Figure 4.

TGF-β-treated U87 cells show distinct tumor morphology and enhanced invasion after intracranial injection in NSG mice when compared with untreated cells, and can be prevented by cotreatment with A8301. (a) Overview of the experimental conditions used for intracranial transplantation. TGF-β (T) and A8301 (I), together with tumor take and the occurrence of neurological symptoms. (b) Immunohistochemical staining using the indicated markers of U87 xenografts. (c) Representative H&E staining of intracranial tumors derived from untreated U87 cells (T−I−), TGF-β-exposed cells (T+I−),TGF-β/A8301-exposed cells (T+I+) and cells exposed to A8301 alone (T−I+). TGF-β-treated tumor grafts showed cells with a more elongated/spindle-shaped cell morphology and appear more loosely packed when compared with nontreated, combined A8301 or A8301-alone-exposed cells. (d) Nestin-stained xenograft-normal brain parenchyma borders show enhanced invasion by groups or individual cells in TGF-β-stimulated U87-derived tumors (T+I−) when compared with the other conditions. (e) Expression of the mesenchymal marker Fibronectin was detected mainly in U87/TGF-β xenografts by immunohistochemistry. The T+I− tumors showed evidence of enhanced neutrophil infiltration (multinucleated cells, arrows) in H&E-stained specimens, and were also associated with increased vascularization and thicker basal membranes when compared with the other conditions visualized after Reticulin staining