Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Department of Biochemistry, Yonsei University, Seoul, Republic of Korea.
Proteomics. 2018 Jan;18(1). doi: 10.1002/pmic.201700302. Epub 2017 Dec 19.
Glioblastoma, also known as glioblastoma multiforme (GBM), is the most malignant type of brain cancer and has poor prognosis with a median survival of less than one year. While the structural changes of tumor cell surface carbohydrates are known to be associated with invasive behavior of tumor cells, the cell surface glycoproteins to differentiate the low- and high-grade glioma cells can be potential diagnostic markers and therapeutic targets for GBMs. In the present study, lectin arrays consisting of eight lectins were employed to explore cell surface carbohydrate expression patterns on low-grade oligodendroglioma cells (Hs683) and GBM cells (T98G). Griffonia simplicifolia I (GS I) was found to selectively bind to T98G cells and not to Hs683 cells. For identification of the glioblastoma-specific cell surface markers, the glycoproteins from each cell type were captured by a GS I lectin column and analyzed by LC-MS/MS. The identified proteins from the two cell types were quantified using label-free quantitative analysis based on spectral counting. Of cell surface glycoproteins showing significant increases in T98G cells, five proteins were selected for verification of both protein and glycosylation level changes using Western blot and GS I lectin-based immunosorbent assay.
胶质母细胞瘤，又称多形性胶质母细胞瘤（GBM），是最恶性的脑癌类型，预后不良，中位生存期不到一年。虽然已知肿瘤细胞表面碳水化合物的结构变化与肿瘤细胞的侵袭行为有关，但区分低级别和高级别神经胶质瘤细胞的细胞表面糖蛋白可以作为 GBM 的潜在诊断标志物和治疗靶点。在本研究中，使用由八种凝集素组成的凝集素阵列来探索低级别少突胶质细胞瘤细胞（Hs683）和胶质母细胞瘤细胞（T98G）表面的碳水化合物表达模式。发现相思豆凝集素 I（GS I）选择性地与 T98G 细胞结合，而不与 Hs683 细胞结合。为了鉴定胶质母细胞瘤特异性的细胞表面标志物，用 GS I 凝集素柱捕获每种细胞类型的糖蛋白，并通过 LC-MS/MS 进行分析。基于光谱计数的无标记定量分析对来自两种细胞类型的鉴定蛋白进行定量。在 T98G 细胞中显示明显增加的细胞表面糖蛋白中，选择了五个蛋白，使用 Western blot 和基于 GS I 凝集素的免疫吸附试验来验证蛋白和糖基化水平的变化。
