Angiogenesis and Cancer
Angiogenesis refers to the formation of new blood vessels due to the development of
existing capillaries and postcapillary veins. Accurately speaking, angiogenesis is not
the same as vasculogenesis, which is the de novo formation of endothelial cells from
mesoderm cell precursors, and neovascularization. The first vessels in the developing
embryo form through vasculogenesis, after which angiogenesis is responsible for
most, if not all, blood vessel growth during development and in disease.
Angiogenesis is a normal and vital process in growth and development, as well as in
wound healing and in the formation of granulation tissue. However, it is also a
fundamental step in the transition of tumors from a benign state to a malignant one,
leading to the use of angiogenesis inhibitors in the treatment of cancer. Tumor
angiogenesis is an extremely complex process that generally includes steps such as
degradation of the vascular endothelial matrix, migration of endothelial cells,
proliferation of endothelial cells, formation of vascular loops by the branching of
endothelial cells, and the formation of a new basement membrane.
Because the neovascular structure and function of the tumor tissue are abnormal,
and the vascular matrix is incomplete, the microvessels are prone to leakage.
Therefore, the tumor cells do not need to go through a complicated invasion process
and penetrate directly into the bloodstream and metastasis. A growing number of
studies have shown that benign tumors have sparse angiogenesis and slow blood
vessel growth, while most malignant tumors have intensive angiogenesis and rapid
growth. Therefore, angiogenesis plays an important part in the development and
metastasis of tumors, and it is a marker for most malignant tumors. Inhibiting this
process will significantly prevent the development and spread of tumor tissue.
