. Currently, the most sensitive diagnosis of PDAC requires invasive procedures, such as endoscopic ultrasonography, which has inherent risks and accuracy that is highly operator dependent. Here we took advantage of a general characteristic of solid tumors, the acidic microenvironment that is generated as a by-product of metabolism, to develop a novel approach of using pH (Low) Insertion Peptides (pHLIPs) for imaging of PDAC. We show that fluorescently labeled pHLIPs can localize and specifically detect PDAC in human xenografts as well as PDAC and PanIN lesions in genetically engineered mouse models. This novel approach may improve detection, differential diagnosis and staging of PDAC

Identification of a Specific Vimentin Isoform That Induces an Antibody Response in Pancreatic Cancer

Pancreatic cancer has a poor prognosis, in part due to lack of early detection. The identification of circulating tumor antigens or their related autoantibodies provides a means for early cancer diagnosis. We have used a proteomic approach to identify proteins that commonly induce a humoral response in pancreatic cancer. Proteins from a pancreatic adenocarcinoma cell line (Panc-1) were subjected to two-dimensional PAGE, followed by Western blot analysis in which individual sera were tested for autoantibodies. Sera from 36 newly diagnosed patients with pancreatic cancer, 18 patients with chronic pancreatitis and 15 healthy subjects were analyzed. Autoantibodies were detected against a protein identified by mass spectrometry as vimentin, in sera from 16/36 patients with pancreatic cancer (44.4%). Only one of 18 chronic pancreatitis patients and none of the healthy controls exhibited reactivity against this vimentin isoform. Interestingly, none of several other isoforms of vimentin detectable in 2-D gels exhibited reactivity with patient sera. Vimentin protein expression levels were investigated by comparing the integrated intensity of spots visualized in 2-D PAGE gels of various cancers. Pancreatic tumor tissues showed greater than a 3-fold higher expression of total vimentin protein than did the lung, colon, and ovarian tumors that were analyzed. The specific antigenic isoform was found at 5–10 fold higher levels. The detection of autoantibodies to this specific isoform of vimentin may have utility for the early diagnosis of pancreatic cancer

Human Pancreatic Acinar Cells Do Not Respond to Cholecystokinin

Pancreatic secretion can be influenced by cholecystokinin (CCK) either directly via actions on acinar cells or indirectly via actions on nerves. The presence and functional roles of CCK receptors on human pancreatic acinar cells remains unclear. In the current study human pancreatic acini were isolated and then treated with CCK-8, gastrin and/or carbachol. Functional parameters were measured including intracellular [Ca2+] and amylase secretion. It was observed that human acini did not respond to CCK agonists but did respond to carbachol with robust increases in functional parameters. Adenoviral-mediated gene transfer of CCK1 or CCK2 receptors to the human cells resulted in cell responses to CCK agonists. In order to determine the reason for the lack of responsiveness of the human acini, expression of receptor mRNAs was determined using quantitative RT-PCR and localized by in situ hybridization. mRNA levels for CCK1 receptors were ∼30 times lower than those of CCK2 receptors, which were ∼10 times lower than those of m3 Ach receptors as measured by quantitative PCR. Neither CCK1 nor CCK2 receptors were localized in adult human pancreas by i n situ hybridization. These results indicate that human pancreatic acinar cells do not respond directly to CCK receptor activation and this is likely due to an insufficient level of receptor expression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73903/1/j.1600-0773.2002.910610.x.pd

Detection of pancreatic cancer tumours and precursor lesions by cathepsin E activity in mouse models.

ABSTRACT Background and Aims Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA. Surgical resection is the only effective treatment; however, only 20% of patients are candidates for surgery. The ability to detect early PDAC would increase the availability of surgery and improve patient survival. This study assessed the feasibility of using the enzymatic activity of cathepsin E (Cath E), a protease highly and specifically expressed in PDAC, as a novel biomarker for the detection of pancreas-bearing pancreatic intraepithelial neoplasia (PanIN) lesions and PDAC. Methods Pancreas from normal, chronic pancreatitis and PDAC patients was assessed for Cath E expression by quantitative real-time PCR and immunohistochemistry. Human PDAC xenografts and genetically engineered mouse models (GEMM) of PDAC were injected with a Cath E activity selective fluorescent probe and imaged using an optical imaging system. Results The specificity of Cath E expression in PDAC patients and GEMM of pancreatic cancer was confirmed by quantitative real-time PCR and immunohistochemistry. The novel probe for Cath E activity specifically detected PDAC in both human xenografts and GEMM in vivo. The Cath E sensitive probe was also able to detect pancreas with PanIN lesions in GEMM before tumour formation. Conclusions The elevated Cath E expression in PanIN and pancreatic tumours allowed in-vivo detection of human PDAC xenografts and imaging of pancreas with PanIN and PDAC tumours in GEMM. Our results support the usefulness of Cath E activity as a potential molecular target for PDAC and early detection imaging. Despite great efforts to help patients with pancreatic ductal adenocarcinoma (PDAC) in the past few years, this disease remains devastating with the worst outcome of all major cancers. In the USA, PDAC ranks 10th in terms of incidence, but for both men and women, it is fourth in terms of cancer deaths. Although many molecular biomarker candidates of PDAC have been identified, 3 biomarkers with the necessary sensitivity and specificity for early detection are still lacking. 4e6 The most widely utilised blood-based biomarker is CA 19-9, which is not expressed in all patients, is not highly specific as it is elevated in other gastrointestinal cancers, and is not useful for the detection of early disease. 7 8 Furthermore, CA 19-9 levels do not provide information about the localisation of the disease nor the existence of metastases. The most sensitive diagnosis of PDAC currently requires invasive imaging procedures such as endoscopic ultrasonography, which Significance of this study What is already known about this subject? < No highly specific and sensitive biomarkers are clinically available for the detection of PDAC at an early stage. < Cath E is highly overexpressed in many cancers including PDAC. < A Cath E selective peptide was recently identified that specifically detects its enzymatic activity. What are the new findings? < We demonstrate that the elevated levels of Cath E expression in early pancreatic cancer lesions and pancreatic tumours could be exploited for PDAC detection. < We illustrate that the detection and localisation of PDAC in mouse xenografts and GEMM was possible utilising the outstanding specificity of a novel Cath E-activatable imaging probe. How might it impact on clinical practice in the foreseeable future? < The ability to detect and visualise pancreatic tumours and PanIN in PDAC by virtue of Cath E activity sensitive probes in preclinical mouse models suggests that modifications of this approach will be useful for the early detection and management of this deadly cancer in patients. < The specificity of Cath E activity for PDAC suggests that this enzymatic activity will be useful in the future for the development of novel therapeutics or theranostics. Cruz-Monserrate Z, Abd-Elgaliel WR, Grote T, et al. Gut (2011)

Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice

New-onset diabetes in patients with pancreatic cancer is likely to be a paraneoplastic phenomenon caused by tumor-secreted products. We aimed to identify the diabetogenic secretory product(s) of pancreatic cancer. Methods: Using microarray analysis, we identified adrenomedullin as a potential mediator of diabetes in patients with pancreatic cancer. Adrenomedullin was up-regulated in pancreatic cancer cell lines, in which supernatants reduced insulin signaling in beta cell lines. We performed quantitative reverse-transcriptase polymerase chain reaction and immunohistochemistry on human pancreatic cancer and healthy pancreatic tissues (controls) to determine expression of adrenomedullin messenger RNA and protein, respectively. We studied the effects of adrenomedullin on insulin secretion by beta cell lines and whole islets from mice and on glucose tolerance in pancreatic xenografts in mice. We measured plasma levels of adrenomedullin in patients with pancreatic cancer, patients with type 2 diabetes mellitus, and individuals with normal fasting glucose levels (controls). Results: Levels of adrenomedullin messenger RNA and protein were increased in human pancreatic cancer samples compared with controls. Adrenomedullin and conditioned media from pancreatic cell lines inhibited glucose-stimulated insulin secretion from beta cell lines and islets isolated from mice; the effects of conditioned media from pancreatic cancer cells were reduced by small hairpin RNA-mediated knockdown of adrenomedullin. Conversely, overexpression of adrenomedullin in mice with pancreatic cancer led to glucose intolerance. Mean plasma levels of adrenomedullin (femtomoles per liter) were higher in patients with pancreatic cancer compared with patients with diabetes or controls. Levels of adrenomedullin were higher in patients with pancreatic cancer who developed diabetes compared those who did not. Conclusions: Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice.Fil: Aggarwal, Gaurav. Mayo Clinic College of Medicine; Estados UnidosFil: Ramachandran, Vijaya. University of Texas Health Science Center at Houston. University of Texas Md Anderson Cancer Center; Estados UnidosFil: Javeed, Naureen. Mayo Clinic College of Medicine; Estados UnidosFil: Arumugam, Thiruvengadam. University of Texas Health Science Center at Houston. University of Texas Md Anderson Cancer Center; Estados UnidosFil: Dutta, Shamit. Mayo Clinic College of Medicine; Estados UnidosFil: Klee, George G.. Mayo Clinic College of Medicine; Estados UnidosFil: Klee, Eric W.. Mayo Clinic College of Medicine; Estados UnidosFil: Smyrk, Thomas C.. Mayo Clinic College of Medicine; Estados UnidosFil: Bamlet, William. Mayo Clinic College of Medicine; Estados UnidosFil: Han, Jing Jing. Mayo Clinic College of Medicine; Estados UnidosFil: Rumie Vittar, Natalia Belen. Mayo Clinic College of Medicine; Estados Unidos. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Biología Molecular. Sección Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: De Andrade, Mariza. Mayo Clinic College of Medicine; Estados UnidosFil: Mukhopadhyay, Debabrata. Mayo Clinic College of Medicine; Estados UnidosFil: Petersen, Gloria M.. Mayo Clinic College of Medicine; Estados UnidosFil: Fernandez Zapico, Martin Ernesto. Mayo Clinic College of Medicine; Estados UnidosFil: Logsdon, Craig D.. University of Texas Health Science Center at Houston. University of Texas Md Anderson Cancer Center; Estados UnidosFil: Chari, Suresh T.. Mayo Clinic College of Medicine; Estados Unido

StellaTUM: current consensus and discussion on pancreatic stellate cell research

The field of pancreatic stellate cell (PSC) biology is very young, as the essential in-vitro tools to study these cells (ie, methods to isolate and culture PSC) were only developed as recently as in 1998. Nonetheless, there has been an exponential increase in research output in this field over the past decade, with numerous research groups around the world focusing their energies into elucidating the biology and function of these cells. It is now well established that PSC are responsible for producing the stromal reaction (fibrosis) of two major diseases of the pancreas—chronic pancreatitis and pancreatic cancer. Despite exponentially increasing data, the methods for studying PSC remain variable. Although within individual laboratories methods are consistent, different methodologies used by various research groups make it difficult to compare results and conclusions. This article is not a review article on the functions of PSC. Instead, members of the Pancreatic Star Alliance (http://www.pancreaticstaralliance.com) discuss here and consolidate current knowledge, to outline and delineate areas of consensus or otherwise (eg, with regard to methodological approaches) and, more importantly, to identify essential directions for future research

Increased CDC20 expression is associated with pancreatic ductal adenocarcinoma differentiation and progression

<p>Abstract</p> <p>Purpose</p> <p>Cell division cycle 20 (CDC20) homolog is an anaphase-promoting complex activator that is essential for cell division, but whether its expression in pancreatic ductal adenocarcinoma (PDAC) is significant is unknown. In this retrospective study, we determined whether aberrant CDC20 expression can be used as a biomarker in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis and whether its expression reflects clinical progression.</p> <p>Experimental design</p> <p>We compared CDC20 expression levels in normal, cancerous, and inflamed pancreatic tissues from stage II PDAC patients with clinical outcomes and determined CDC20 levels in seven PDAC cell lines. CDC20 was identified using a cDNA microarray database containing gene expression profiles for PDAC tissues and cell lines and chronic pancreatitis and normal pancreas tissues. Its expression was confirmed by real-time quantitative reverse-transcriptase-polymerase chain reaction (qRT-PCR). An immunohistochemical analysis of tissue microarrays from resected PDAC tumors and paired benign pancreatic tissues was done and CDC20 levels were correlated with clinical outcome.</p> <p>Results</p> <p>Fifty-six patients were included in this study. A microarray analysis revealed 5-fold higher CDC20 expression in PDAC tissue than in chronic pancreatitis tissue. A qRT-PCR analysis confirmed a mean 20-fold higher CDC20 level in PDAC tissue than in normal pancreas and pancreatitis tissue. RNA and protein CDC20 expression was detected in several PDAC cell lines. An immunohistochemical analysis revealed higher CDC20 protein expression levels in PDAC tissue than in normal pancreas tissue, and high CDC20 expression was associated with poor differentiation (<it>P </it>= 0.020) and a significantly lower 5-year recurrence-free survival rate (<it>P </it>= 0.039); we also found a trend toward a shorter overall survival duration.</p> <p>Conclusions</p> <p>Aberrant CDC20 expression may play an important role in PDAC tumorigenesis and progression and may thus be useful as a marker of disease progression and prognosis and as a therapeutic target.</p

An organizing framework for informal caregiver interventions: detailing caregiving activities and caregiver and care recipient outcomes to optimize evaluation efforts

Abstract Background Caregiver interventions may help improve the quality of informal care. Yet the lack of a systematic framework specifying the targets and outcomes of caregiver interventions hampers our ability to understand what has been studied, to evaluate existing programs, and to inform the design of future programs. Our goal was to develop an organizing framework detailing the components of the caregiving activities and the caregiver and care recipient outcomes that should be affected by an intervention. In so doing, we characterize what has been measured in the published literature to date and what should be measured in future studies to enable comparisons across interventions and across time. Methods Our data set comprises 121 reports of caregiver interventions conducted in the United States and published between 2000 and 2009. We extracted information on variables that have been examined as primary and secondary outcomes. These variables were grouped into categories, which then informed the organizing framework. We calculated the frequency with which the interventions examined each framework component to identify areas about which we have the most knowledge and under-studied areas that deserve attention in future research. Results The framework stipulates that caregiver interventions seek to change caregiving activities, which in turn affect caregiver and care recipient outcomes. The most frequently assessed variables have been caregiver psychological outcomes (especially depression and burden) and care recipient physical and health care use outcomes. Conclusions Based on the organizing framework, we make three key recommendations to guide interventions and inform research and policy. First, all intervention studies should assess quality and/or quantity of caregiving activities to help understand to what extent and how well the intervention worked. Second, intervention studies should assess a broad range of caregiver and care recipient outcomes, including considering whether expanding to economic status and health care use of the caregiver can be accommodated, to ease subsequent economic evaluations of caregiving. Third, intervention studies should measure a common set of outcomes to facilitate cross-time and cross-study comparisons of effectiveness