ROLE OF CD44 IN THE INVASIVENESS OF GLIOBLASTOMA-MULTIFORME AND THE NONINVASIVENESS OF MENINGIOMA - AN IMMUNOHISTOCHEMISTRY STUDY

CD44 is a polymorphic family of cell adhesion molecules that seems to be instrumental in the mechanism of tumor invasion and metastasis. Tum or cell expression of CD44, or lack thereof, may be one of the factors conditioning the highly disparate ability to penetrate the brain extr acellular matrix (ECM) exhibited by glioblastoma multiforme (GM) and c onventional meningioma. To assess the presence of CD44 in these two tu mor types we have immunohistochemically investigated the expression of CD44 standard form (CD44s) and the variant isoforms containing the do main encoded by variant exon 3 (CD44v3) and variant exon 6 (CD44v6) in paraffin-embedded tissue from 10 conventional meningiomas and 10 GMs. A CD44s-/CD44v-phenotype was discerned in the meningioma cases, where as GMs featured a CD44s+/CD44v- expression profile. Consequently, the growth patterns of meningioma and GM seem to be, at least in part, a r eflection of their CD44 expression status. Paucity of CD44 in meningio ma cells would render them unable to infiltrate the brain ECM, whereas CD44-rich glioma cells would successfully migrate through it. Convers ely, lack of CD44v expression would contribute to explain the lack of metastatic potential characterizing both conventional meningioma and G M. Copyright (C) 1995 by W.B. Saunders Company