Medulloblastoma displays distinct regional matrix metalloprotease expression

Matrix metalloproteases (MMPs) play an important role in tissue remodeling and neoangiogenesis during tumor progression. Little is known about the pre sence and regional distribution of MMPs in medulloblastomas. Based on immun ohistochemical, immunocytochemical and zymographical analysis the present s tudy illustrates the differential pattern of MMP expression for the medullo blastoma compared to that of glioma and ependymoma. In 10 examined medullob lastoma tumors gelatinase-A was strongly expressed by clusters of tumor cel ls. Gelatinase-B was, similar to glioma and ependymoma, predominantly found around endothelial cells. The DAB signal for macrophage metalloelastase wa s seen around macrophages and matrilysin was expressed by single tumor cell s. Stromelysin-1 protein was detected in medulloblastoma but not in glioma or ependymoma. From the presented data it follows that each tumor entity mi ght display its own characteristic MMP expression pattern.