Carbohydrate Antigenic Biomarkers for Epithelial Cancers

描述（由申请人提供）：拟制项目的主要重点是人类常见上皮性癌症的潜在生物标志物的表征和后续应用：前列腺癌特异性碳水化合物抗原F77和乳腺癌，更广泛表达的上皮性癌症相关碳水化合物抗原AE3，两者都被单克隆抗体识别。该项目汇集了一组科学家，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巨大的专业知识和技术能力。我们打算采用两种主要方法对F77和AE3抗原进行结构表征。第一种是碳水化合物微阵列分析，结合质谱分析，使用从前列腺癌细胞系PC-3和AE3抗原阳性上皮粘蛋白中产生的聚糖阵列。第二种方法是细胞转染特异性糖基转移酶和其他糖修饰酶，如硫基转移酶，这种方法最近取得了相当大的成功。一旦鉴定，F77和AE3抗原聚糖序列将作为关键探针纳入我们已经建立的碳水化合物微阵列平台，该平台目前包括700多个糖蛋白和糖脂的聚糖序列。这将为分析癌症患者血清中F77和AE3的自身抗体以及任何其他聚糖生物标志物的存在开辟道路，并为检测异常糖抗原血症设计新的分析程序；其中一种方法是免疫蛋白质组学。F77和AE3抗原的表达也将被评估为基于组织的预后标志物，以识别侵袭性原发性前列腺癌。最后，我们将研究F77抗原在癌细胞转移能力中的机制作用

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.