缺氧微环境对胶质瘤细胞U251迁移性的影响

目的：探讨二氯化钴模拟化学缺氧的细胞微环境对人胶质瘤U251细胞增殖与迁移性的影响及其机制。方法胶质瘤U251细胞的培养基中加入二氯化钴模拟细胞缺氧，通过MTS检测细胞增殖，通过划痕实验检测细胞迁移，通过实时荧光定量PCR检测U251细胞表达血管内皮生长因子水平，采用免疫印迹检测细胞内缺氧诱导因子HIF-1α、动力蛋白RhoA与Cdc42、粘附分子E-cadherin与β-catenin表达，以及该过程中信号转导因子STAT3的磷酸化水平。结果二氯化钴不会促进U251细胞增殖，能显著促进细胞迁移；缺氧条件下U251细胞内VEGF水平升高， E-cadherin、β-catenin表达降低， HIF-1α表达和STAT3磷酸化水平随时间上调。结论二氯化钴模拟缺氧微环境可通过抑制U251细胞间粘附分子E-cadherin、β-catenin表达和提高VEGF-a水平，促进胶质瘤细胞迁移及周围血管生成，增强胶质瘤迁移与转移能力，细胞内信号转导分子HIF-1α和STAT3的激活在该过程中起重要作用。

Effect of Hypoxic Microenvironment on the Invasiveness of U251 Hu-man Glioma Cells

Objective To investigate the effect of cobalt chloride-induced hypoxia microenvi-ronment on the proliferation and invasiveness of U251 human glioma cells and the underlying mecha-nism. Methods Cobalt chloride was added to the culture medium to induce hypoxia microenviron-ment. Cell proliferation was tested by MTS method, cell migration by wound healing assay, and the level of vascular endothelial growth factor ( VEGF) produced by U251 cells by real-time quantitative PCR. The expression of hypoxia-inducible factor HIF-1α, cell motion-related molecules RhoA and Cdc42, cell adhesion-related molecules E-cadherin and β-catenin, and protein phosphorylation of STAT3 were measured by Western blotting. Results Hypoxia microenvironment couldn’t promote the proliferation of U251 cells, but significantly enhance the capacity of cell migration. Under the condition of hypoxia, the production of VEGF was increased, the expression of E-cadherin and β-catenin decreased and the level of HIF-1α and STAT3 phosphorylation enhanced with time in U251 cells. Conclusion Hypoxia microenvironment induced by cobalt chloride may enhance the invasive-ness of U251 human glioma cells by promoting glioma cells’ migration. The expression of hypoxia-inducible factor HIF-1α and the activation of intracellular signal transduction molecule STAT3 play important roles in the process.