Alliance of Glycobiologists for Detection of Cancer

癌症检测糖生物学家联盟

基本信息

批准号：
9142266
负责人：
RADOSLAV GOLDMAN
金额：
$ 50.53万
依托单位：
GEORGETOWN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-14 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9142266
关键词：
Biological Assay Biological Markers Blood Circulation Cancer Detection Cirrhosis Detection Development Disease Disease Management Disease Outcome Fractionation Glycopeptides Glycoproteins Goals Gold Haptoglobins Health Human Human Genome Incidence Informatics Liver Liver Cirrhosis Liver diseases Malignant Neoplasms Malignant neoplasm of liver Methods Minor Modification Monitor Mutation N-Glycosylation Site Patients Peptides Polysaccharides Premalignant Prevention Research Primary carcinoma of the liver cells Protein Glycosylation Proteins Proteome Proteomics Reaction Research Resources SHBG gene Sampling Scheme Screening for Hepatocellular Cancer Screening for cancer Serological Serum Site Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Staging United States Variant alpha-Fetoproteins base cancer biomarkers cancer prevention candidate marker carcinogenesis case control diagnostic accuracy glycoproteomics glycosylation improved mutant protein distribution repository validation studies

项目摘要

DESCRIPTION (provided by applicant): This proposal aims to detect hepatocellular carcinoma (HCC) at a treatable stage by non-invasive methods. To this end, we propose to quantify site specific glycoforms of liver secreted N-glycoproteins (LNP) associated with the progression of liver disease to HCC. We and others have shown that changes in protein glycosylation accompany the development of HCC. Major re-distribution of protein N-glycoforms occurs at the premalignant stage of liver cirrhosis but our latest studies show that specific glycoforms of a glycopeptide of haptoglobin increase exclusively in HCC. We demonstrate that these minor glycoforms of haptoglobin are detectable in serum and have the potential to improve detection of HCC compared to the serologic gold standard, alpha fetoprotein (AFP). This supports our hypothesis that minor site specific glycoforms of abundant liver secreted N-glycoproteins provide HCC specific marker candidates detectable in the circulation. We propose to complete identification of the HCC specific N-glycans; we have already evidence that the glycans are characterized by multiple fucosylations and increased branching. We propose to identify glycopeptides of additional proteins carrying these HCC specific N-glycan modifications by newly optimized mass spectrometric methods. This is done because haptoglobin is downregulated in a fraction of cirrhotics and other proteins may be needed for optimal detection. We expand our informatic analysis to classify all polymorphic and mutant human N- glycoproteins with newly created or abolished N-glycosylation sites. These protein variants are over- represented in the human genome, represent prime candidates for association with diseases, and we expect that they have direct impact on carcinogenesis. We believe that a publically available resource of these variant proteins will stimulate glycoproteomic cancer prevention research. The proposed examination of HCC specific N-glycoforms is feasible because we have already created a repository of samples of HCC patients and cirrhotic controls. This repository, and additional outstanding QC resources, is essential for the isolation of the HCC specific minor glycoforms of liver secreted N-glycoproteins; these glycoforms are not detectable in disease free subjects. By the end of the study, we will have quantified the selected site specific protein glycoforms by targeted LC-MS selective reaction monitoring (SRM) methods. These methods will quantify the HCC associated site specific glycopeptides in serum with an unprecedented accuracy. We do this because we believe that quantification of specific glycoforms of specific glycoprotein peptides offers the highest diagnostic accuracy. Defining clinically applicable cancer markers has potentially far-reaching consequences for disease management and patient health. Our study is expected to generate new hypotheses on the functional impact of protein glycosylation on the development of cancer and to stimulate an entirely new line of cancer prevention and detection research.

描述（由申请人提供）：该提案旨在通过非侵入性方法在可治疗的阶段检测肝细胞癌（HCC）。为此，我们建议量化与肝病向HCC的进展相关的肝脏分泌N-糖蛋白（LNP）的特定部位糖型。我们和其他人表明，蛋白质糖基化的变化伴随着HCC的发展。蛋白质N-糖型的重大重新分布发生在肝硬化的前阶段，但我们的最新研究表明，Haptoglobin的糖肽的特定糖型仅在HCC中仅增加。我们证明，与血清学金标准α胎蛋白（AFP）相比，这些小抗果蛋白的这些次要糖型可在血清中检测到HCC的检测。这支持了我们的假设，即丰富的肝脏分泌的N-糖蛋白的次要部位特异性糖型可在循环中检测到HCC特异性标记候选物。我们建议完成对HCC特异性N-聚糖的识别；我们已经有证据表明，聚糖的特征是多种岩藻糖基化和增加的分支。我们建议通过新优化的质谱法确定携带这些HCC特异性N-聚糖修饰的其他蛋白质的糖肽。之所以这样做，是因为触觉球蛋白在一小部分卷虫中被下调，并且可能需要其他蛋白质才能进行最佳检测。我们扩展了信息分析，以将新产生或废除的N-糖基化位点分类所有多态性和突变的人类N-糖蛋白。这些蛋白质变异体在人类基因组中代表了与疾病关联的主要候选者，我们希望它们对癌变有直接影响。我们认为，这些变体蛋白质的公开可用资源将刺激糖蛋白酶癌症预防研究。提出的对HCC特异性N-糖型的检查是可行的，因为我们已经创建了HCC患者和肝硬化对照样本的存储库。该存储库和其他出色的QC资源对于隔离肝脏分泌的N-糖蛋白的HCC特异性小糖型至关重要。这些糖剂在无疾病的受试者中无法检测到。在研究结束时，我们将通过靶向的LC-MS选择性反应监测（SRM）方法对所选位点特异性蛋白质糖型进行量化。这些方法将以前所未有的精度来量化血清中HCC相关位点特异性糖肽。之所以这样做，是因为我们相信对特定糖蛋白肽的特定糖型的量化具有最高的诊断准确性。定义临床适用的癌症标志物可能对疾病管理和患者健康产生深远的影响。我们的研究有望产生有关蛋白质糖基化对癌症发展的功能影响的新假设，并刺激全新的预防癌症预防和检测研究。