Role of HARP in angiogenesis and possible therapeutic implications.

WARP (heparin affin regulatory peptide), also called pleiotrophin (PTN), be longs to the heparin binding growth factors (HBGFs) family. Several new dat a suggest a role for HARP during the various stages of angiogenesis, In viv o, HARP is localised in endothelial cells of blood capillaries. In vitro WA RP displays mitogenic activity on endothelial cells, induces the formation of capillary-like structures in collagen gel, and degrades extracellular ma trix via stimulation of plasminogen activator activity. HARP is also involv ed in neoangiogenesis during tumor progression. This review discusses the p ossible role of HARP in tumor angiogenesis and its therapeutic implications .