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Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer
VEGF plays a central role in angiogenesis in cancer. Non-small cell lung cancer (NSCLC) tumors have increased microvascular density, localized hypoxia, and high VEGF expression levels; however, there is a lack of understanding of how oncogenic and tumor microenvironment changes such as hypoxia lead...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Biochemistry and Molecular Biology
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501049/ https://www.ncbi.nlm.nih.gov/pubmed/22992725 http://dx.doi.org/10.1074/jbc.M112.397042 |
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author | Deacon, Karl Onion, David Kumari, Rajendra Watson, Susan A. Knox, Alan J. |
author_facet | Deacon, Karl Onion, David Kumari, Rajendra Watson, Susan A. Knox, Alan J. |
author_sort | Deacon, Karl |
collection | PubMed |
description | VEGF plays a central role in angiogenesis in cancer. Non-small cell lung cancer (NSCLC) tumors have increased microvascular density, localized hypoxia, and high VEGF expression levels; however, there is a lack of understanding of how oncogenic and tumor microenvironment changes such as hypoxia lead to greater VEGF expression in lung and other cancers. We show that NSCLC cells secreted higher levels of VEGF than normal airway epithelial cells. Actinomycin D inhibited all NSCLC VEGF secretion, and VEGF minimal promoter-luciferase reporter constructs were constitutively active until the last 85 base pairs before the transcription start site containing three SP-1 transcription factor-binding sites; mutation of these VEGF promoter SP-1-binding sites eliminated VEGF promoter activity. Furthermore, dominant negative SP-1, mithramycin A, and SP-1 shRNA decreased VEGF promoter activity, whereas overexpression of SP-1 increased VEGF promoter activity. Chromatin immunoprecipitation assays demonstrated SP-1, p300, and PCA/F histone acetyltransferase binding and histone H4 hyperacetylation at the VEGF promoter in NSCLC cells. Cultured NSCLC cells expressed higher levels of SP-1 protein than normal airway epithelial cells, and double-fluorescence immunohistochemistry showed a strong correlation between SP-1 and VEGF in human NSCLC tumors. In addition, hypoxia-driven VEGF expression in NSCLC cells was SP-1-dependent, with hypoxia increasing SP-1 activity and binding to the VEGF promoter. These studies are the first to demonstrate that overexpression of SP-1 plays a central role in hypoxia-induced VEGF secretion. |
format | Online Article Text |
id | pubmed-3501049 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | American Society for Biochemistry and Molecular Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-35010492012-11-19 Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer Deacon, Karl Onion, David Kumari, Rajendra Watson, Susan A. Knox, Alan J. J Biol Chem Gene Regulation VEGF plays a central role in angiogenesis in cancer. Non-small cell lung cancer (NSCLC) tumors have increased microvascular density, localized hypoxia, and high VEGF expression levels; however, there is a lack of understanding of how oncogenic and tumor microenvironment changes such as hypoxia lead to greater VEGF expression in lung and other cancers. We show that NSCLC cells secreted higher levels of VEGF than normal airway epithelial cells. Actinomycin D inhibited all NSCLC VEGF secretion, and VEGF minimal promoter-luciferase reporter constructs were constitutively active until the last 85 base pairs before the transcription start site containing three SP-1 transcription factor-binding sites; mutation of these VEGF promoter SP-1-binding sites eliminated VEGF promoter activity. Furthermore, dominant negative SP-1, mithramycin A, and SP-1 shRNA decreased VEGF promoter activity, whereas overexpression of SP-1 increased VEGF promoter activity. Chromatin immunoprecipitation assays demonstrated SP-1, p300, and PCA/F histone acetyltransferase binding and histone H4 hyperacetylation at the VEGF promoter in NSCLC cells. Cultured NSCLC cells expressed higher levels of SP-1 protein than normal airway epithelial cells, and double-fluorescence immunohistochemistry showed a strong correlation between SP-1 and VEGF in human NSCLC tumors. In addition, hypoxia-driven VEGF expression in NSCLC cells was SP-1-dependent, with hypoxia increasing SP-1 activity and binding to the VEGF promoter. These studies are the first to demonstrate that overexpression of SP-1 plays a central role in hypoxia-induced VEGF secretion. American Society for Biochemistry and Molecular Biology 2012-11-16 2012-09-19 /pmc/articles/PMC3501049/ /pubmed/22992725 http://dx.doi.org/10.1074/jbc.M112.397042 Text en © 2012 by The American Society for Biochemistry and Molecular Biology, Inc. Author's Choice—Final version full access. Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) applies to Author Choice Articles |
spellingShingle | Gene Regulation Deacon, Karl Onion, David Kumari, Rajendra Watson, Susan A. Knox, Alan J. Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title | Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title_full | Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title_fullStr | Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title_full_unstemmed | Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title_short | Elevated SP-1 Transcription Factor Expression and Activity Drives Basal and Hypoxia-induced Vascular Endothelial Growth Factor (VEGF) Expression in Non-Small Cell Lung Cancer |
title_sort | elevated sp-1 transcription factor expression and activity drives basal and hypoxia-induced vascular endothelial growth factor (vegf) expression in non-small cell lung cancer |
topic | Gene Regulation |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501049/ https://www.ncbi.nlm.nih.gov/pubmed/22992725 http://dx.doi.org/10.1074/jbc.M112.397042 |
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