Figure 6

Angiogenesis and VEGF expression were reduced in tumors derived from survivin-down regulated B16F10 cells: A,B: B16F10 cells stably transfected with shLUC or shSUR2 were used (see Figure3). Cells (3 × 10⁵) were subcutaneously injected in 8–10 week-old C57BL6 mice (6 mice per treatment). Once the tumors reached a volume of approximately 1500mm³ mice were sacrificed, tumors extracted, measured, divided in halves and formalin-fixed for 24 h. After that samples were paraffin-included, sectioned and then slices were de-paraffined and hydrated. A: Samples were stained with arteta, which allows direct visualization of blood vessels. The left panel shows a representative section of a tumor derived from shLUC transfected cells, the center panel, a tumor derived from shSUR2 transfected cells and the right panel, the quantification of average blood vessel density (10 fields per mouse, total 60 fields, * p < 0.05). B: samples were analyzed by immunohistochemistry with anti-VEGF specific antibodies. The left panel shows a representative section of a tumor derived from shLUC transfected cells, the center panel, a tumor derived from shSUR2 transfected cells and the right panel depicts the VEGF-Expression Level Score (ELS) obtained as described in Material & Methods for both conditions (10 samples each condition, * p < 0.05). Magnification bar = 100 μm.