Intracranial GBM mouse model

The animal experiments were approved by the Animal Management Rule of the Chinese Ministry of Health (document 55, 2001) and were performed conforming to the approved guidelines and experimental protocols of Nanjing Medical University. U87 cells (1 × 10⁶) stably expressing MCS-firefly luciferase for bioluminescence imaging were transfected with lentivirus expressing control shRNA, shRNA-ANXA2 or shRNA-miR155HG and then were intracranially injected into the frontal lobe of nude mice to generate GBM (n = 10 mice per group). Tumor volumes were measured by luciferase using a bioluminescence imaging system (Caliper IVIS Spectrum, PerkinElmer, Waltham, MA, USA) on days 1, 11, and 21 after implantation. The integrated flux of photons (photons/s) within each region was determined by the Living Images software package (Caliper Life Sciences). Mice were sacrificed when they were in deep coma. Brains were extracted, fixed in 10% formalin and then embedded in paraffin for IHC or frozen at − 80 °C for western blotting or FISH.