The p75 Neurotrophin Receptor Is a Central Regulator of Glioma Invasion (original) (raw)
Figure 2
Microarray Experiments Were Performed to Compare the Gene Expression Differences between the In Vivo–Selected Noninvasive (Tumor) and Invasive Glioma Cells
(A) Table lists results from a representative set of lineage experiments. Four independent microarray experiments were performed, each containing a pair of dye-flipped hybridizations. Genes that displayed consistent gene expression changes (>2-fold change in at least five out of eight hybridizations) are listed. The indicated ratios represent the fold change in gene expression in the invasive compared to the noninvasive cells. Genes chosen for validation are indicated in red.
(B and C) Seven genes were chosen for validation; the expression of five are shown. (B) RT-PCR confirmed the expression of granulocyte colony-stimulating factor (G-CSF), interleukin-8 (IL-8), an unknown hypothetical protein DZFKp434B204 (DZFK), and tissue inhibitor of metalloproteinases-3 (TIMP-3) in the invasive population. Expression levels of GAPDH (unchanged) are shown for comparison. (C) RT-PCR and Western blot confirm expression of p75 in the invasive population (Inv) but not the tumor cell population (T). RT-PCR analysis of GAPDH levels and Western blot analysis of pyruvate kinase levels are included as loading controls. Human dorsal root ganglia (DRG) were used as a positive control.
(D) Addition of NGF (200 ng/ml) enhanced the migratory ability of the invasive glioma cells in matrigel-coated invasion chambers, but had no significant effect on invasion of the tumor cells. Values shown are the mean ± SEM from three independent experiments. Triple asterisks (***) indicate p < 0.001 versus control (two-way ANOVA with Bonferroni post-tests).