Cryopreservation of organotypic multicellular spheroids from human gliomas.

Fresh human glioma tissue can be cultured on agarose to form organotypic multicellular spheroids (OMS). The major advantage of OMS is the preservation of the cellular heterogeneity and the tumour architecture, which is lost in conventional monolayer cultures. The present study was undertaken to assess the possibilities of storing frozen OMS from seven gliomas which were frozen to determine the viability after thawing. OMS were frozen slowly to -196 degrees C using a programmable freezing machine in culture medium containing 45% serum and 10% of the cryopreservative agent dimethyl sulphoxide (DMSO). After 2 weeks storage at -196 degrees C, quick thawing, and culturing for another week, it appeared that the frozen-thawed OMS were viable and retained their histological characteristics. In addition, it is demonstrated that the cellular constituents of the OMS resumed metabolic and proliferative activities. It is concluded that it is possible to establish frozen stocks of viable glioma OMS. This will enable extensive studies on OMS, such as investigation of the biological behaviour of gliomas by using OMS obtained from primary and corresponding recurrent gliomas. In addition, cryopreservation of OMS makes it possible to correlate the results of in vitro tests on OMS with the patients' responses to similar therapeutic approaches.