Localization of gelatinase activities in glioma tissues by film in situ zymography.

Malignant gliomas are characterized by their invasiveness and angiogenesis, which are mediated by metalloproteinases (MMPs). In this study, localization of gelatinase activities in six cases of glioblastoma, two cases of anaplastic astrocytoma, and six cases of low-grade astrocytomas was investigated by film in situ zymography (FIZ). FIZ is a novel technique, because it allows preservation of tissue structure with gelatinolytic activity and can detect net MMP activity in tumor tissues. In malignant gliomas, gelatinolytic activities were extensively localized in the vessel walls in the viable tumor areas and peritumoral areas as well as the tumor cell itself. These findings suggest that FIZ is a useful tool not only to detect tumor net MMP activities but also to detect angiogenic features in the invading front of malignant gliomas.