Galectin-1 is highly expressed in human gliomas with relevance for modulation of invasion of tumor astrocytes into the brain parenchyma

Protein (lectin)-carbohydrate interaction is supposed to be relevant for tu mor cell behavior. The aims of the present work are to investigate whether galectin-1 modulates migration/invasion features in human gliomas in vitro, whether it can be detected in human gliomas immunohistochemically, and whe ther its expression is attributable to certain glioma subgroups with respec t to invasion and prognosis. For this purpose, we quantitatively determined (by computer-assisted microscopy) the immunohistochemical expression of ga lectin-1 in 220 gliomas, including 151 astrocytic, 38 oligodendroglial, and 31 ependymal tumors obtained from surgical resection, We also xenografted three human glioblastoma cell lines (the 1-14, U87, and U373 models) into t he brains of nude mice in order to characterize the in vivo galectin-1 expr ession pattern in relation to tumor invasion of the normal brain parenchyma . In addition, we characterized the role in vitro of galectin-1 in U373 tum or astrocyte migration and kinetics. Our data reveal expression of galectin -1 in all human glioma types with no striking differences between astrocyti c, oligodendroglial, and ependymal tumors. The level of galectin-1 expressi on correlated with the grade in the group of astrocytic tumors only. Furthe rmore, immunopositivity of high-grade astrocytic tumors from patients with short-term survival periods was stronger than that of tumors from patients with long-term survivals. In human glioblastoma xenografts, galectin-1 was preferentially expressed in the more invasive parts of these xenografts. In vitro experiments revealed that galectin-1 stimulates migration of U373 as trocytes. (C) 2001 Wiley-Liss, Inc.