Neu5Gc and anti-Neu5Gc antibodies for detection of cancer and cancer risk

描述(申请人提供)：多年前的研究表明，细胞表面唾液酸N-羟基神经氨酸(NeuSGc)是人类的一种“肿瘤胎儿抗原”，癌症患者表达针对它的抗体。我们的应用程序使用现代血糖和高通量方法重新研究了这个问题，并根据一个新的范式：人类在合成NeuSGc方面存在遗传缺陷，并且可以通过代谢将其整合到某些饮食来源(特别是红肉和牛奶)的肿瘤中。此外，初步证据表明，多克隆人抗Neu5Gc抗体反应检测到包含NeuSGc的广泛且高度可变的表位谱。因此，我们建议研究NeuSGc、含NeuSGc的糖链对分泌糖偶联物和特异性抗NeuSGc抗体的总体身体负荷，作为肺癌、胰腺癌和卵巢癌早期检测的生物标志物。为了实现我们的目标，我们组建了一支由糖生物学家、化学家、肿瘤学家和生物统计学家组成的专家团队，以及糖组学和通过微阵列进行抗体筛查的专家。利用各种已建立的和新开发的方法，我们建议获得关于原发人类肿瘤以及早期和晚期肿瘤患者的血清和尿样中NeuSGc-葡聚糖表达的性质和结构复杂性的基线信息。同时，我们正在开发一种灵敏而特异的方法来确定NeuSGc的总身体负荷。为了确定抗体反应，我们将合成/获得含有α-连接的NeuSGc或NeuSAc的匹配的糖链，并将验证和优化利用这些靶点的新的糖链阵列。将优化多糖的合成和结合，确定阵列底物和杂交条件，并定义试剂间和受试者间的可变性。其目标是通过比较癌症病例和对照来识别癌症特异性抗NeuSGc抗体模式。灵敏度和特异度的初步近似将在预定义的中期分析中做出，并决定扩大或缩小癌症类型的检测范围。这种方法产生的数据也将被用来确定糖链阵列的额外迭代的需要。最后，我们将使用全身NeuSGc负荷和/或特定的NeuSGc-多糖和/或抗NeuSGc抗体模式的组合，来识别患有癌症和不患有癌症的患者之间的癌症特异性差异，用于早期诊断和预后。

DESCRIPTION (provided by applicant): Studies from many years ago suggested that the cell surface sialic acid N-glycolylneuraminic Acid (NeuSGc) is an "oncofetal antigen" in humans, and that patients with cancer express antibodies against it. Our application revisits this matter using modern glycomic and high-throughput approaches, and in the light of a new paradigm: that humans are genetically defective in synthesizing NeuSGc and can metabolically incorporate it into tumors from certain dietary sources (particularly red meat and milk). Furthermore, preliminary evidence indicates that the polyclonal human anti-Neu5Gc antibody response detects a wide and highly variable spectrum of NeuSGc-containing epitopes. We therefore propose to study total body burden of NeuSGc, NeuSGc-containing glycans on secreted glyconjugates and specific anti-NeuSGc-antibodies-as biomarkers for the early detection of carcinomas of the lung, pancreas and ovary. To achieve our goals, we have assembled an expert team of glycobiologists, chemists, oncologists and biostaticians, along with specialists on glycomics and on antibody-screening by microarrays. Using various established and newly developed approaches we propose to obtain baseline information on the nature and structural complexity of NeuSGc-glycan expression in primary human tumors, and in serum and urine samples from subjects with early and late-stage tumors. In parallel, we are developing a sensitive and specific method to determine the total body burden of NeuSGc. In order to define the antibody response, we will synthesize/obtain matched sets of glycans containing alpha-linked-NeuSGc or NeuSAc, and will validate and optimize a novel glycan array utilizing these targets. Glycan synthesis and conjugation will be optimized, array substrate and hybridization conditions determined, and inter-assay and inter-subject variability defined. The goal is to identify cancer-specific anti-NeuSGc antibody patterns by comparing cancer cases and controls. Initial approximations of sensitivity and specificity will be made at predefined interim analyses with decisions to expand or narrow testing of cancer types. The emerging data from this approach will be also used to define the need for additional iterations of the glycan array. Finally, we will use combinations of total body NeuSGc burden and/or specific NeuSGc-glycans and/or anti-NeuSGc antibody patterns, to identify cancer-specific differences between ill subjects with and without cancer, for use in early diagnosis and prognosis.