Effects of syndecan-1 on the expression of syntenin and the migration of U251 glioma cells.

Glioma is the most frequently occuring primary brain tumor. Syndecan-1 (SDC1) expression is related to poor prognosis of numerous human malignancies including glioma. Syndecan binding protein (SDCBP) is an important partner for SDC1. The present study investigated whether SDC1 and SDCBP are expressed in glioma and their functions on glioma cell migration. An immunohistochemical assay revealed that SDC1 and SDCBP were expressed and were positively related to malignant level of glioma (SDC1, rs=0.576, P=0.001; SDCBP, rs=0.661, P<0.001). Moreover, the protein levels of SDC1 were positively correlated with those of SDCBP in glioma tissues (rs=0.628, P=0.001). In U251 glioma cells, protein levels of SDC1 and SDCBP were both upregulated in U251 cells with SDC1 overexpression, while downregulated with SDC1 knockdown. Transwell assay and scratch-wound healing assay showed that SDC1 overexpression significantly increased U251 cell migration, while SDC1 knockdown had the opposite effects. Rac1 activity, signal transducer and activator of transcription 3 (STAT3) phosphorylation, as well as expression of matrix metalloproteinase 2 (MMP2) and MMP9 was significantly increased by SDC1 overexpression, while was decreased by SDC1 knockdown. In conclusion, SDC1 overexpression upregulated SDCBP expression, and promoted glioma cell migration via Rac1 activation.

胶质瘤是最常见的原发性脑肿瘤。多配体聚糖-1（SDC1）的表达与包括胶质瘤在内的许多人类恶性肿瘤的不良预后相关。多配体聚糖结合蛋白（SDCBP）是SDC1的重要伙伴。本研究探讨了SDC1和SDCBP是否在胶质瘤中表达以及它们对胶质瘤细胞迁移的作用。免疫组化分析显示，SDC1和SDCBP有表达，且与胶质瘤的恶性程度呈正相关（SDC1，rs = 0.576，P = 0.001；SDCBP，rs = 0.661，P < 0.001）。此外，在胶质瘤组织中，SDC1的蛋白水平与SDCBP的蛋白水平呈正相关（rs = 0.628，P = 0.001）。在U251胶质瘤细胞中，SDC1过表达时，U251细胞中SDC1和SDCBP的蛋白水平均上调，而SDC1敲低时则下调。Transwell实验和划痕愈合实验表明，SDC1过表达显著增加U251细胞的迁移，而SDC1敲低则有相反的效果。SDC1过表达显著增加Rac1活性、信号转导和转录激活因子3（STAT3）的磷酸化以及基质金属蛋白酶2（MMP2）和MMP9的表达，而SDC1敲低则使其降低。总之，SDC1过表达上调SDCBP的表达，并通过激活Rac1促进胶质瘤细胞迁移。