Carbohydrate Antigenic Biomarkers for Epithelial Cancers

描述(由申请人提供)：拟议项目的主要重点是人类常见上皮癌潜在生物标记物的表征和随后的应用：前列腺癌特异性碳水化合物抗原F77，对于乳腺癌，更广泛表达的上皮癌相关碳水化合物抗原AE3，两者都被单抗识别。该项目汇集了一组在碳水化合物、免疫生物学、癌细胞生物学、肿瘤学、蛋白质组学和计算生物学方面具有巨大互补专业知识和技术能力的科学家团队，以及独特和注释良好的临床标本。我们打算采用两种主要方法来表征F77和AE3抗原的结构。第一种是利用前列腺癌细胞系PC-3和AE3抗原阳性的上皮粘蛋白产生的糖链阵列结合质谱仪进行碳水化合物微阵列分析。第二种是特定糖基转移酶和其他糖修饰酶(如磺基转移酶)的细胞转染法，这一方法最近取得了相当大的成功。一旦确定，F77和AE3抗原性多糖序列将作为关键探针被包括在我们已经建立的碳水化合物微阵列平台中，该平台目前包括700多个糖蛋白和糖脂的多糖序列。这将为分析癌症患者血清中是否存在F77和AE3以及任何其他糖链生物标志物的自身抗体以及为检测异常糖抗原血症设计新的分析程序开辟了道路；免疫蛋白质组学将是一种这样的方法。F77和AE3抗原的表达也将被评估为基于组织的预后标志，以识别侵袭性的原发性前列腺癌。最后，我们将研究F77抗原在癌细胞转移能力中的作用机制。 将生物标志物的存在与肿瘤的生物学联系起来。对于前列腺癌和乳腺癌，现有的检测和表征筛查方法都不令人满意和不可靠。应用生物标记物检测前列腺癌和乳腺癌，并提供有关个体患者预后的信息，将是非常有用的，并提供了一种非常理想的替代目前低敏感性和/或特异性筛查方法。 公共卫生相关性：这项研究旨在开发基于组织或血清的新型乳腺癌和前列腺癌生物标志物，其基础是癌症特异性碳水化合物抗原。对这些抗原的表征将导致抗体或抗原导向的分析，从而改善这些常见癌症的诊断和/或预后。这将改进筛查战略，以更好地区分良性和恶性疾病，减少不必要的活检或其他干预，并为治疗决策提供信息，以减少对非侵袭性疾病的过度治疗，并使侵袭性疾病能够更早和更有效地治疗。

DESCRIPTION (provided by applicant): The major focus of the proposed project is the characterization and subsequent application of potential biomarkers of prevalent epithelial cancers in humans: the prostate cancer-specific carbohydrate antigen, F77, and for breast cancer, the more broadly-expressed epithelial cancer-associated carbohydrate antigen, AE3, both recognized by monoclonal antibodies. The project brings together a team of scientists with hugely complementary expertise and technical capabilities in carbohydrates, immunobiology, cancer cell biology, oncology, proteomics, and computational biology, as well as unique and well-annotated clinical specimens. We intend to adopt two main approaches to the structural characterization of F77 and AE3 antigens. The first is carbohydrate microarray analysis coupled with mass spectrometry using glycan arrays generated from the prostate cancer cell line, PC-3, and from AE3 antigen-positive epithelial mucins. The second is cell transfection of specific glycosyltransferases and other glyco-modifying enzymes such as sulfotransferases, an approach that has recently met with considerable success. Once characterized, the F77 and AE3 antigenic glycan sequences will be included as key probes in a carbohydrate microarray platform that we have established that presently includes more than 700 glycan sequences of glycoproteins and glycolipids. This will open the way to analysis of cancer patient sera for the presence of autoantibodies to F77 and AE3 and any other glycan biomarkers and to the design of new analysis procedures for the detection of aberrant glyco-antigenemia; one such approach will be by immune-proteomics. The expression of F77 and AE3 antigens will also be evaluated as tissue-based prognostic markers to identify aggressive primary prostate cancer. Finally, the mechanistic role of the F77 antigen in metastatic capabilities of cancer cells will be investigated to link the presence of the biomarker to the biology of the tumor. For prostate and breast cancers, existing screening methods for detection and characterization are variously unsatisfactory and unreliable. The application of biomarkers to detect prostate and breast cancer and to provide information about the prognosis of individual patients would be extremely useful and provide a very desirable alternatives to the current low sensitivity and/or specificity screening methods. PUBLIC HEALTH RELEVANCE: This research aims to develop novel tissue- or serum-based biomarkers for breast and prostate cancer based on cancer-specific carbohydrate antigens. Characterization of the antigens will lead to antibody- or antigen-directed assays that can improve diagnosis and/or prognosis for these common cancers. This will improve screening strategies to better distinguish benign from malignant disease and decrease unnecessary biopsies or other interventions, and inform treatment decisions to diminish over-therapy of non-aggressive disease and enable earlier and more effective therapy of aggressive disease.