Abstract
Biopsies from patients with cutaneous T-cell lymphoma (CTCL) exhibit stage-dependent increase in angiogenesis. However, the molecular mechanisms responsible for the increased angiogenesis are unknown. Here we show that malignant CTCL T cells spontaneously produce the potent angiogenic protein, vascular endothelial growth factor (VEGF). Dermal infiltrates of CTCL lesions show frequent and intense staining with anti-VEGF antibody, indicating a steady, high production of VEGF in vivo. Moreover, the VEGF production is associated with constitutive activity of Janus kinase 3 (Jak3) and the c-Jun N-terminal kinases (JNKs). Sp600125, an inhibitor of JNK activity and activator protein-1 (AP-1) binding to the VEGF promoter, downregulates the VEGF production without affecting Jak3 activity. Similarly, inhibitors of Jak3 inhibit the VEGF production without affecting JNK activity. Downregulation of Stat3 with small interfering RNA has no effect, whereas curcumin, an inhibitor of both Jak3 and the JNKs, almost completely blocks the VEGF production. In conclusion, we provide evidence of VEGF production in CTCL, which is promoted by aberrant activation of Jak3 and the JNKs. Inhibition of VEGF-inducing pathways or neutralization of VEGF itself could represent novel therapeutic modalities in CTCL.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Line, Tumor
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Curcumin / pharmacology
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Enzyme Inhibitors / pharmacology
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Gene Expression Regulation, Neoplastic
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Humans
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Hypoxia-Inducible Factor 1, alpha Subunit / genetics
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Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
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JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
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JNK Mitogen-Activated Protein Kinases / genetics
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JNK Mitogen-Activated Protein Kinases / metabolism*
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Janus Kinase 3
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Lymphoma, T-Cell / metabolism*
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Lymphoma, T-Cell / physiopathology
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Lymphoma, T-Cell / therapy
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Neovascularization, Pathologic / metabolism
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Neovascularization, Pathologic / physiopathology
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Neovascularization, Pathologic / therapy
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Protein-Tyrosine Kinases / antagonists & inhibitors
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Protein-Tyrosine Kinases / genetics
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Protein-Tyrosine Kinases / metabolism*
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RNA, Messenger / metabolism
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STAT3 Transcription Factor / genetics
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STAT3 Transcription Factor / metabolism
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Skin Neoplasms / metabolism*
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Skin Neoplasms / physiopathology
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Skin Neoplasms / therapy
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Sp1 Transcription Factor / genetics
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Sp1 Transcription Factor / metabolism
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Sp3 Transcription Factor / genetics
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Sp3 Transcription Factor / metabolism
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Transcription Factor AP-1 / genetics
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Transcription Factor AP-1 / metabolism
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Transcription Factor AP-2 / genetics
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Transcription Factor AP-2 / metabolism
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Transfection
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Vascular Endothelial Growth Factor A / genetics*
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Vascular Endothelial Growth Factor A / metabolism
Substances
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Enzyme Inhibitors
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HIF1A protein, human
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Hypoxia-Inducible Factor 1, alpha Subunit
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RNA, Messenger
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SP3 protein, human
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STAT3 Transcription Factor
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STAT3 protein, human
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Sp1 Transcription Factor
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Transcription Factor AP-1
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Transcription Factor AP-2
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VEGFA protein, human
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Vascular Endothelial Growth Factor A
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Sp3 Transcription Factor
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Protein-Tyrosine Kinases
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JAK3 protein, human
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Janus Kinase 3
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JNK Mitogen-Activated Protein Kinases
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Curcumin