Glioblastoma is highly invasive. The Mayo Clinic Brain Tumor Patient-Derived Xenograft National Resource has characterized the invasiveness of many of the patient-derived xenograft models when they're grown as intracranial tumors.
Invasiveness was assessed in two mice for most lines that are reported. For each PDX line, mice with orthotopic tumors were processed for formalin fixation and paraffin embedding. Representative hematoxylin and eosin (H&E) stained coronal brain sections were reviewed to select appropriate samples for staining with a human-specific lamin A/C stain.
Using a DAPI counterstain, invading tumor cells (red in the image) were identified against a blue background.
Incorporating both evaluation of the hematoxylin and eosin and lamin A/C stains, tumor cell infiltration within the brain was scored by a neuropathologist on a scale of 1 to 4 using these criteria:
- 1: Unilateral and well-demarcated
- 2: Fuzzy border or showing movement into other hemisphere, or both
- 3a: Bilateral but restricted to around midline structures
- 3b: Bilateral with clear involvement of both hemispheres
- 4: Largely replacing the brain