Immunocytochemical features of human cultured meningioma cells

Objectives: One objection to using cell cultures for studying the proliferation of tumours is the potential for phenotypic changes that may occur in vitro. Here, we compared the antigen pattern of cultured meningioma cells with that of the primary tumour. Methods: Cell cultures established from 9 intracranial meningiomas and deparaffinized sections of the resected tumours were analyzed for immunophenotyping with the following antibodies: Vimentin, Cytocheratin, EMA, S-100, Neuron-Specific Enolase, Synaptophisin, Factor VHI-related Antigen, CD31, CD34, CD45RB, CD68 and MAC387. Results: The cultured meningioma cells retained one main feature of the primary tumour, being positive both for mesenchymal antigens and for epithelial antigens. Interestingly, the cultured meningioma cells abundantly expressed the CD68 antigen at passage 1. The CD68 antigen, that is normally expressed by haematopoetic cells, was not detectable on meningioma cells in situ. Conclusions: Phenotypic changes on human meningioma cells may occur in vitro. This phenomenon suggests caution in transposing the in vitro results to the in vivo condition.