EBCs from untreated EBs form highly invasive cortical and ventricular tumors, whereas S18-treated EBCs show enhanced neuronal differentiation after engraftment. (A) A tumor developed from Vybrant CM diI-labeled ROSA-26 EBCs was immunostained for β-galactosidase (Cy2, green). The arrow indicates a residual cluster of Vybrant CM diI-labeled cells. (B) S18-treated or untreated EBCs were stained with Vybrant CM diI (red, untreated cells) or Vybrant diO (green, treated cells), mixed, and injected into the striatum of neonatal mice. The figure shows settlement of treated cells in the subependymal layer, whereas untreated EBCs form a neural tube-like tumor in the lumen of the right lateral ventricle. (C) Mouse EBCs derived from S18-treated EBs were injected into the striatum of neonatal mice and immunostained for nestin (Cy3, red). (D) After nestin staining, frozen sections were FISH-stained for Y-chromosomes (FITC, green). DNA was counterstained with Hoechst dye (blue). (E) Mouse EBs were treated with 80 μM of S18, labeled with Vybrant CM diI (red), and injected into the striatum of neonatal mice. 6 wk after engraftment, brain sections were immunostained for β-tubulin III (Cy2, green). Arrrow shows cluster of Vybrant CM diI-positive (red) cells that are double-stained for β-tubulin III (Cy2, cryosectioned, confocal).