Figure 4
Tumor biomarkers and microscopic NIRF imaging of panitumumab-IRDye800 in HGG xenograft. (A) Histology (H&E) and immunohistochemistry staining of 4 µm sections of HGG xenograft bearing mouse brains 14 h post panitumumab-IRDye800 injection. EGFR: epidermal growth factor receptor; Ki-67: nuclear protein associated with cellular proliferation; Cldn5: tight junction protein, claudin-5; ERG: erythroblast-transformation-specific related gene (a vascular endothelial marker). Red boxes: primary HGG core and normal brain margin (black dotted line); Blue boxes: HGG cells infiltrating normal brain; Arrows: blood vessels; arrowheads: infiltrating HGG tumor cells. (B) IHC staining index (left Y axis) and Cldn5/ERG ratio (right Y axis, blue) of tumor areas (n = 16) and normal brains (n = 10), respectively (*P < 0.001). (C) NIRF microscopic imaging of intratumoral uptake of panitumumab-IRDye800 (pan800, green) in HGG mouse brain sections in the same field of view as (A). (D) Fluorescence intensity of panitumumab-IRDye800 fluorescence distinguishes tumor from normal brain in (C) with 90% specificity and 83% sensitivity. AUC: area under the curve; ROC: receiver operating characteristic.
