谷氨酸对胶质瘤细胞分泌MMP-2及侵袭性的影响

Glutamate promotes secretion of MMP-2 and enhances invasion of glioma cells

目的研究谷氨酸促进胶质瘤侵袭性的机制。方法体外常规培养胶质瘤细胞株U251，用100μmol/L谷氨酸处理24h后Transwell细胞侵袭试验检测侵袭性；处理2、4、8、12h后应用明胶酶谱实验分析细胞基质金属蛋白酶2（MMP-2）和基质金属蛋白酶9（MMP-9）的分泌；处理3、6、9h后应用Westernblotting实验检测基质金属蛋白酶诱导因子（EMMPRIN）蛋白的表达。结果Transwell细胞侵袭试验显示谷氨酸组穿膜细胞数（37．44±2.31）明显多于对照组穿膜细胞数（25．89±3．001，差异有统计学意义（P＜0．05）；明胶酶谱分析实验显示谷氨酸处理8、12h后U251细胞分泌MMP-2增加，较对照组差异有统计学意义伴0．05）；Westernblotting检测显示谷氨酸处理U251细胞3、6、9h后EMMPRIN蛋白的表达无变化，较对照组差异无统计学意义（P〉O．05）。结论谷氨酸可能通过促进胶质瘤细胞分泌MMP-2增强胶质瘤细胞的侵袭性。MMP-9和EMMPRlN未参与谷氨酸增强胶质瘤细胞侵袭性的过程。

Objective To investigate the mechanism of invasion of glioma evoked by glutamate. Methods Glioma cell line U251 was cultured in vitro; cell invasion of U251 was detected by Matrigel Transwell method 24 h after 100 μmol/L glutamate treatment; MMP-2 and MMP-9 secretions were detected by gelatin zymography assay 2, 4, 8 and 12 h afte glutamate treatment; the protein expression of extracellular matrix metalloproteinase inducer （EMMPRIN） was detected by Western blotting 3, 6 and 9 h after glutamate treatment. Results Matrigel Transwell method indicated that the cells crossing the cytomembrane of U251 in the glutamate treatment group （37.44±2.31） were significantly increased as compared with those in the control group （25.89±3.00, P〈0.05）; MMP-2 secretion in the glutamate treatment group 8 and 12 h afte glutamate treatment was obviously increased as compared with that in the control group （P〈0.05）; while Western blotting indicated that no significant differences on the EMMPR1N level were noted between time points of 3, 6 and 9 h after glutamate treatment. Conclusion Glutamate promotes the secretion of MMP-2 in glioma cell line U251 to enhance the invasion of glioma cells; MMP-9 and EMMPRIN are not involved in the process of glutamate promoting the invading of U251.