OBJECTIVE: Glioblastoma multiforme is a malignant primary brain tumor associated with short patient survival despite aggressive treatment, in part because of its propensity to aggressively infiltrate into brain tissue. Glioblastoma multiforme is also unique because it is the only nonepithelial human tumor for which excessive activation of epidermal growth factor receptor (EGFR) has been consistently linked to tumor growth and patient survival, and EGFR activation promotes glioblastoma multiforme infiltration in vitro.METHODS: Cocultures of human glioblastoma spheroids (derived from three separate patients) and fetal rat brain aggregates were examined for infiltration using confocal microscopy, in the presence of 0 to 100 mumol/L genistein, a tyrosine kinase (TK) inhibitor, and 3 mumol/L tyrphostin A25, a specific EGFR-TK inhibitor. RESULTS: Infiltration (not attachment) was completely inhibited by genistein at 10 mumol/L, the IC20 for monolayer growth inhibition in two cell lines. Tyrphostin A25 at 3 mumol/L (the IC20 for monolayers) reduced invasion in a third cell line from 38.8 +/- 6.1% invasion-hour per hour (n = 5) to 2.9 +/- 1.2% invasion-hour per hour (n = 6) (P = 0.0002, two-tailed t test, 93% inhibition), and from 0.54 +/- 0.065% per hour (slope) to 0.028 +/- 0.018% per hour (P = 0.00001, 95% inhibition). Maximal percent invasion was reduced from 100 +/- 0 to 7.4 +/- 5.6% of the fetal rat brain aggregate.nochange was detected in EGFR-associated tyrosine phosphorylation at those doses in monolayers by 32P immunolabeling, consistent with the known effects of low concentrations of TK inhibitors. An increase in expression of wild-type and truncated EGFR was demonstrated by Western blotting. Invasion was equally well inhibited by a monoclonal antibody to the high-affinity ligand binding domain of EGFR and not by antibody to an inactive domain. CONCLUSION: Our observations support the role of EGFR activation as a determinant by which glioblastoma invades normal brain tissue, and we show that invasion can be effectively inhibited at much lower concentrations of TK inhibitors than are necessary for growth suppression.

目的  多形性胶质母细胞瘤是一种原发性恶性脑肿瘤，患者尽管接受积极的治疗，生存期也比较短，部分是因为它倾向于侵略脑组织。多形性胶质母细胞瘤也是唯一一种人非上皮细胞癌症，它是由于表皮生长因子受体 (EGFR) 的过度激活导致肿瘤生长，这关乎病人存活，并且，EGFR激活促进多形性胶质母细胞瘤体外侵袭。 
方法  使用酪氨酸 （TK） 激酶抑制0 到 100微摩尔/升 金雀异黄素、和特定的EGFR-TK抑制剂3微摩尔/升酪氨酸磷酸化抑制剂 A25，以共焦显微镜检查验讫人胶质母细胞瘤球状体细胞（来源于三个不同的的病人）和胎鼠脑聚合物共培养渗透。 
结果  渗透 （而不是吸附） 完全被10微摩尔/升的金雀异黄素抑制，这为两个细胞系中的单层生长抑制作用的 IC20。3微摩尔/升酪氨酸磷酸化抑制剂A25（为单分子膜的 IC20) 减少第三的细胞系侵袭从38.8 +/- 6.1% 侵袭-时间/每小时 (n = 5) 到 2.9 +/- 1.2%侵袭-时间/每小时(n = 6) (P = 0.0002, 正反测验t 试验, 93% 抑制率), 及 从 0.54 +/- 0.065% /每小时(斜率) 到 0.028 +/- 0.018% /每小时(P = 0.00001, 95% 抑制率).。胎鼠脑聚合物的最大侵袭百分比从100 + /-0减少到7.4 + /-5.6 %。表皮生长因子相关酪氨酸磷酸化在这些剂量单分子膜中符合已知的 TK 抑制剂的低浓度影响，32P 免疫标记没有检测到更改。蛋白质印迹法表明野生型和截断表皮生长因子的表达增加。表皮生长因子高亲和配体结合域单克隆抗体，而不是到一个处于非活动状态的域的抗体抑制侵袭。