Tissue and Tumor Specific Glycosylation of Proteins

描述（由申请人提供）：蛋白糖基化模式改变和血清蛋白水平升高通常是人类疾病的标志。糖蛋白γ-谷氨酰转肽酶（GGT）的血清水平升高常见于肝脏和胰腺肿瘤患者以及非恶性形式的肝脏和胰腺疾病患者。越来越多的数据表明，GGT具有组织特异性和肿瘤特异性糖型，可用于区分癌症患者和其他疾病患者。我的研究将集中在GGT的组织和肿瘤特异性聚糖的鉴定和表征。本研究有三个具体的目标，其中包括使用最先进的荧光HPLC和质谱技术进行糖分析。第一个具体目标是鉴定从正常胰腺和肝脏组织分离的GGT上的组织特异性糖型。第二个具体目标是鉴定从胰腺和肝脏肿瘤分离的GGT上的肿瘤特异性聚糖种类，以及脱落到这些恶性肿瘤患者血清中的GGT上的肿瘤特异性聚糖种类。该提案的第三个具体目的是开发针对GGT上的组织和肿瘤特异性糖表位的抗体，并评估这些抗体用于检测来自非患病个体和诊断为胰腺癌、肝细胞癌以及胰腺和肝脏的非恶性疾病的患者的血清中的组织和肿瘤特异性GGT种类的灵敏度和特异性。这些研究还将提供深入了解肿瘤发生过程中GGT从细胞膜释放到血清中的机制。胰腺癌或肝癌的及时准确诊断对于最大限度地提高治疗效果至关重要。这项工作将建立一个基于血清的免疫测定的早期检测这些恶性肿瘤使用GGT脱落到血清中的糖表位的发展的基础。简单总结：诊断为胰腺癌或肝癌的患者的生存率非常低。这在很大程度上是由于这两种形式的癌症通常在患者开始表现出疾病症状之前未被发现，而这些症状通常与疾病的晚期有关。我建议确定和表征新的血液标志物，可用于开发筛选试验，用于胰腺癌和肝癌的早期检测，在癌组织对治疗性治疗反应最敏感的阶段。第2页在表格第2页的底部连续编号

DESCRIPTION (provided by applicant): Altered patterns of protein glycosylation and increased levels of serum proteins are often hallmarks of human diseases. Elevated serum levels of the glycoprotein gamma-glutamyl transpeptidase (GGT) are commonly seen in patients with tumors of the liver and pancreas and in patients with non malignant forms of liver and pancreatic diseases. An accumulating body of data indicates that GGT possesses tissue-specific and tumor-specific glycoforms that could be used to distinguish patients with cancer from those with other pathologies. My study will focus on the identification and characterization of tissue- and tumor-specific glycans on GGT. This study has three specific aims, which incorporate the use of state-of-the-art fluorescent HPLC and mass spectrometric techniques for glycoanalyses. The first specific aim is to identify tissue-specific glycoforms on GGT isolated from normal pancreas and liver tissue. The second specific aim is to identify tumor-specific glycan species on GGT isolated from tumors of the pancreas and liver and on GGT shed into the serum of patients with these malignancies. The third specific aim of this proposal is to develop antibodies against tissue- and tumor-specific glycoepitopes on GGT and to evaluate the sensitivity and specificity of these antibodies for detecting tissue- and tumor-specific GGT species in sera derived from non-diseased individuals and patients diagnosed with pancreatic adenocarcinoma, hepatocellular carcinoma, and non-malignant diseases of the pancreas and liver. These studies will also provide insight into the mechanism by which GGT is released from cellular membranes into serum during tumorigenesis. The timely and accurate diagnosis of pancreatic or liver cancer is critical for maximizing the efficacy of therapeutic treatments. This work will establish a foundation for the development of a serum-based immunoassay for the early detection of these malignancies using glycoepitopes on GGT shed into the serum. Lay summary: Survival rates for patients diagnosed with either pancreatic or liver cancer are very low. This is largely due to the fact that these two forms of cancer typically go undetected until patients begin showing disease symptoms, which are most often associated with advanced stages of the disease. I propose to identify and characterize novel blood markers that can be used to develop screening tests for the early detection of pancreatic and liver cancer at a stage when the cancerous tissues are the most responsive to therapeutic treatments. Page 2 Number pages consecutively at the bottom throughout Form Page 2