Figure 2.

Histologic and immunophenotypic parity between original glioblastoma tissue and patient-derived orthotopic xenografts (PDOXs). (A) Strategy to generate spheres and PDOX from primary glioblastoma tissue. The diagram displays the process of microinjecting sphere cells into the cerebrum region of the mouse brain. The location of burr drilling hole (red circle) in NSG mice skull is demonstrated for microinjections using stereotactic infusion pump resulting in effective (90% take) generation of orthotopic glioblastoma multiforme (GBM) PDOXs. (B) Histological H&E analysis of original patient-derived glioblastoma tissue (patient (Pt) #46) and four different PDOX lines generated from the same patient-derived spheres. Note that the cell density is different in these sections as it depends on the number of cells engrafted into the PDOXs. The lower panels are 1,000× higher magnification of the outlined areas in the top panels. (C) Representative sections for comparison of the expression of stem cell proteins (BMI1, NESTIN, and SOX9) and the proliferation marker Ki67 in the original patient GBM tissue and the corresponding PDOX. Red arrows indicate positive cells. (D) Representative sections for comparison of the clustered expression of the GBM stem cell marker (CD15) in vascular niches and with the hypoxia protein carbonic anhydrase IX (CA9) near blood vessels expressing CD31, both in the original patient GBM tissue and the corresponding PDOX. Black and/or red arrows indicate positive cells. Scale bars are 500 µM in the upper panel of (B) and 20 µM in the lower or magnified panel of (B–D).