组织蛋白酶D在星形细胞瘤中心区、周缘区和水肿区的表达情况

Expression of cathepsin D in the central, peripheral and edematous areas of human astrocytomas

目的探讨组织蛋白酶D（CathD）在人脑星形细胞瘤瘤体中心区、周缘区和瘤周水肿区的表达情况及临床意义。方法选择核磁共振检查未见肿瘤坏死或囊变且瘤体区与水肿区有明显分界的41例星形细胞瘤患者，分为复发组13例、未复发组28例。术中对照磁共振FLAIR序列留取瘤体中心区、周缘区和水肿区后行CathD免疫组化染色，对其在不同区域表达水平进行分析。结果CathD在正常脑组织无或弱表达，其在瘤体中心区、瘤周水肿区和周缘区呈阳性表达，且周缘区[（10．780±1．557）分]高于中心区[（2．610±0．945）分]，差异有统计学意义（P〈0．05）。在瘤体周缘区复发组CathD表达[（11．539±1．127）分]强于未复发组[（10．429±1．620）分]，差异有统计学意义（P〈0．05），而在瘤体中心区复发组与未复发组CathD表达差异无统计学意义（P〉0．05）。结论周缘区和水肿区CathD明显表达提示瘤周水肿区可能是瘤细胞易于发生浸润的区域；中心区CathD相对低表达说明该区细胞外基质已被降解殆尽，是肿瘤侵袭较早发生的区域；周缘区和水肿区CathD表达情况可作为一种判断肿瘤复发的指标。

Objective To study the expression ofcathepsin D （CathD） in the central, peripheral and edematous areas of human astrocytomas and its clinical implications. Methods Forty-one patients with astrocytomas showing clear boundaries between the tumor area and the edematous area but without tumor necrosis or cystic degeneration as shown by magnetic resonance imaging （MRI） were divided into recurrent group （13 patients） and non-recurrent group （28 patients）. Surgical specimens of the tissues in the central, peripheral and edematous areas of the tumor were obtained according to MR images using FLAIR sequence for detecting CathD expression with immunohistochemistry Results Normal brain tissues had virtually no or low CathD expression. Positive CathD expression was found in the central, peripheral and edematous areas of the astrocytomas, and the expression was significantly higher in the peripheral area （2.610±0.945） than in the central area （10.780±1.557） of the tumor （P〈0.05）. Patients in the recurrent group had more intense CathD expression in the peripheral area of the tumor than those in the non-recurrent group （11.539±1.127 vs 10.429±1.620, P〈0.05）, but in the central area of the tumor, the expression was comparable between the two groups （P〉0.05）. Conclusion Obvious CathD expression in the peripheral and edematous areas of the astrocytomas may suggest the likeliness of potential astrocytoma infiltration in these areas. The relative low CathD expression of CathD in the central area of the tumor indicates almost total degradation of the extracellular matrix as a result of early tumor invasion. CathD expression in the peripheral and edematous areas of the astrocytomas may serve as an indicator of tumor recurrence.