Glycoproteins and Glycan-Binding IgGs: Biomarkers for Cancer and Inflammatory Di

描述(申请人提供)：结构不同的葡聚糖在炎症和癌症进展中显示出出人意料的强大作用。糖链结合蛋白识别糖链与生理和疾病相关的细胞黏附或细胞信号传递有关。肿瘤组织分泌糖蛋白，可诱导自身抗体的产生。癌症中的糖蛋白多糖水平和结构与良性疾病或炎症性疾病中发现的不同。最近，通过从乳腺癌和经典型霍奇金淋巴瘤(CHL)患者中分离的免疫球蛋白(Ig)组分筛选微阵列糖链，发现了一些癌症特异性的糖链生物标志物。在这两项研究中，随后用更大样本量的直接ELISA验证了多糖生物标记物。这些研究表明，被免疫球蛋白识别的多糖是疾病特异性和可靠的生物标志物。前列腺特异性抗原(PSA)核心蛋白水平升高已被广泛用于前列腺癌的检测、分期和监测。然而，PSA水平有时不能区分癌症和良性或炎症性疾病。在最近的一项研究中，在250份来自无癌个体的血浆样本中，约有20份PSA水平高于4 ng/ml(假阳性)，可能是由于前列腺增生症或前列腺炎。此外，PSA水平在4-10 ng/ml之间的患者中，约75%的活检标本为肿瘤阴性。因此，我们建议确定前列腺癌生物标记物，以弥补PSA检测在特异性方面的不足。高通量技术(糖蛋白和葡聚糖微阵列)和依赖于糖链结构和免疫球蛋白或免疫球蛋白(两种与癌症相关的两种主要免疫球蛋白)的糖链结合特异性的分离技术相结合，显示了获得区分前列腺癌和前列腺增生症的分子特征的前景。在第一阶段，我们将(A)通过与26个候选糖蛋白生物标记物(例如糖基化PSA)的凝集素/抗体微阵列分析来鉴定前列腺癌特异的血浆糖蛋白(核心蛋白和葡聚糖)生物标记物，(B)使用从9个不同长度和疏水性的内部合成接头中选择的葡聚糖连接物来开发前列腺癌特异的70个葡聚糖微阵列，以及(C)通过糖链微阵列检测IgG或IgM的葡聚糖结合谱，以获得前列腺癌特异的生物标志物。单个或标志性前列腺癌生物标志物的糖蛋白或多糖Ig对将使用统计和生物信息学工具进行识别。对于PSA假阳性的血浆标本，将进一步研究这些生物标志物的特异性。在第二阶段，将在第一阶段研究的基础上生产用于广泛血浆和组织筛选的临床直接ELISA和葡聚糖亚阵列。前列腺癌风险和侵袭性增加的研究将与寡糖生物合成途径多态有关。在第一阶段和第二阶段开发的新概念和技术可用于利用各种生物液和组织对其他癌症或炎症性疾病的生物标记物进行一般搜索。识别由自身抗体识别的前列腺癌特异性糖链将导致基于糖链的治疗方法的发展。

DESCRIPTION (provided by applicant): Structurally varied glycans displayed unexpectedly strong efects on inflammation and cancer progression. Glycan recognition by glycan-binding proteins is involved with physiological and disease-related cell adhesion or cell signaling. Tumor tissues secrete glycoproteins, which induce autoantibody production. Glycoprotein glycan levels and structures in cancer differ from those found in benign or inflammatory diseases. Recently, a few cancer-specific glycan biomarkers were identified by screening microarrayed glycans with immunoglobulin (Ig) fractions isolated from breast cancer and classical Hodgkin's lymphoma (cHL) patients. For both studies, subsequent direct ELISAs with larger sample sizes verified the glycan biomarkers. These studies demonstrated that glycans recognized by Igs are disease-specific and reliable biomarkers. Increased prostate-specific antigen (PSA) coreprotein levels have been widely used to detect, stage and monitor prostate cancer. However, PSA level sometimes cannot distinguish cancer from benign or inflammatory diseases. In a recent study, ~20 out of 250 plasma samples from cancer-free individuals had PSA levels higher than 4 ng/ml (false PSA positives) probably due to BPH or prostatitis. Moreover, ~75% of biopsy samples of individuals with PSA levels between 4 - 10 ng/ml were tumor negative. Thus, we propose to identify prostate cancer biomarkers to compensate for shortcomings in specificity of the PSA test. Combination of high-throughput technologies (glycoprotein and glycan microarrays) and fractionation technologies dependent on glycan structures and glycan-binding specificity of the IgG or IgM (2 major Igs involved with cancer) show promise of obtaining molecular signatures to distinguish prostate cancer from BPH. During Phase I, we will (a) identify prostate cancer-specific plasma glycoprotein (coreprotein and glycan) biomarkers by lectin/antibody microarray analyses with 26 glycoprotein biomarker candidates, e.g., glycosylated PSA, (b) develop prostate cancer-specific 70 glycan microarrays using glycan linkers selected among 9 in-house synthesized linkers of various lengths and hydrophobicity and (c) detect glycan-binding profiles of IgGs or IgMs to obtain prostate cancer-specific biomakers by the glycan microarray. Single or signature prostate cancer biomarkers of glycoprotein or glycan Ig pair will be identified using Statistics and Bioinformatics tools. Specificity of the biomarkers will be further investigated wit the false PSA positive plasma samples. During Phase II, clinical direct ELISAs and glycan subarrays for extensive plasma and tissue screening will be produced based on the Phase I study. Increased prostate cancer risk and aggressiveness will be studied in relation to oligosacharide biosynthesis pathway polymorphisms. New concepts and technologies developed during Phases I and II can be applied for general searches of biomarkers for other cancers or inflammatory diseases with various biological fluids and tissues. Identification of prostate cancer- specific glycans recognized by autoantibodies will lead to development of glycan-based therapeutics.