title: Role of angiopoietin-2 in regulating growth and vascularity of astrocytomas.
abstract: Angiopoietins and Tie2 are angiogenic-specific ligand and receptor complex that have been shown to play a critical role in tumor angiogenesis. Angiopoietin-2 (Ang2) is one of four ligands for receptor Tie2 and it is the naturally occurring antagonist to Tie2, inhibiting the action of Angiopoietin-1 (Ang1). Over the last decade, significant research has focused on elucidating the role of Ang2 in cancer biology and its exact role in tumor angiogenesis remains elusive. In this study we have focused on establishing the role of Ang2 in angiogenesis of malignant astrocytomas. We have demonstrated that Ang2 significantly enhances the vascular growth of malignant astrocytomas and constant upregulation of Ang2 throughout all phases of tumor growth generates abnormal vascular structures that are not typically seen in human astrocytomas, suggesting that Ang2 plays a tumor stage-dependent role and is not a consistently elevated throughout all growth stages of malignant astroctyomas.
authors.affiliation: Arthur & Sonia Labatts Brain Tumor Center, Hospital for Sick Children, University of Toronto, Toronto, Canada M5G 2G4.
authors.forename: Gelareh
authors.initials: G
authors.lastname: Zadeh
authors.forename: Keyvan
authors.initials: K
authors.lastname: Koushan
authors.forename: Qian
authors.initials: Q
authors.lastname: Baoping
authors.forename: Patrick
authors.initials: P
authors.lastname: Shannon
authors.forename: Abhijit
authors.initials: A
authors.lastname: Guha
references.citation: Proc Natl Acad Sci U S A. 2002 Jun 11;99(12):8219-24
references.pmid: 12048246
references.citation: Cardiovasc Res. 2001 Feb 16;49(3):659-70
references.pmid: 11166279
references.citation: Am J Pathol. 2001 Feb;158(2):563-70
references.pmid: 11159193
references.citation: Science. 1997 Jul 4;277(5322):55-60
references.pmid: 9204896
references.citation: Biotechniques. 2001 Jul;31(1):196-202
references.pmid: 11464512
references.citation: Exp Neurol. 1999 Oct;159(2):391-400
references.pmid: 10506510
references.citation: Neoplasia. 2006 May;8(5):419-28
references.pmid: 16790091
references.citation: Semin Cell Dev Biol. 2002 Feb;13(1):19-27
references.pmid: 11969368
references.citation: Am J Pathol. 1998 Nov;153(5):1459-66
references.pmid: 9811337
references.citation: Oncogene. 2000 Sep 14;19(39):4549-52
references.pmid: 11002428
references.citation: Am J Pathol. 2000 Jun;156(6):2179-83
references.pmid: 10854238
references.citation: Brain Pathol. 2005 Oct;15(4):297-310
references.pmid: 16389942
references.citation: Neuro Oncol. 2001 Jan;3(1):1-10
references.pmid: 11305411
references.citation: Lab Invest. 2000 Jun;80(6):837-49
references.pmid: 10879735
references.citation: Cancer Res. 2001 Mar 1;61(5):2145-53
references.pmid: 11280779
references.citation: Int J Oncol. 2003 Sep;23(3):557-65
references.pmid: 12888888
references.citation: Mod Pathol. 2003 Jun;16(6):552-7
references.pmid: 12808060
references.citation: J Tongji Med Univ. 2001;21(3):228-30, 235
references.pmid: 12539584
references.citation: Proc Natl Acad Sci U S A. 2003 Jul 22;100(15):8904-9
references.pmid: 12861074
references.citation: Front Biosci. 2003 Jan 01;8:e128-37
references.pmid: 12456344
references.citation: Oncology (Williston Park). 2002 Apr;16(4 Suppl 3):31-5
references.pmid: 12014866
references.citation: Int J Cancer. 2001 Feb 1;91(3):273-82
references.pmid: 11169947
references.citation: Cancer Res. 2001 Aug 15;61(16):6248-54
references.pmid: 11507079
references.citation: Science. 1999 Jun 18;284(5422):1994-8
references.pmid: 10373119