fig5

Figure 5. Angiogenic pathways redundancy and endothelial heterogeneity. Intra-tumour endothelial cells, despite being normal, non-neoplastic cells, can be still heterogeneous as far as their biology is concern. Guerrouahen et al.^[74] have demonstrated that endothelial cells from vessels in ovarian carcinoma can considerably differ as far as phosphorylation of AKT is concerned. A:They describe that, following blockage of VEGF, the endothelium with low levels of AKT phosphorylation undergo apoptosis; B: However, in the endothelial cells with high level of phosphor AKT, following the block of VEGF stimulation, the AKT pathway remains active inducing transcription of FGF, an angiogenic factor, which on one side promotes endothelium proliferation and on the other further phosphorylates AKT producing a positive loop. (Based on ^[74]). FGFR: fibroblast growth factor receptor