Takahashi Shiro, Sugiyama Taiki, Shimomura Mayuka, Kamada Yoshihiro, Fujita Kazutoshi, Nonomura Norio, Miyoshi Eiji, Nakano Miyako
Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, 739-8530, Japan.
Department of Molecular Biochemistry & Clinical Investigation, Osaka University Graduate School of Medicine, Osaka, Japan.
Glycoconj J. 2016 Jun;33(3):471-82. doi: 10.1007/s10719-016-9653-7. Epub 2016 Feb 11.
Fucosylation is an important type of glycosylation involved in cancer, and fucosylated proteins could be employed as cancer biomarkers. Previously, we reported that fucosylated N-glycans on haptoglobin in the sera of patients with pancreatic cancer were increased by lectin-ELISA and mass spectrometry analyses. However, an increase in fucosylated haptoglobin has been reported in various types of cancer. To ascertain if characteristic fucosylation is observed in each cancer type, we undertook site-specific analyses of N-glycans on haptoglobin in the sera of patients with five types of operable gastroenterological cancer (esophageal, gastric, colon, gallbladder, pancreatic), a non-gastroenterological cancer (prostate cancer) and normal controls using ODS column LC-ESI MS. Haptoglobin has four potential glycosylation sites (Asn184, Asn207, Asn211, Asn241). In all cancer samples, monofucosylated N-glycans were significantly increased at all glycosylation sites. Moreover, difucosylated N-glycans were detected at Asn 184, Asn207 and Asn241 only in cancer samples. Remarkable differences in N-glycan structure among cancer types were not observed. We next analyzed N-glycan alditols released from haptoglobin using graphitized carbon column LC-ESI MS to identify the linkage of fucosylation. Lewis-type and core-type fucosylated N-glycans were increased in gastroenterological cancer samples, but only core-type fucosylated N-glycan was relatively increased in prostate cancer samples. In metastatic prostate cancer, Lewis-type fucosylated N-glycan was also increased. These data suggest that the original tissue/cell producing fucosylated haptoglobin is different in each cancer type and linkage of fucosylation might be a clue of primary lesion, thereby enabling a differential diagnosis between gastroenterological cancers and non-gastroenterological cancers.
岩藻糖基化是一种与癌症相关的重要糖基化类型，岩藻糖基化蛋白可用作癌症生物标志物。此前，我们通过凝集素 - ELISA和质谱分析报告称，胰腺癌患者血清中触珠蛋白上的岩藻糖基化N - 聚糖增加。然而，已有报道称在各种类型的癌症中岩藻糖基化触珠蛋白均增加。为确定每种癌症类型中是否存在特征性岩藻糖基化，我们使用ODS柱LC - ESI MS对五种可手术的胃肠癌（食管癌、胃癌、结肠癌、胆囊癌、胰腺癌）、一种非胃肠癌（前列腺癌）患者血清中的触珠蛋白N - 聚糖进行了位点特异性分析，并与正常对照进行了比较。触珠蛋白有四个潜在的糖基化位点（Asn184、Asn207、Asn211、Asn241）。在所有癌症样本中，所有糖基化位点的单岩藻糖基化N - 聚糖均显著增加。此外，仅在癌症样本中检测到Asn 184、Asn207和Asn241位点的二岩藻糖基化N - 聚糖。未观察到癌症类型之间N - 聚糖结构的显著差异。接下来，我们使用石墨化碳柱LC - ESI MS分析从触珠蛋白释放的N - 聚糖糖醇，以确定岩藻糖基化的连接方式。胃肠癌样本中Lewis型和核心型岩藻糖基化N - 聚糖增加，但前列腺癌样本中仅核心型岩藻糖基化N - 聚糖相对增加。在转移性前列腺癌中，Lewis型岩藻糖基化N - 聚糖也增加。这些数据表明，产生岩藻糖基化触珠蛋白的原始组织/细胞在每种癌症类型中是不同的，岩藻糖基化的连接方式可能是原发性病变的线索，从而能够对胃肠癌和非胃肠癌进行鉴别诊断。
