Characterization of GTML orthotopic tumors.

<p>(<b>A</b>) M10519 GTML spheres (passage 10–27) were orthotopically implanted into the cerebellum of FVB/N mice, and tumor development was monitored by bioluminescence. Once bioluminescence signal were reached at 5x10⁹ photons/s the tumors were either treated with dox to induce MYCN withdrawal or left untreated (n = 6 per treatment arm) and then the level of luciferase expression was monitored until day 26. (<b>B</b>) H&E staining of orthotopic tumors. Mice were treated with dox on day 1 (left panels) on tumors with 5x10⁹ photons/s. Tumor regression at day 26 is shown (right panels). Bars, 500μm (upper panels) and 20μm (lower panels). (<b>C</b>) Immunoperoxidase staining of paraffin-embedded orthotopic tumors. Tumors generated after the implantation of M10519 cells were harvested, paraffin-embedded, sectioned, and labeled with antibodies shown. Sections were counter-stained with hematoxylin. Bar, 20μm.