Hypoxia and estrogen are functionally equivalent in breast cancer-endothelial cell interdependence

Molecular Cancer

Research

Robert Suriano¹  Andrea L George¹  Abraham Mittleman¹  Shilpi Rajoria¹  Raj K Tiwari¹ 

[1] Department of Microbiology and Immunology, New York Medical College, 10595, Valhalla, NY, USA;

关键词: Estrogen;    Hypoxia;    Neovasculogenesis;    Vascular endothelial growth factor;    Hypoxia inducible factor;    Breast cancer;   

DOI  :  10.1186/1476-4598-11-80

 received in 2011-12-01, accepted in 2012-10-03,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundRapid breast tumor development relies on formation of new vasculature to supply the growing malignancy with oxygenated blood. Previously we found that estrogen aided in this neovasculogenesis via recruitment of bone marrow derived endothelial progenitor cells (BM-EPCs), leading to increased vessel formation and vascular endothelial growth factor (VEGF) production in vivo. However, the cellular mechanism of this induction and the signaling pathways involved need elucidation.ResultsUsing the murine mammary cell line TG1-1 we observed estrogen (E2) lead to an up regulation of hypoxia inducible factor-1 (HIF-1), an effect abrogated by the anti-estrogen Fulvestrant and the HIF-1 inhibitor YC-1 (3-(5’-hydroxymethyl-2’-furyl)-1-benzylindazole) suggesting the interchangeability of hypoxia and estrogen mediated effects. Estrogen modulation of HIF-1 and subsequent effects on endothelial cells is dependent on the Akt/PI3K pathway and protein synthesis as validated by the use of the inhibitors wortmannin and cycloheximide which abrogated estrogen’s effects respectively. Estrogen treated TG1-1 cells secreted higher levels of VEGF which were comparable to secreted levels from cells grown under hypoxic conditions. Soluble factors in conditioned media from E2 treated breast cancer cells also lead to migration and tube formation of human umbilical vein endothelial cells (HUVEC) in vitro.ConclusionsOur data provide evidence that estrogen signaling mediates the tumor vasculogenic process required for breast cancer progression and involves a key regulator of the hypoxia signaling pathway. Further, hypoxia and estrogen are interchangeable as both similarly modulate epithelial-endothelial cell interaction.

【 授权许可】

Unknown   
© George et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.