Pancreatic adenocarcinoma is the 4th leading cause of cancer-related death in the United States (1) and is associated with a 4% five-year survival rate. Most patients have unresectable disease at presentation although a small minority of patients (10-20%) is found to have early resectable pancreatic cancer. A method for early-stage detection of pancreatic cancer would provide a prospect of long-term survival and even curability. A highly specific noninvasive test that can differentiate early pancreatic adenocarcinoma from unresectable disease, as well as chronic pancreatitis and other non-pancreatic cancers and inflammatory conditions may provide a valuable clinical tool. Many types of malignancies have been shown to possess unique glycan moieties on specific glycoproteins in comparison to the same proteins found in normal states or other diseases that can be detected in the serum. In the proposed work, we will use a mass spec based assay to enhance the analytical specificity for detecting changes in glycan structures between disease states. We will use a platform involving an antibody capture of selected proteins from serum followed by deglycosylation and collection of the glycans from these proteins. The glycans will then be analyzed by an ion mobility/tandem mass spectrometry method which is sensitive to even subtle changes in glycan structure. The ion mobility method can provide a rapid separation of the glycans including glycoforms and the use of tandem mass spec detection can readily observe changes in the glycan structure at the sugar level as a function of disease. The method can be multiplexed to analyze several glycoprotein changes simultaneously where it can be used for high-throughput analysis of a large number of samples using the combined separation capabilities of the ion mobility method and mass spec techniques. The proposed work will involve studying fifteen antibody/protein combinations which were selected based on our preliminary glycoarray studies. We hypothesize that unique glycosylation patterns can be observed in proteins from serum samples of patients with benign pancreatic mucinous cystic neoplasms (MCNs) and intraductal papillary mucinous neoplasms (IPMNs), patients with long-term type II diabetes, patients with chronic pancreatitis, and patients with pancreatic cancer. To address this hypothesis, we will use 50 serum samples from each of the five disease groups to calculate sensitivity and specificity, to identify markers that should be advanced to a blinded test set and to define cut- points for decision making. We will also screen for comparison 50 samples each of other cancers that are archived including esophageal, colorectal, hepatocellular, and ovarian cancers. We hypothesize that the glycosylation patterns of pancreatic cancer are unique and do not overlap with other cancers.
If this work is successful then it will lead to potential markers that can be used for future pre-validation studies for the early detection of pancreatic cancer based upon an antibody/ion mobility/tandem mass spectrometry assay that will reveal unique changes that can be detected in patient serum.
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