Cell lines (VMDk) derived from a spontaneous murine astrocytoma. Morphological and immunocytochemical...

Three cell lines (VMDk) derived from a spontaneous, murine astrocytoma, which produce tumours when injected either subcutaneously or intracranially into syngeneic mice, have been examined in vitro. Ultrastructurally, the cells show astrocytic features but each line differs in its degree of differentiation. Treatment with both dexamethasone and dibutyryl adenosine 3',5'-cyclic monophosphate (dbcAMP) increases intracytoplasmic differentiation and causes surface structural changes. The addition of dbcAMP also induces a statistically significant increase in the length and number of cell processes. All three cell lines express the astrocyte-specific markers, glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS), by indirect immunofluorescence, with two lines showing an increased propensity to stain for GFAP following dbcAMP treatment. The cell surface antigen fibronectin is also detected in all lines. Thus these VMDK cell lines exhibit both the morphological and antigenic characteristics of astrocytes and respond to dexamethasone and dbcAMP and may be used to provide a suitable in vivo-in vitro model system for the study of astrocytoma.