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

Abstract

Objective To study the expression of cathepsin 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). 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. Key words: Astrocytomns; Central area of the tumor; Peripheral area; Edematous area; Cathepsin D