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Background & Aims: Early detection of pancreatic ductal adenocarcinoma (PDAC) allows for surgical resection and increases patient survival times. Imaging agents that bind and amplify the signal of neovascular proteins in neoplasms can be detected by ultrasound, enabling accurate detection of small lesions. We searched for new markers of neovasculature in PDAC and assessed their potential for tumor detection by ultrasound molecular imaging., Methods: Thymocyte differentiation antigen 1 (Thy1) was identified as a specific biomarker of PDAC neovasculature by proteomic analysis. Up-regulation in PDAC was validated by immunohistochemical analysis of pancreatic tissue samples from 28 healthy individuals, 15 with primary chronic pancreatitis tissues, and 196 with PDAC. Binding of Thy1-targeted contrast microbubbles was assessed in cultured cells, in mice with orthotopic PDAC xenograft tumors expressing human Thy1 on the neovasculature, and on the neovasculature of a genetic mouse model of PDAC., Results: Based on immunohistochemical analyses, levels of Thy1 were significantly higher in the vascular of human PDAC than chronic pancreatitis (P = .007) or normal tissue samples (P < .0001). In mice, ultrasound imaging accurately detected human Thy1-positive PDAC xenografts, as well as PDACs that express endogenous Thy1 in genetic mouse models of PDAC., Conclusions: We have identified and validated Thy1 as a marker of PDAC that can be detected by ultrasound molecular imaging in mice. The development of a specific imaging agent and identification of Thy1 as a new biomarker could aid in the diagnosis of this cancer and management of patients., (Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Better pancreatic cyst fluid biomarkers are needed., Objective: To determine whether metabolomic profiling of pancreatic cyst fluid would yield clinically useful cyst fluid biomarkers., Design: Retrospective study., Setting: Tertiary-care referral center., Patients: Two independent cohorts of patients (n = 26 and n = 19) with histologically defined pancreatic cysts., Intervention: Exploratory analysis for differentially expressed metabolites between (1) nonmucinous and mucinous cysts and (2) malignant and premalignant cysts was performed in the first cohort. With the second cohort, a validation analysis of promising identified metabolites was performed., Main Outcome Measurements: Identification of differentially expressed metabolites between clinically relevant cyst categories and their diagnostic performance (receiver operating characteristic [ROC] curve)., Results: Two metabolites had diagnostic significance-glucose and kynurenine. Metabolomic abundances for both were significantly lower in mucinous cysts compared with nonmucinous cysts in both cohorts (glucose first cohort P = .002, validation P = .006; and kynurenine first cohort P = .002, validation P = .002). The ROC curve for glucose was 0.92 (95% confidence interval [CI], 0.81-1.00) and 0.88 (95% CI, 0.72-1.00) in the first and validation cohorts, respectively. The ROC for kynurenine was 0.94 (95% CI, 0.81-1.00) and 0.92 (95% CI, 0.76-1.00) in the first and validation cohorts, respectively. Neither could differentiate premalignant from malignant cysts. Glucose and kynurenine levels were significantly elevated for serous cystadenomas in both cohorts., Limitations: Small sample sizes., Conclusion: Metabolomic profiling identified glucose and kynurenine to have potential clinical utility for differentiating mucinous from nonmucinous pancreatic cysts. These markers also may diagnose serous cystadenomas., (Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: Accurate tests to diagnose adenocarcinoma and high-grade dysplasia among mucinous pancreatic cysts are clinically needed. This study evaluated the diagnostic utility of amphiregulin (AREG) as a pancreatic cyst fluid biomarker to differentiate non-mucinous, benign mucinous, and malignant mucinous cysts., Methods: A single-center retrospective study to evaluate AREG levels in pancreatic cyst fluid by ELISA from 33 patients with a histological gold standard was performed., Results: Among the cyst fluid samples, the median (IQR) AREG levels for non-mucinous (n = 6), benign mucinous (n = 15), and cancerous cysts (n = 15) were 85 pg/ml (47-168), 63 pg/ml (30-847), and 986 pg/ml (417-3160), respectively. A significant difference between benign mucinous and malignant mucinous cysts was observed (p = 0.025). AREG levels greater than 300 pg/ml possessed a diagnostic accuracy for cancer or high-grade dysplasia of 78% (sensitivity 83%, specificity 73%)., Conclusion: Cyst fluid AREG levels are significantly higher in cancerous and high-grade dysplastic cysts compared to benign mucinous cysts. Thus AREG exhibits potential clinical utility in the evaluation of pancreatic cysts.

Objectives: The purpose of this study was to screen for genes related to lymph node metastasis by comparing the differences in the expression profile between pancreatic cancer with lymph node metastasis and one without, and to predict the invasiveness and the progression of pancreatic cancer on the basis of these findings., Methods: The total RNA of the tissues was extracted from 10 pancreatic cancer specimens, including those with lymph node metastasis and those with no metastasis. It was studied by means of a DNA microarray (oligo chip) consisting of 37,842 genes. We screened out 1.5-fold or more differential gene expressions in at least 5 pairs of samples. We classified both samples and genes using a 2-way clustering analysis. The screened-out genes were identified using real-time polymerase chain reaction., Results: We identified 194 genes, including 66 overexpressed and 128 underexpressed genes, in pancreatic cancer with lymph node metastasis. Among them, we identified some genes related to lymph node metastasis in patients with pancreatic cancer: oncogenes, tumor suppressor genes, apoptosis and antiapoptosis genes, tumor angiogenesis factors, and cell cycle regulators. Genes promoting the growth of tumor cells were highly expressed in lymph node-positive pancreatic cancer, whereas genes inducing apoptosis were underexpressed., Conclusions: We have identified genes that may play an important role in metastasis and survival in patients with pancreatic cancer. These results provide new insight into the study of human pancreatic cancer metastasis, including lymph node metastasis, and ultimately may lead to improving early diagnosis and discovering innovative therapeutic approaches for cancer.

Background: Cancers of the pancreas originate from both the endocrine and exocrine elements of the organ, and represent a major cause of cancer-related death. This study provides a comprehensive assessment of gene expression for pancreatic tumors, the normal pancreas, and nonneoplastic pancreatic disease., Methods/results: DNA microarrays were used to assess the gene expression for surgically derived pancreatic adenocarcinomas, islet cell tumors, and mesenchymal tumors. The addition of normal pancreata, isolated islets, isolated pancreatic ducts, and pancreatic adenocarcinoma cell lines enhanced subsequent analysis by increasing the diversity in gene expression profiles obtained. Exocrine, endocrine, and mesenchymal tumors displayed unique gene expression profiles. Similarities in gene expression support the pancreatic duct as the origin of adenocarcinomas. In addition, genes highly expressed in other cancers and associated with specific signal transduction pathways were also found in pancreatic tumors., Conclusion: The scope of the present work was enhanced by the inclusion of publicly available datasets that encompass a wide spectrum of human tissues and enabled the identification of candidate genes that may serve diagnostic and therapeutic goals.

Pancreatic stellate cells (PaSCs) are myofibroblast-like cells found in the areas of the pancreas that have exocrine function. PaSCs are regulated by autocrine and paracrine stimuli and share many features with their hepatic counterparts, studies of which have helped further our understanding of PaSC biology. Activation of PaSCs induces them to proliferate, to migrate to sites of tissue damage, to contract and possibly phagocytose, and to synthesize ECM components to promote tissue repair. Sustained activation of PaSCs has an increasingly appreciated role in the fibrosis that is associated with chronic pancreatitis and with pancreatic cancer. Therefore, understanding the biology of PaSCs offers potential therapeutic targets for the treatment and prevention of these diseases.

GP2 is the major membrane protein present in secretory granules of the exocrine pancreas. GP2's function is unknown, but a role in digestive enzyme packaging or secretion from secretory granules has been proposed. In addition, GP2 has been proposed to influence endocytosis and membrane recycling following stimulated secretion. Adenovirus-mediated GP2 overexpression in the rat pancreatic cell line AR4-2J was used to study its impact on digestive enzyme secretion and membrane recycling. Immunoelectron microscopy showed that GP2 and amylase co-localized in secretory granules in infected AR4-2J cells. CCK-8 stimulation resulted in a fourfold increase in amylase secretion with or without GP2 expression. GP2 expression also did not influence endocytosis following CCK-8 stimulation. Thus, GP2 expression in AR4-2J cells does not affect amylase packaging in secretory granules or stimulated secretion. GP2 expression also does not influence membrane recycling in response to stimulated stimulation in AR4-2J cells.

Context: Blood tests possessing higher diagnostic accuracy are needed for all the major pancreatic diseases. Glycoprotein 2 (GP2) is a protein that is specifically expressed by the pancreatic acinar cell and that has previously shown promise as a diagnostic marker in animal models of acute pancreatitis., Objective: This study describes the development of an assay for GP2, followed by the determination of plasma GP2 levels in patients with acute pancreatitis, chronic pancreatitis, and pancreatic cancer., Design: Rabbit polyclonal antisera and mouse monoclonal antibodies were generated against human GP2 and used to develop an enzyme-linked immunosorbent assay. The assay was tested in patients with an admitting diagnosis of pancreatic disease at 2 tertiary care facilities. The diagnosis of acute or chronic pancreatitis and pancreatic cancer was determined using previously established criteria that incorporated symptoms, radiology, pathology, and serology. Plasma GP2 levels were determined in 31 patients with acute pancreatitis, 16 patients with chronic pancreatitis, 36 patients with pancreatic cancer, and 143 control subjects without pancreatic disease. Amylase and lipase levels were also determined in patients with acute pancreatitis., Results: The GP2 assay's sensitivity values were 0.94 for acute pancreatitis, 0.81 for chronic pancreatitis, and 0.58 for pancreatic cancer, which were greater than the 0.71 for acute pancreatitis and 0.43 for chronic pancreatitis (P =.02) observed for amylase. The lipase assay sensitivity for acute pancreatitis was 0.66. The accuracy of the GP2 assay was greater than that of the amylase or lipase assays for acute pancreatitis (GP2 vs lipase, P =.004; GP2 vs amylase, P =.003) when analyzed using receiver operator characteristic curves. When daily serial blood samples were obtained for 13 patients with acute pancreatitis, GP2 levels remained abnormally elevated for at least 1 day longer than the amylase or lipase levels., Conclusion: The GP2 assay is a useful new marker for acute and chronic pancreatitis.

Pancreatic cancer is the fifth leading cause of cancer death in the United States. We used cDNA microarrays to analyze global gene expression patterns in 14 pancreatic cancer cell lines, 17 resected infiltrating pancreatic cancer tissues, and 5 samples of normal pancreas to identify genes that are differentially expressed in pancreatic cancer. We found more than 400 cDNAs corresponding to genes that were differentially expressed in the pancreatic cancer tissues and cell lines as compared to normal pancreas. These genes that tended to be expressed at higher levels in pancreatic cancers were associated with a variety of processes, including cell-cell and cell-matrix interactions, cytoskeletal remodeling, proteolytic activity, and Ca(++) homeostasis. Two prominent clusters of genes were related to the high rates of cellular proliferation in pancreatic cancer cell lines and the host desmoplastic response in the resected pancreatic cancer tissues. Of 149 genes identified as more highly expressed in the pancreatic cancers compared with normal pancreas, 103 genes have not been previously reported in association with pancreatic cancer. The expression patterns of 14 of these highly expressed genes were validated by either immunohistochemistry or reverse transcriptase-polymerase chain reaction as being expressed in pancreatic cancer. The overexpression of one gene in particular, 14-3-3 sigma, was found to be associated with aberrant hypomethylation in the majority of pancreatic cancers analyzed. The genes and expressed sequence tags presented in this study provide clues to the pathobiology of pancreatic cancer and implicate a large number of potentially new molecular markers for the detection and treatment of pancreatic cancer.