HYALURONAN AND HYALURONECTIN IN THE EXTRACELLULAR-MATRIX OF HUMAN BRAIN-TUMOR STROMA

Hyaluronan (HA) and the hyaluronan-binding glycoprotein hyaluronectin (HN) were measured in 23 gliomas and 8 meningiomas and their location was revisited in 35 tumours. A clear-cut difference was found in the H N/HA ratio values of glioblastomas (below 0.5) and that of astrocytoma s (above 0.5 P < 0.001). Besides their location in the intercellular p art of gliomas, HA and HN displayed a perivascular location in 1/3 ast rocytomas, 17/24 glioblastomas, and 3/7 meningiomas, suggesting they c ould be produced also by the vascular stroma of tumours and that they would characterise the neoangiogenesis. All cultivated glioma cells te sted produced HA in vitro, whereas only 1/11 cell lines produced HN, a t a low level. The results obtained suggest that glioma HA and HN are produced by both cancer cells and vascular stroma cells, which contrib ute to the edification of the extracellular matrix. In meningiomas onl y the stroma would be responsible for HA and HN production.