title: Polyphosphate blocks tumour metastasis via anti-angiogenic activity.
abstract: PolyP (inorganic polyphosphate) is a linear polymer of many tens or hundreds of orthophosphate residues found in a wide range of organisms, including bacteria, fungi, insects, plants and vertebrates. Despite its wide distribution in mammalian tissues and plasma, the biological functions of polyP on tumour metastasis and angiogenesis have not been previously examined. In the present study, we have shown that polyP effectively blocked in vivo pulmonary metastasis of B16BL6 cells by suppression of neovascularization, whereas it did not affect proliferation or adhesion to extracellular matrix proteins. PolyP not only inhibited bFGF (basic fibroblast growth factor)-induced proliferation and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) activation of human endothelial cells, but also blocked the binding of bFGF to its cognate cell-surface receptor. Furthermore, polyP inhibited bFGF-induced in vitro and in vivo angiogenesis, suggesting that polyP possesses an anti-angiogenic activity. Since neovascularization is essential for tumour metastasis, our present findings clearly indicate that polyP has an in vivo anti-metastatic activity via its anti-angiogenic activity. Taken together with the fact that angiogenesis occurs under various normal and pathological conditions, our observations suggest that endogenous polyP may play a critical role during embryonic development, wound healing and inflammation, as well as in the progress of pathological diseases such as rheumatoid arthritis and cancer.
authors.affiliation: Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: Kyu Yeon
authors.initials: KY
authors.lastname: Han
authors.forename: Bok Sil
authors.initials: BS
authors.lastname: Hong
authors.forename: Yae Jin
authors.initials: YJ
authors.lastname: Yoon
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Yoon
authors.forename: Yoon-Keun
authors.initials: YK
authors.lastname: Kim
authors.forename: Young-Guen
authors.initials: YG
authors.lastname: Kwon
authors.forename: Yong Song
authors.initials: YS
authors.lastname: Gho
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006801:Humans; D008175:Lung Neoplasms / Q000098:blood supply* / Q000556:secondary*; D008297:Male; D008545:Melanoma / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000473:pathology*; D011122:Polyphosphates / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D011122:Polyphosphates; D011956:Receptors, Cell Surface; D016222:Fibroblast Growth Factor 2; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases