Tumorigenicity of cell lines (VMDk) derived from a spontaneous murine astrocytoma. Histology, fine structure and immunocytochemistry of tumours.

Three cell lines (VMDk), derived from a spontaneous murine astrocytoma, which exhibit both morphological and antigenic characteristics of astrocytes in vitro (Pilkington et al. 1983), have been injected intracerebrally and subcutaneously into syngeneic mice at a range of concentrations in order to assess the number of cells required to produce the highest yield of tumours with the shortest possible latent period. Light- and electron-microscopical studies of the tumours confirmed their glial nature, however immunocytochemical staining for the astrocyte-specific markers glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) and for vimentin suggest that the tumours are composed mainly of poorly-differentiated neoplastic glial cells. Although the best-differentiated of the three cell lines failed to produce tumours, an invasive transplantable astrocytoma model has, nevertheless, been characterised fully and can now be used to study the effects of various therapeutic regimens.