Fig. 3. Genes in HUVECs related to the angiogenic phenotype undergo transcriptional reprogramming when exposed to GFP-U87. Endothelial cells and tumour cells were co-cultured in EBM-2 medium for 0, 5, 12 and 24 hours. RNA was purified from endothelial cells and cDNA array analysis was performed. After normalization and filtration of data, we obtained 290 genes. Ratios of expression were normalized to a +1/–1 scale and data were clustered as described in Materials and Methods. (A) Cell structure/motility/extracellular matrix genes. (B) Receptors for growth factors/cytokines/chemokines. (C) Growth response genes (cell proliferation/cell cycle/DNA repair and recombination). (D) Receptors for secreted ligands. Red corresponds to upregulated genes and green to downregulated genes. Data are from a representative experiment with GF211 arrays as ratios of expression in co-culture to monoculture at 5, 12 and 24 hours of co-cultivation.