Carbohydrate Antigenic Biomarkers for Epithelial Cancers

描述（由申请人提供）：拟议项目的主要重点是表征和随后应用人类流行上皮癌的潜在生物标志物：前列腺癌特异性碳水化合物抗原F77，以及乳腺癌更广泛表达的上皮癌相关碳水化合物抗原AE 3，两者均被单克隆抗体识别。该项目汇集了一个科学家团队，他们在碳水化合物，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以及独特且注释良好的临床标本方面具有非常互补的专业知识和技术能力。我们打算采用两种主要方法来表征F77和AE 3抗原的结构。第一种是碳水化合物微阵列分析与质谱联用，使用从前列腺癌细胞系PC-3和AE 3抗原阳性上皮粘蛋白产生的聚糖阵列。第二种是细胞转染特定的糖基转移酶和其他糖修饰酶，如磺基转移酶，这种方法最近取得了相当大的成功。一旦表征，F77和AE 3抗原性聚糖序列将作为关键探针包括在我们已经建立的碳水化合物微阵列平台中，该平台目前包括糖蛋白和糖脂的700多个聚糖序列。这将为分析癌症患者血清中F77和AE 3自身抗体以及任何其他聚糖生物标志物的存在以及设计用于检测异常糖抗原血症的新分析程序开辟道路;其中一种方法将是免疫蛋白质组学。F77和AE 3抗原的表达也将作为基于组织的预后标志物进行评估，以鉴定侵袭性原发性前列腺癌。最后，将研究F77抗原在癌细胞转移能力中的机制作用 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，现有的用于检测和表征的筛查方法在各种方面都不令人满意和不可靠。应用生物标志物检测前列腺癌和乳腺癌并提供关于个体患者预后的信息将是非常有用的，并为目前的低灵敏度和/或特异性筛选方法提供了非常理想的替代方案。 公共卫生相关性：这项研究旨在开发基于癌症特异性碳水化合物抗原的新型乳腺癌和前列腺癌组织或血清生物标志物。抗原的表征将导致抗体或抗原导向的测定，其可以改善这些常见癌症的诊断和/或预后。这将改善筛查策略，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措施，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，并使侵袭性疾病的治疗更早，更有效。

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.