Bruyneel E A, Debray H, De Mets M, Mareel M M, Montreuil J
Department of Radiotherapy and Nuclear Medicine, University Hospital, Ghent, Belgium.
Clin Exp Metastasis. 1990 May-Jun;8(3):241-53. doi: 10.1007/BF00141255.
The changes in glycosylation of an immortalized epithelial cell line (MDCK) before and after progression towards a more malignant phenotype have been studied. The parental MDCK-3 cells were immortalized after long-term passage in vitro and have shown no tendency for spontaneous acquisition of malignancy-related phenotypes such as tumorigenicity, invasion and metastasis. They conserved morphological and functional characteristics of the epithelial tissue of origin. The ras-MDCK cells acquired the fully malignant phenotype after transformation with a Harvey murine sarcoma virus; they were immortalized, invasive in vitro and produced invasive and also metastatic tumors after subcutaneous injection into nude mice. Using immobilized lectins and gel chromatography, before and after liberation of O-linked glycans from the peptide moieties and also after removal of terminal sialic acid, we have found differences in the glycosylpeptides of both whole cells and cell surface trypsinates from ras-MDCK cultures as compared to the parental MDCK-3 cultures: (i) more sialic acid in the N-linked tri- and tetra-antennary structures; (ii) more fucosylation in the N-glycosylpeptides; (iii) more bi-antennary N-glycosylpeptides and less O-linked glycans; and (iv) a lower molecular weight of the O-linked glycans probably due to a decreased sialylation. It is concluded that alterations in sialylation and fucosylation of the cell surface exposed glycans accompanied progression of MDCK-3 cells towards a more malignant phenotype.
已对一种永生化上皮细胞系（MDCK）在向更恶性表型进展前后的糖基化变化进行了研究。亲代MDCK - 3细胞在体外长期传代后永生化，且未表现出自发获得与恶性相关表型（如致瘤性、侵袭和转移）的倾向。它们保留了起源上皮组织的形态和功能特征。ras - MDCK细胞在用哈维鼠肉瘤病毒转化后获得了完全恶性表型；它们是永生化的，在体外具有侵袭性，皮下注射到裸鼠体内后会产生侵袭性和转移性肿瘤。使用固定化凝集素和凝胶色谱法，在从肽部分释放O - 连接聚糖后以及去除末端唾液酸后，我们发现与亲代MDCK - 3培养物相比，来自ras - MDCK培养物的全细胞和细胞表面胰蛋白酶消化物的糖基肽存在差异：（i）N - 连接的三触角和四触角结构中唾液酸更多；（ii）N - 糖基肽中岩藻糖基化更多；（iii）双触角N - 糖基肽更多且O - 连接聚糖更少；以及（iv）O - 连接聚糖的分子量可能由于唾液酸化减少而降低。结论是，细胞表面暴露聚糖的唾液酸化和岩藻糖基化改变伴随着MDCK - 3细胞向更恶性表型的进展。
