Le VEGF en physiologie et pathologie thyroïdienne

Abstract

Angiogenesis is a physiological process involving the growth of new vessels from preexisting vasculature. The vascular endothelial growth factor (VEGF) is an important regulator of both benign and malignant disease process in the thyroid gland. The VEGF family includes seven members called respectively VEGF-A, also known as the VPF (vascular permeability factor), VEGF-B, VEGF-C, VEGF-D, all described in mammalians, VEGF-E (found in parapoxviridae), VEGF-F (also called svVEGF, for snake venom VEGF, found in the venom of viper) and PlGF (for placental growth factor). The thyrocytes are able to synthesize and to secrete the VEGF. VEGF-A is implicated in tumour growth and metastasis via blood vessels while VEGF-C and VEGF-D, implicated in lymphangiogenesis, favour metastasis to the cervical lymph nodes during papillary thyroid carcinomas. The importance of VEGF expression could correlate with a poorer outcome in papillary thyroid carcinomas. Because of its important role in malignant angiogenesis, the VEGF is the privileged target of a new variety of therapeutic agents called angiogenesis inhibitors.