Xenograft Model in Nude Mice

The lentivirus-infected U87MG cells (1 × 10⁷) in 100 μL 1× PBS were implanted into 4-week-old BALB/c athymic nu/nu mice (Vital River). Intracranial orthotopic xenografts were established by implanting 5× 10⁵ lenti-U87MG stably transfected cells. The shNC-U87MG and shPTB-AS-U87MG stable transfectants were constructed by our lab. First, the BALB/c athymic nu/nu mice were anaesthetized, and we stereotactically implanted stably infected U87MG cells into the third ventricle (approximately 2 mm lateral and 0.5 mm anterior to the bregma; depth 1.5 mm from the dura). Approximately 1 month later, tumor size was quantified by H&E staining after perfusion. Paraffin-embedded sections of tumors were subjected to standard H&E staining.