Serum glycoprotein markers of cancer using an ion mobility/mass spec approach

描述（由申请人提供）：胰腺腺癌是美国癌症相关死亡的第四大原因(1)，与4%的五年生存率相关。大多数患者在发病时都有不可切除的疾病，尽管少数患者（10-20%）被发现有早期可切除的胰腺癌。一种早期检测胰腺癌的方法将提供长期生存甚至治愈的前景。一种高度特异性的非侵入性检查可以区分早期胰腺腺癌和不可切除的疾病，以及慢性胰腺炎和其他非胰腺癌症和炎症状况，可能提供一种有价值的临床工具。许多类型的恶性肿瘤已被证明在特定的糖蛋白上具有独特的聚糖部分，与在正常状态或其他疾病中可以在血清中检测到的相同蛋白质相比。在提出的工作中，我们将使用基于质谱的分析来提高检测疾病状态之间聚糖结构变化的分析特异性。我们将使用一个平台，包括从血清中选定蛋白质的抗体捕获，然后去糖基化并从这些蛋白质中收集聚糖。然后用离子迁移率/串联质谱法分析聚糖，该方法对聚糖结构的细微变化也很敏感。离子迁移方法可以提供包括糖型在内的聚糖的快速分离，并且使用串联质谱检测可以很容易地观察到糖水平上聚糖结构作为疾病的函数的变化。该方法可用于同时分析多种糖蛋白变化，可用于使用离子迁移率方法和质谱技术的组合分离能力对大量样品进行高通量分析。建议的工作将包括研究15种抗体/蛋白质组合，这些组合是根据我们初步的糖阵列研究选择的。我们假设在良性胰腺粘液囊性肿瘤（MCNs）和导管内乳头状粘液瘤（ipmn）、长期II型糖尿病患者、慢性胰腺炎患者和胰腺癌患者的血清样本中可以观察到独特的糖基化模式。为了验证这一假设，我们将从5个疾病组中各使用50个血清样本来计算敏感性和特异性，以确定应该进入盲法测试集的标记物，并确定决策的切入点。我们还将筛选50份其他癌症的样本进行比较，包括食管癌、结直肠癌、肝细胞癌和卵巢癌。我们假设胰腺癌的糖基化模式是独特的，不与其他癌症重叠。

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: 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.