AN IMMUNOHISTOCHEMICAL STUDY OF TISSUE TRANSGLUTAMINASE IN GLIOMAS WITH REFERENCE TO THEIR CELL DYING PROCESSES

Tissue transglutaminase is a Ca2+-dependent enzyme that catalyzes the formation of protein cross-links by an acyl transfer reaction. Recent reports have suggested that tissue transglutaminase is induced by tumo r progression and apoptosis. In this study we immunohistochemically in vestigated a series of gliomas by using an antiserum against a dodecap eptide from the COOH-terminal of tissue transglutaminase. Among the gl iomas the presence of positive immunoreactivity tended to increase in malignant counterparts. It is also noteworthy to mention that glioblas toma cells surrounding the zonal necrosis in a palisade fashion were s trongly immunolabeled The degenerating products in tumor cells, such a s round granulated bodies, were primarily immunopositive, whereas Rose nthal fibers were negative. Dying cells through apoptosis in the metas tatic brain tumors could be easily recognized by the presence of tissu e transglutaminase. In conclusion, tissue transglutaminase may therefo re be valuable in the prognostic characterization of gliomas with resp ect to the detection of dying cells. However, the appearance of tissue transglutaminase-positive neoplastic cells tons not limited to apopto tic bodies but could also be detected in necrobiotic cell nests.