2.1. Orthotopic Xenograft Mouse Model

U87MG cells were grown on MEM Eagle growth medium (Sigma-Aldrich Co., St. Louis, MO, United States) supplemented with 10% fetal bovine serum (FBS) (HyClone, Cramlington, UK) using standard conditions (5% CO₂, 37 °C). Male SCID mice aged 6–7 weeks were used. Mice were bred at the Centre for Genetic Resources of Laboratory Animals at the Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, and housed under pathogen-free conditions. Their health status was investigated in accordance with the recommendations of the Federation of European Laboratory Animal Science Associations [6]. Animals had unlimited access to water and food (Ssniff Spezialdiäten GmbH, Soest, Germany). All experiments were performed in compliance with the protocols and recommendations for the correct use and care of laboratory animals (ECC Directive 86/609/EEC). Stereotactically guided intracranial injections in SCID mice were performed by injecting 500,000 U87MG cells at the junction between the cortex and striatum (coordinates, x = –2.0, y = 1.5, z = 2.4; bregma serving as the 0 point for x and y) [7]. Each group contained 8 animals. After 4 weeks, the tumors’ formation was confirmed by magnetic resonance imaging (MRI) on an ultra-high field tomograph, BioSpec 117/16 USR (Bruker Biospin GmbH, Ettlingen, Germany)—11.7 Tesla MRI (Figure 1).

Axial MRI sections of the mice brains 4 weeks after xenotransplantation of U87MG cells. Arrow points to the tumor.