Description: A-176120 is a potent and selective inhibitor of the farnesyltransferase with IC50 of 1.2+/-0.3 nM. It is more selective over the closely related enzymes geranylgeranyltransferase I (GGTaseI) (IC(50) 423+/-1.8 nM), geranylgeranyltransferase II (GGTaseII) (IC(50) 3000 nM) and squalene synthase (SSase) (IC(50)>10000 nM). A-176120 inhibited ras processing in H-ras-transformed NIH3T3 cells and HCT116 K-ras-mutated cells (ED(50) 1.6 and 0.5 microM, respectively). The anti-angiogenic potential of A-176120 was demonstrated by a decrease in Ras processing, cell proliferation and capillary structure formation of human umbilical vein endothelial cells (HUVEC), and a decrease in the secretion of vascular endothelial growth factor (VEGF) from HCT116 cells. In vivo, A-176120 reduced H-ras NIH3T3 tumour growth and extended the lifespan of nude mice inoculated with H- or K-ras-transformed NIH3T3 cells. .