title: Inhibition of the phosphatidylinositol 3-kinase/Akt pathway by inositol pentakisphosphate results in antiangiogenic and antitumor effects.
abstract: The purpose of this study was to investigate the antiangiogenic and in vivo properties of the recently identified phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor Inositol(1,3,4,5,6) pentakisphosphate [Ins(1,3,4,5,6)P5]. Because activation of the PI3K/Akt pathway is a crucial step in some of the events leading to angiogenesis, the effect of Ins(1,3,4,5,6)P5 on basic fibroblast growth factor (FGF-2)-induced Akt phosphorylation, cell survival, motility, and tubulogenesis in vitro was tested in human umbilical vein endothelial cells (HUVEC). The effect of Ins(1,3,4,5,6)P5 on FGF-2-induced angiogenesis in vivo was evaluated using s.c. implanted Matrigel in mice. In addition, the effect of Ins(1,3,4,5,6)P5 on growth of ovarian carcinoma SKOV-3 xenograft was tested. Here, we show that FGF-2 induces Akt phosphorylation in HUVEC resulting in antiapoptotic effect in serum-deprived cells and increase in cellular motility. Ins(1,3,4,5,6)P5 blocks FGF-2-mediated Akt phosphorylation and inhibits both survival and migration in HUVEC. Moreover, Ins(1,3,4,5,6)P5 inhibits the FGF-2-mediated capillary tube formation of HUVEC plated on Matrigel and the FGF-2-induced angiogenic reaction in BALB/c mice. Finally, Ins(1,3,4,5,6)P5 blocks the s.c. growth of SKOV-3 xenografted in nude mice to the same extent than cisplatin and it completely inhibits Akt phosphorylation in vivo. These data definitively identify the Akt inhibitor Ins(1,3,4,5,6)P5 as a specific antiangiogenic and antitumor factor. Inappropriate activation of the PI3K/Akt pathway has been linked to the development of several diseases, including cancer, making this pathway an attractive target for therapeutic strategies. In this respect, Ins(1,3,4,5,6)P5, a water-soluble, natural compound with specific proapoptotic and antiangiogenic properties, might result in successful anticancer therapeutic strategies.
authors.affiliation: Department of Medicine, The Sackler Institute, University College London, United Kingdom.
authors.forename: Tania
authors.initials: T
authors.lastname: Maffucci
authors.forename: Enza
authors.initials: E
authors.lastname: Piccolo
authors.forename: Albana
authors.initials: A
authors.lastname: Cumashi
authors.forename: Manuela
authors.initials: M
authors.lastname: Iezzi
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Riley
authors.forename: Adolfo
authors.initials: A
authors.lastname: Saiardi
authors.forename: H Yasmin
authors.initials: HY
authors.lastname: Godage
authors.forename: Cosmo
authors.initials: C
authors.lastname: Rossi
authors.forename: Massimo
authors.initials: M
authors.lastname: Broggini
authors.forename: Stefano
authors.initials: S
authors.lastname: Iacobelli
authors.forename: Barry V L
authors.initials: BV
authors.lastname: Potter
authors.forename: Paolo
authors.initials: P
authors.lastname: Innocenti
authors.forename: Marco
authors.initials: M
authors.lastname: Falasca
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen; D004338:Drug Combinations; D004347:Drug Interactions; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D007797:Laminin; D051379:Mice; D008807:Mice, Inbred BALB C; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011509:Proteoglycans; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors* / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D003094:Collagen; D004338:Drug Combinations; D016222:Fibroblast Growth Factor 2; D007295:Inositol Phosphates; D007797:Laminin; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011509:Proteoglycans; D051057:Proto-Oncogene Proteins c-akt; C059485:matrigel; C013571:inositol pentaphosphate