Placenta Growth Factor (PlGF)

Abstract

PlGF, also called PGF, is a gene encoding placenta growth factor (PlGF) protein, which belongs to VEGF family. This protein was first discovered from human placenta where it is highly expressed to promote placenta growth, thus providing its name –placenta growth factor and later identified to be expressed in many other organs like the heart, brain, thyroid, and skeletal muscle. There are four isoforms of PlGF protein made from alternative splicing of PlGF gene from chromosome 14. PlGF protein may bind to vascular endothelial receptor-1 (VEGFR-1) on monocytes and endothelial cells and stimulates migration of these cells, and thus improves the activity of VEGF, an important protein for human angiogenesis for enhancing vascular permeability, which is one of the main steps for angiogenesis. Because of PlGF potential for promoting angiogenesis, it is suggested that it may be used in skin repair. PlGF is involved in angiogenesis and growth of several kinds of tumours and its blockage inhibited the formation of new vessels at healthy cells around tumours although it did not necessarily result in prevention of primary tumor growth. A treatment with anti-PlGF and anti-VEGF-A antibodies showed similar efficiency against tumor angiogenesis with that with only anti-VEGF-A antibodies. This suggests that the roles of PlGF in tumor angiogenesis might not be as significant as it is believed.