Figure 5.

AT7519 treatment of Th-MYCN transgenic mice results in massive apoptosis. Th-MYCN transgenic mice were treated with a daily i.p. injection of saline or 15 mg/kg AT7519 (n = 4 per group) for five consecutive days. At 6 h after administration of the last dose, tumour samples were collected for immunohistochemistry analysis of cleaved caspase 3 and hematoxylin-eosin staining. A, stimulatory effect of AT7519 on the pro-apoptotic marker cleaved caspase 3. Quantification was performed by manual counting of the total number of cells and the number of cleaved caspase 3-positive cells in 10 microscopic fields per mouse sample at 40× magnification (30% of each field). The average percentage of cleaved caspase 3-positive cells for each mouse was used to study the inducible effect of AT7519. Statistical differences between the AT7519 treated and saline treated group were calculated using one-tailed unpaired Student’s t-test and are indicated as ** (P < 0.01). B, representative microscopic images of hematoxylin-eosin stained paraffin-embedded tumour sections of saline treated and AT7519 treated mice (n = 4 per group). Magnification of the images: 10×. Scale bar: 200 μm.