title: A role for nucleotides in support of breast cancer angiogenesis: heterologous receptor signalling.
abstract: BACKGROUND
  Human breast carcinoma cells secrete an adenosine 5'-diphosphate transphosphorylase (sNDPK) known to induce endothelial cell tubulogenesis in a P2Y receptor-dependent manner. We examined sNDPK secretion and its effects on human endothelial cells.
  
  
  METHODS
  Nucleoside diphosphate kinase (NDPK) secretion was measured by western blot and enzyme-linked immunosorbent assay, while transphosphorylase activity was measured using the luciferin-luciferase ATP assay. Activation of MAPK was determined by western blot analysis, immunofluorescence and endothelial cell proliferation and migration.
  
  
  RESULTS
  A panel of breast cancer cell lines with origin as ductal carcinoma, adenocarcinoma or medullary carcinoma, secrete sNDPK-A/B. Addition of purified NDPK-B to endothelial cultures activated VEGFR-2 and Erk(1/2), both of which were blocked by inhibitors of NDPK and P2Y receptors. Activation of VEGFR-2 and ErK(1/2) by 2-methylthio-ATP (2MeS-ATP) was blocked by pretreatment with the P2Y(1)-specific antagonist MRS2179, the proto-oncogene non-receptor tyrosine kinase (Src) inhibitor PP2 or the VEGFR-2 antagonist SU1498. Nucleoside diphosphate kinase-B stimulates cell growth and migration in a concentration-dependent manner comparable to the effect of vascular endothelial growth factor. Treatment of endothelial cells with either NDPK-B or 2MeS-ATP induced migration, blocked by P2Y(1), Src or VEGFR-2 antagonists.
  
  
  CONCLUSIONS
  sNDPK supports angiogenesis. Understanding the mechanism of action of sNDPK and P2Y(1) nucleotide signalling in metastasis and angiogenesis represent new therapeutic targets for anti-angiogenic therapies to benefit patients.
authors.affiliation: Department of Pharmacology, Centre for Molecular Medicine, University of Nevada School of Medicine, Mail Stop 573, Reno, NV 89557, USA.
authors.forename: N
authors.initials: N
authors.lastname: Yokdang
authors.forename: J D
authors.initials: JD
authors.lastname: Tellez
authors.forename: H
authors.initials: H
authors.lastname: Tian
authors.forename: J
authors.initials: J
authors.lastname: Norvell
authors.forename: S H
authors.initials: SH
authors.lastname: Barsky
authors.forename: M
authors.initials: M
authors.lastname: Valencik
authors.forename: I L O
authors.initials: IL
authors.lastname: Buxton
mesh_terms: D001943:Breast Neoplasms / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology; D009701:Nucleoside-Diphosphate Kinase / Q000378:metabolism*; D009711:Nucleotides / Q000378:metabolism*; D010766:Phosphorylation; D000090063:Proto-Oncogene Mas; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: C000715470:MAS1 protein, human; D009711:Nucleotides; D000090063:Proto-Oncogene Mas; D040301:Vascular Endothelial Growth Factor Receptor-2; D009701:Nucleoside-Diphosphate Kinase