@article {Kim142, author = {Chun-Ki Kim and Yoon Kyung Choi and Hansoo Lee and Kwon-Soo Ha and Moo-Ho Won and Young-Guen Kwon and Young-Myeong Kim}, title = {The Farnesyltransferase Inhibitor LB42708 Suppresses Vascular Endothelial Growth Factor-Induced Angiogenesis by Inhibiting Ras-dependent Mitogen-Activated Protein Kinase and Phosphatidylinositol 3-Kinase/Akt Signal Pathways}, volume = {78}, number = {1}, pages = {142--150}, year = {2010}, doi = {10.1124/mol.110.063586}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {Farnesyltransferase (FTase) inhibitors induce growth arrest and apoptosis in various human cancer cells by inhibiting the post-translational activation of Ras. FTase inhibitors also function to suppress the release of vascular endothelial growth factor (VEGF) from tumor cells by inhibiting Ras activation; however, the effects of FTase inhibitors on VEGF-induced angiogenesis in endothelial cells have not been studied. We have investigated the antiangiogenic effect and molecular mechanism of 4-((1-((1-((4-bromophenyl)methyl)-1H-imidazol-5-yl)methyl)-4-(1-napthalenyl)-1H-pyrrol-3-yl)carbonyl)-(9C1)-morpholine (LB42708), a selective nonpeptidic FTase inhibitor, using in vitro and in vivo assay systems. LB42708 inhibited VEGF-induced Ras activation and subsequently suppressed angiogenesis in vitro and in vivo by blocking the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase/p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt/endothelial nitric-oxide synthase pathways in endothelial cells without altering FAK/Src activation. In addition, this inhibitor suppressed VEGF-induced endothelial cell cycle progression at the G1 phase by suppressing cyclin D1 expression and retinoblastoma phosphorylation as well as up-regulating the cyclin-dependent kinase inhibitors p21 and p27. Knockdown of Ras by short interfering RNA revealed similar inhibitory effects on VEGF-induced angiogenic signal events compared with LB42708. Moreover, the inhibitory effects of LB42708 were significantly higher than those of 4-(2-(4-(8-chloro-3,10-dibromo-6,11-dihydro-5H-benzo-(5,6)-cyclohepta(1,2-b)-pyridin-11(R)-yl)-1-piperidinyl)-2-oxo-ethyl)-1-piperidinecarboxamide (SCH66336), a well known FTase inhibitor. LB42708 suppressed tumor growth and tumor angiogenesis in both xenograft tumor models of Ras-mutated HCT116 cells and its wild-type Caco-2 cells, indicating its potential application in the treatment of both Ras-mutated and wild type tumors. These data indicate that the antitumor effect of LB42708 can be associated with direct inhibition of VEGF-induced tumor angiogenesis by blocking Ras-dependent MAPK and PI3K/Akt signal pathways in tumor-associated endothelial cells.Copyright {\textcopyright} 2010 The American Society for Pharmacology and Experimental Therapeutics}, issn = {0026-895X}, URL = {https://molpharm.aspetjournals.org/content/78/1/142}, eprint = {https://molpharm.aspetjournals.org/content/78/1/142.full.pdf}, journal = {Molecular Pharmacology} }