[Tumor progression and angiogenesis]

Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis, which underlies tumor progressions such as metastasis. A unique biological feature is that VEGF, mainly produced by malignant cells, hits seemingly non-malignant endothelial cells of host origin. The expression level of VEGF or its receptors appears to be regulated by intrinsic factors such as genetic alterations as well as by extrinsic factors such as pO2 and cytokines. Receptor signals result in coordinated regulation of molecules responsible for growth, differentiation, matrix degradation, migration, adhesion, coagulation, permeability and so forth.