Differential binding of anti-CD44 on human gliomas in vitro.

Recent studies have shown that the membrane glycoprotein, CD44, is expressed on both normal and neoplastic astrocytes. Moreover, CD44 has been shown to recognise the receptor for hyaluronic acid (HA), an extracellular matrix protein thought to be involved in tumour invasion. The present study has established, by immunocytochemical staining, that CD44 is present on the majority of cells in long and short term cultures derived from astrocytic gliomas. In glioblastoma multiforme, medulloblastoma, ependymoma and dysembryoplastic neuroepithelial tumour, however, staining is either absent or restricted to isolated cells. This differential binding suggests that HA receptor expression may be related to (a) the cell cycle and (b) local invasiveness of brain tumours.