Cytotoxic effect of unclassified group K rotaviruses on T98G and U87MG glioblastoma cells in vitro.

Abstract

e15597 Background: Oncolytic virotherapy is developing intensively in modern oncology. Viruses demonstrate the ability to the direct oncolysis and to the stimulation of antitumor immune activity; this experiment was aimed at solving the question of the prevalence of one of them. Glial tumors are the most common brain tumors; oncolytic viruses show certain prospects in their treatment due to the ability to penetrate the blood-brain barrier. The aim of the study was to determine the possible oncolytic effect of new unclassified group K rotaviruses (RVK) on T98G and U87MG glioblastoma cells in vitro. Methods: T98G and U87MG cell cultures were received from Russian banks of cell lines of human and animal tissues. Standard culturing was performed with attenuated apatogenic RVK strains No. 100 and No. 228 at a concentration of 108, 107, 106 and 105 particles/mL. The cytotoxic effect was determined with MTT and Annexin V assays, cell morphology was evaluated by the light-optical method. Results: Both RVK strains demonstrated a dose-dependent cytotoxic activity; the maximal effect was observed in strain No.100 at a dose of 108 particles/mL on U87MG cells (predominantly apoptosis). Studies of cell morphology showed a pronounced effect of RVK on the cell culture: significant degenerative changes in cells, a tendency to a decrease in cluster size, a change in their shape and granularity. Cluster formation in culturing in the serum-free medium is considered in the literature as a property of cancer stem cells responsible in vivo for tumor recurrence and its chemo- and radio-resistance. T98G cells demonstrated morphological changes: nuclear segmentation, diffused cytoplasm, indistinct cell borders with signs of syncytium formation. Conclusions: The established oncolytic effect of RVK strain No. 100 in vitro on glioma cells, presumably with tumor stem cells, indicates a significant potential for the use of these rotaviruses in treatment of glial tumors.