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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-3-8
pubmed:abstractText
Increased levels of circulating VEGF-A have been demonstrated in patients with non-Hodgkin lymphoma (NHL) and are associated with progressive disease and poor clinical outcome. We investigated the role of VEGF-A in lymphoma tumour growth on a molecular level in order to identify the mechanism of VEGF-A-promoted tumour growth and to identify the potential targets for therapy. We used a model in which Daudi (human Burkitt lymphoma) tumour cells were transduced with VEGF-A165 or an empty vector (negative control) and subcutaneously injected in NOD/SCID mice. The weight of tumours overexpressing VEGF-A was increased 4-fold compared to that of control tumours (p<0.0001), whereas no in vitro growth advantage was demonstrated upon VEGF-A overexpression. VEGF-A-tumours were associated with increased microvessel densities (p=0.004) and increased tumour cell proliferation (Ki67; p<0.001) compared to control tumours. VEGF-A-tumours were characterised by upregulation of phosphorylated STAT-4 and STAT-6 and downregulation of phospho-p27(KIP1), a crucial cell cycle inhibitor (p<0.05). This was accompanied by increased levels of phosphorylated receptor tyrosine kinases, including EGFR (ErbB-2 and ErbB-4, p<0.05), an upstream regulator of STAT proteins. We demonstrated that various mouse-derived cytokines produced by mouse-derived tumour stromal cells are upregulated in VEGF-A-tumours compared to control tumours (p<0.05). These results indicate an important role for the tumour microenvironment in paracrine promotion of lymphoma tumour growth in response to tumour-derived VEGF-A. In conclusion, lymphoma-derived VEGF-A promoted lymphoma tumour growth in a paracrine loop by activation of tumour stromal cells. Our study reveals VEGF-A and STAT proteins as potential additional targets in the treatment of lymphoma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1879-0852
pubmed:author
pubmed:copyrightInfo
Copyright 2009 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
974-82
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
VEGF-A promotes lymphoma tumour growth by activation of STAT proteins and inhibition of p27(KIP1) via paracrine mechanisms.
pubmed:affiliation
Division of Pediatric Oncology/Hematology, Department of Pediatrics, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
pubmed:publicationType
Journal Article