[Long-term cultures of experimental CNS tumours as models in neurooncological research (author's transl)].

Experiences with the behaviour of long-term cultures of experimental CNS tumours of rats induced by methylnitosourea of ethylnitrosourea, resp., are reported. Differences in cell kinetic parameters result in a selection of the best adapted cell type among those ones existing in the primary tumour. In some long-term cultures of gliomas and neurinomas an increasing polymorphism is observed by which these lines gain the morphological appearance of a glioblastoma multiforme. The loss of cell-specific morphological differentiations is a further type of anaplastic changes. In neuroectodermal tumour strains these alterations are temporarily reversible by means of addition of dibutyryl cyclic AMP to the culture fluid. There is no relationship between the type of tumour and the degree of anaplastic changes in vitro. Some cell strains remain constant for years and retain their specific properties. Their application as tester strains in neurooncological studies is recommended.