To improve the prognosis of patients with pancreatic cancer, new biomarkers are required for earlier, pre-symptomatic diagnosis. Epigenetic mutations take place at the earliest stages of tumorigenesis and therefore offer new approaches for detecting and diagnosing disease. Nucleosomes are the repeating subunits of DNA and histone proteins that constitute human chromatin. Because of their release into the circulation, intact nucleosome levels in serum or plasma can serve as diagnostic disease biomarkers, and elevated levels have been reported in various cancers. However, quantifying nucleosomes in the circulation for cancer detection has been challenging due to nonspecific elevation in sera of patients with benign diseases. Here, we report for the first time differential, disease-associated epigenetic profiles of intact cell-free nucleosomes (cfnucleosomes) containing specific DNA and histone modifications as well as histone variants circulating in the blood. The study comprised serum samples from 59 individuals, including 25 patients with resectable pancreatic cancer, 10 patients with benign pancreatic disease, and 24 healthy individuals using Nucleosomics®, a novel ELISA method. Multivariate analysis defined a panel of five serum cfnucleosome biomarkers that gave an area under the curve (AUC) of 0.95 for the discrimination of pancreatic cancer from healthy controls, which was superior to the diagnostic performance of the common pancreatic tumor biomarker, carbohydrate antigen 19-9 (CA 19-9) with an AUC of 0.87. Combining CA 19-9 with a panel of four cfnucleosome biomarkers gave an AUC of 0.98 with an overall sensitivity of 92 % at 90 % specificity. The present study suggests that global epigenetic profiling of cfnucleosomes in serum using a simple NuQ® immunoassay-based approach can provide novel diagnostic biomarkers in pancreatic cancer.
Epigenetic alterations have been recognized as important contributors to the pathogenesis of PDAC. However, the role of histone variants in pancreatic tumor progression is still not completely understood. The aim of this study was to explore the expression and prognostic significance of histone protein variants in PDAC patients.Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for qualitative analysis of histone variants and histone related post-translational modifications (PTMs) in PDAC and normal pancreatic tissues. Survival analysis was conducted using the Kaplan-Meier method and Cox proportional hazards regression.Histone variant H1.3 was found to be differentially expressed (p = 0.005) and was selected as a PDAC specific histone variant candidate. The prognostic role of H1.3 was evaluated in an external cohort of patients with resected PDAC using immunohistochemistry. Intratumor expression of H1.3 was found to be an important risk factor for overall survival in PDAC, with an adjusted HR value of 2.6 (95% CI 1.1-6.1), p = 0.029.We suggest that the intratumor histone H1.3 expression as reported herein, may serve as a new epigenetic biomarker for PDAC.
Pancreatic cancer is a major cause of cancer-related mortality. The identification of effective biomarkers is essential in order to improve management of the disease. Yes-associated protein 1 (YAP1) is a downstream effector of the Hippo pathway, a signal transduction system implicated in tissue repair and regeneration, as well as tumorigenesis. Here we evaluate the biomarker potential of YAP1 in pancreatic cancer tissue.YAP1 was selected as a possible biomarker for pancreatic cancer from global protein sequencing of fresh frozen pancreatic cancer tissue samples and normal pancreas controls. The prognostic utility of YAP1 was evaluated using mRNA expression data from 176 pancreatic cancer patients in The Cancer Genome Atlas (TCGA), as well as protein expression data from immunohistochemistry analysis of a local tissue microarray (TMA) cohort comprising 140 pancreatic cancer patients. Ingenuity Pathway Analysis was applied to outline the interaction network for YAP1 in connection to the pancreatic tumor microenvironment. The expression of YAP1 target gene products was evaluated after treatment of the pancreatic cancer cell line Panc-1 with three substances interrupting YAP-TEAD interaction, including Super-TDU, Verteporfin and CA3.Mass spectrometry based proteomics showed that YAP1 is the top upregulated protein in pancreatic cancer tissue when compared to normal controls (log2 fold change 6.4; p = 5E-06). Prognostic analysis of YAP1 demonstrated a significant correlation between mRNA expression level data and reduced overall survival (p = 0.001). In addition, TMA and immunohistochemistry analysis suggested that YAP1 protein expression is an independent predictor of poor overall survival [hazard ratio (HR) 1.870, 95% confidence interval (CI) 1.224-2.855, p = 0.004], as well as reduced disease-free survival (HR 1.950, 95% CI 1.299-2.927, p = 0.001). Bioinformatic analyses coupled with in vitro assays indicated that YAP1 is involved in the transcriptional control of target genes, associated with extracellular matrix remodeling, which could be modified by selected substances disrupting the YAP1-TEAD interaction.Our findings indicate that YAP1 is an important prognostic biomarker for pancreatic cancer and may play a regulatory role in the remodeling of the extracellular matrix.
Calcium-activated chloride channel regulator 1 (CLCA1) belongs to a group of secreted self-cleaving proteins, which activate calcium-dependent chloride channels. CLCA1 has been shown to participate in the pathogenesis of inflammatory airway diseases such as asthma. Recently, additional functions of CLCA1 have been unveiled, including its metalloprotease property and involvement in mucus homeostasis and immune modulation. Emerging evidence suggests that CLCA1 may also be involved in the pathophysiology of colorectal, pancreatic and ovarian cancer. There is growing interest in utilizing CLCA1 as a diagnostic, prognostic and predictive biomarker, as well as a potential therapeutic target. In this review, the functional role of CLCA1, with a particular focus on cancer, is described.
Acute lung injury (ALI) is an important cause of mortality in critically ill patients. Acute pancreatitis (AP) is one of the risk factors for developing this syndrome. Among the inflammatory cells, macrophages have a key role in determining the severity of the acute lung injury. In the lungs, macrophages constitute a heterogeneous cell population distributed in different compartments. Changes in not only the macrophage count, but also in their phenotype have been seen during the course of lung injury. A murine ductal ligation model of acute pancreatitis showed substantial morphological changes in the pancreas and lungs. Immunohistochemistry showed neutrophil recruitment into both organs after 9 hours and later on. F4/80+ cells in the pancreas increased in the ligated animals, though there was not a significant difference in their number in the lungs as compared to sham operated animals. Flow cytometry analysis of lung macrophages demonstrated an enrichment of F4/80− CD68+CCR2+ and F4/80− CD68+CD206+ lung macrophages in ligated animals (AP) as compared to the sham operated group. The level of interleukin-6 in plasma increased 3 hours after ligation compared to the sham operated group, as a first indicator of a systemic inflammatory response. This study suggests a role for F4/80− CD68+ macrophages in the pathogenesis of acute lung injury in acute pancreatitis. Studying lung macrophages for different phenotypic markers, their polarization, activation and recruitment, in the context of acute lung injury, is a novel area to potentially identify interventions which may improve the outcome of acute lung injury.
e15708 Background: Pancreatic cancer is a heterogeneous disease with an aggressive clinical course. Most patients are detected late due to the insidious onset of symptoms and lack of effective molecular markers. The purpose of this study was to develop protein markers for improved prognostication and non-invasive diagnosis. Methods: A mass spectrometry (MS)-based discovery approach was applied to pancreatic cancer tissues and healthy pancreas. In the verification phase, extracellular proteins with differential expression were further quantified in targeted mode using parallel reaction monitoring (PRM). Next, a tissue microarray (TMA) cohort including 140 pancreatic cancer resection specimens was constructed, in order to validate protein expression status and investigate potential prognostic implications. The levels of protein candidates were finally assessed in a panel of 80 serum samples with ELISA. Results: Protein sequencing with nano-liquid chromatography tandem MS (nano-LC-MS/MS) and targeted PRM identified alpha-1-acid glycoprotein 1 (AGP1) as a potential pancreatic cancer biomarker. Using TMA and immunohistochemistry, AGP1 expression was significantly associated with shorter overall survival (HR = 2.217; 95% CI 1.296-3.794, p = 0.004). Multivariable analysis confirmed the results (HR = 1.867; 95% CI 1.078-3.235, p = 0.026). Circulating levels of AGP1 yielded an area under the curve (AUC) of 0.85 for the discrimination of resectable pancreatic cancer and IPMN from healthy controls. Combining AGP1 with CA 19-9 displayed an AUC of 0.98 with an overall sensitivity of 96% at 90% specificity. Conclusions: This study suggests that AGP1 is a valid biomarker for pancreatic cancer.
Metabolic rewiring is a key feature of cancer cells to support the demands of growth and proliferation. The metabolism of amino acids is altered in many cancers, including pancreatic cancer. The cellular uptake of amino acids is regulated by amino acid transporters, such as L-type amino acid transporter 1 (LAT1). Accumulating evidence suggests that LAT1 is overexpressed in pancreatic cancer and confers a poor prognosis. Here we discuss the prospects of utilizing LAT1 as a novel target for pancreatic cancer therapy.