Identification of internally sialylated carbohydrate tumor marker candidates, including Sda/CAD antigens, by focused glycomic analyses utilizing the substrate specificity of neuraminidase
Identification of internally sialylated carbohydrate tumor marker candidates, including Sda/CAD antigens, by focused glycomic analyses utilizing the substrate specificity of neuraminidase
复制标题
DOI：
10.1093/glycob/cwy010
复制
发表时间：
2018-05
期刊：
影响因子：
4.3
通讯作者：
M. Tanaka‐Okamoto;K. Hanzawa;M. Mukai;Hidenori Takahashi;M. Ohue;Y. Miyamoto
中科院分区：
文献类型：
--
作者：
M. Tanaka‐Okamoto;K. Hanzawa;M. Mukai;Hidenori Takahashi;M. Ohue;Y. Miyamoto
在我们之前的研究中，通过集中糖组学分析鉴定了14种硫酸化碳水化合物肿瘤标志物候选物。在此，糖组学分析集中于内部唾液酸化聚糖以鉴定新的标记物候选物。通过用鼠伤寒沙门氏菌的α-神经氨酸酶消化从血清中制备的吡啶胺化聚糖，富集内部唾液酸化聚糖，该酶不会裂解与内部残留物连接的唾液酸，然后进行阴离子交换色谱。接下来，使用两种类型的高效液相色谱法构建内部唾液酸化O-聚糖谱，并在20名健康对照者和11名胃癌患者和9名胰腺癌患者之间进行比较。总共鉴定了17个标记候选物。使用酶消化、聚糖合成、2D图谱和质谱法精确分析了聚糖候选物的结构。在17个候选物中，1个是STn，另外16个包含10个核心1、1个核心2和5个核心3聚糖。各种结构包括α 2，6-唾液酸化还原末端GalNAc和α 2，6-唾液酸化1型N-乙酰乳糖胺。8名候选人具有Sda/CAD抗原。使用选定的反应监测测定法对所有40名受试者血清中这些候选聚糖的水平进行定量，发现至少1名或多名患者的水平升高。尽管每种候选聚糖的血清水平在患者之间存在差异，但具有相同骨架或决定簇的候选聚糖（如具有扩展的1型N-乙酰基-乳糖胺的核心3骨架和核心1结构）显示出相似的升高模式。这些结果表明，多种标志物的分析可能是诊断各种癌症的有效手段。
In our previous study, 14 sulfated carbohydrate tumor marker candidates were identified by focused glycomic analyses. Here, glycomic analyses focused on internally sialylated glycans to identify novel marker candidates. Internally sialylated glycans were enriched by digestion of pyridylaminated glycans prepared from sera with α-neuraminidase from Salmonella typhimurium, which did not cleave sialic acids linked to internal residues, followed by anion-exchange chromatography. Next, internally sialylated O-glycan profiles were constructed using two types of high performance liquid chromatography, which were compared between 20 healthy controls and 11 patients with gastric cancer and 9 patients with pancreatic cancer. In all, 17 marker candidates were identified. The structures of glycan candidates were precisely analyzed using enzymatic digestion, glycan synthesis, 2D mapping and mass spectrometry. Among 17 candidates, one was STn, and the other 16 comprised 10 core1, 1 core2 and 5 core3 glycans. The various structures included a α2,6-sialylated reducing terminal GalNAc and α2,6-sialylated type1 N-acetyl-lactosamine. Eight candidates possessed the Sda/CAD antigen. The levels of these candidate glycans in sera from all 40 subjects were quantified using a selected reaction monitoring assay and found to be elevated in at least one or more patients. Although the serum levels of each candidate glycan varied between patients, those candidates having the same backbone or determinant, such as core3 backbone and core1 structures with extended type1 N-acetyl-lactosamine, displayed similar patterns of elevation. These results suggest that analysis of multiple markers may be an effective means of diagnosing various cancers.