Erschienen in:
01.12.2010 | Original Paper
Targeting NF-κB in infantile hemangioma-derived stem cells reduces VEGF-A expression
verfasst von:
Shoshana Greenberger, Irit Adini, Elisa Boscolo, John B. Mulliken, Joyce Bischoff
Erschienen in:
Angiogenesis
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Ausgabe 4/2010
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Abstract
Background
Infantile hemangioma (IH) is a most common tumor of infancy. Using infantile hemangioma-derived stem cells (HemSCs), we recently demonstrated that corticosteroids suppress the expression of VEGF-A, monocyte chemoattractant protein-1 (MCP-1), urokinase plasminogen activator receptor (uPAR), and interleukin-6 (IL-6); each of these are known targets of the transcription factor nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB). In the present study, we examined the expression of these NF-κB target genes in IH tissue specimens and the effect of NF-κB regulation on the expression of pro-angiogenic cytokines, and in particular VEGF-A, in HemSCs.
Materials and methods
RNA extracted from IH tissue and hemangioma-derived stem cells (HemSCs) was used to analyze NF-κB target gene expression by reverse transcription–quantitative PCR (RT-qPCR). The effects of NF-κB blockade were examined in HemSCs. Immunostaining, immunoblotting and ELISA were used to assess protein expression.
Results
MCP-1, uPAR, and IL-6 were found to be differentially expressed in proliferating versus involuting IH. Corticosteroids suppressed NF-κB activity of HemSCs. Velcade (Bortezomib), a proteosome inhibitor that can indirectly inhibit NF-κB, impaired HemSCs viability and expression of pro-angiogenic factors. Furthermore, specific inhibition of NF-κB resulted in suppression of VEGF-A.
Conclusions
We demonstrate expression of NF-κB target genes in proliferating IH. In addition, we show that the expression of several pro-angiogenic factors in HemSCs, and in particular VEGF–A, is regulated by NF-B activity.