The mechanisms of angiogenesis in hepatocellular carcinoma: Angiogenic switch during tumor progression

Solid tumors constantly require a vascular supply for their progression and metastasis. Hepatocellular carcinoma (HCC) is known to gain its hypervascularity during the process of dedifferentiation and progression. Various angiogenic growth factors and inhibitors regulate this angiogenic switch of HCC. The known endothelial cell-specific growth factors and their receptors can be classified into the vascular endothelial growth factor and angiopoietin families. Both vascular endothelial growth factors and angiopoietins have been found to work cooperatively, and both are essential for HCC angiogenesis. Because small and ill-vascularized HCCs slowly progress and only rarely metastasize, antiangiogenic therapy could therefore be a promising anticancer strategy for HCC.