Titre
Tumor-derived vascular endothelial growth factor up-regulates angiopoietin-2 in host endothelium and destabilizes host vasculature, supporting angiogenesis in ovarian cancer.
Type
article
Institution
Externe
Périodique
Auteur(s)
Zhang, L.
Auteure/Auteur
Yang, N.
Auteure/Auteur
Park, J.W.
Auteure/Auteur
Katsaros, D.
Auteure/Auteur
Fracchioli, S.
Auteure/Auteur
Cao, G.
Auteure/Auteur
O'Brien-Jenkins, A.
Auteure/Auteur
Randall, T.C.
Auteure/Auteur
Rubin, S.C.
Auteure/Auteur
Coukos, G.
Auteure/Auteur
Liens vers les personnes
ISSN
0008-5472
Statut éditorial
Publié
Date de publication
2003
Volume
63
Numéro
12
Première page
3403
Dernière page/numéro d’article
3412
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.Publication Status: ppublish
Résumé
Vascular remodeling in host tissues surrounding growing tumors is implicated in the successful development of tumor neovasculature. Cooperation between vascular endothelial growth factor (VEGF) and angiopoietins (Angs) is considered to be critical in this context. However, the mechanisms regulating the coordinated expression of these molecules remain, to date, elusive. In this study, we used a murine ovarian cancer angiogenesis model induced by overexpression of VEGF, as well as 52 human ovarian cancer specimens and 36 established cancer cell lines to characterize the expression and regulation of Ang-2 in the context of tumor angiogenesis. Using a combination of immunohistochemistry, laser capture microdissection and real-time quantitative reverse transcription-PCR, we showed that tumor-derived VEGF significantly up-regulated the expression of Ang-2 in host stroma endothelial cells, resulting in markedly increased Ang-2/Tie-2 mRNA copy number ratio in vivo. In vitro experiments showed that VEGF directly up-regulated Ang-2, which is mediated via VEGF receptor-2/flk-1/KDR pathway, in cultured endothelial cells through transcriptional activation rather than the enhanced mRNA stability. In human ovarian cancer, Ang-2 was primarily expressed in stroma endothelial cells and detectable in tumor cells of only 12% tumor specimens; however, it was not detected in the majority of established ovarian cancer cell lines. In addition, a significant correlation was observed between VEGF and Ang-2 mRNA expression (P < 0.01) but not between VEGF and Ang-1 or Tie-2 in human ovarian cancer specimens. In the mouse ovarian cancer model, up-regulation of Ang-2 in host stroma endothelial cells was significantly associated with pericyte loss and instability of the host vasculature surrounding the tumor. Our study suggests a novel mechanism by which tumor-derived VEGF interacts with Angs/Tie-2 system in host stroma endothelial cells and induces in a paracrine manner the remodeling of host vasculature to support angiogenesis during tumor growth.
Sujets
PID Serval
serval:BIB_09167F2711AD
PMID
Date de création
2014-10-14T10:43:00.451Z
Date de création dans IRIS
2025-05-20T20:27:36Z