胶质瘤MRI特征与血管内皮生长因子表达的相关性

目的　研究血管内皮生长因子 (VEGF)表达与人脑胶质瘤MRI表现的关系 ,探讨胶质瘤影像学表现的分子机制 .方法　采用免疫组织化学技术从蛋白质水平检测 2 2例人脑胶质瘤和 3例正常脑组织的VEGF表达 ;术前均行MRI检查 ,T2加权像测定瘤周脑水肿大小 ,并与瘤体体积相比较计算水肿指数 ;静脉注射钆 喷替葡甲胺 (Gd DTPA)后T1加权像观察肿瘤增强情况 .结果　 2 2例胶质瘤中 ,2 0例表达VEGF ,I级胶质瘤有 2例未表达 .VEGF表达水平与瘤周脑水肿系数呈显著正相关 (r=0 .811,P <0 .0 1) .注射Gd DTPA后 19例均呈不同程度强化 ,免疫组化染色显示均表达VEGF ;3例低恶度 (WHOI Ⅱ级 )胶质瘤无强化 ,其中 2例I级胶质瘤及正常脑组织既无VEGF表达也无强化 .结论　颅内胶质瘤VEGF表达与瘤周脑水肿及肿瘤强化呈正相关 .VEGF表达与胶质瘤MRI特征的相关性研究 ,可为阐明胶质瘤影像学表现的分子机制及临床评价和治疗胶质瘤提供有价值信息 .

Expression of vascular endothelial growth factor in human glioma specimens: Correlation with MRI findings

AIM To determine whether the expression of vascular endothelial growth factor (VEGF) is correlated with MR findings of human glioma, and to explore the molecular basis of various MR findings of glial tumors. METHODS 22 glioma specimens and 3 normal brain tissues were selected for retrospective analysis. VEGF protein was confirmed in tissue section by immunohistochemical techniques. Preoperative MRI was used to measure the peritumoral vasogenic brain edema (PVBE) and to determine the presence of tumor enhancement. RESULTS Of the 22 glioma specimens, 20 immunostained positively for VEGFand 2 low grade specimens failed to stain for VEGF. Edema index was positively correlated ( P <0.01) with the level of VEFG expression. 19 lesions enhanced by contrast injection immunostained positively for VEGF, while 2 low grade gliomas and 3 normal brain tissues did not exhibit either contrast enhancement or VEGF expression. CONCLUSION In gliomas, there was a significant correlation between VEGF levels and MR findings, such as PVBE and tumor contrast enhancement. VEGF may play a pivotal role in both the occurrence of PVBE and the presence of contrast enhancement in gliomas. The overexpression of VEGF provides a useful parameter in understanding the molecular basis of various MR findings of gliomas and in selecting the target gene for gene therapy.