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Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase

BACKGROUND: There is growing awareness that tumour cells build up a “self-advantageous” microenvironment that reduces effectiveness of anti-tumour immune response. While many different immunosuppressive mechanisms are likely to come into play, recent evidence suggests that extracellular adenosine ac...

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Autores principales: Pellegatti, Patrizia, Raffaghello, Lizzia, Bianchi, Giovanna, Piccardi, Federica, Pistoia, Vito, Di Virgilio, Francesco
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440522/
https://www.ncbi.nlm.nih.gov/pubmed/18612415
http://dx.doi.org/10.1371/journal.pone.0002599
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author Pellegatti, Patrizia
Raffaghello, Lizzia
Bianchi, Giovanna
Piccardi, Federica
Pistoia, Vito
Di Virgilio, Francesco
author_facet Pellegatti, Patrizia
Raffaghello, Lizzia
Bianchi, Giovanna
Piccardi, Federica
Pistoia, Vito
Di Virgilio, Francesco
author_sort Pellegatti, Patrizia
collection PubMed
description BACKGROUND: There is growing awareness that tumour cells build up a “self-advantageous” microenvironment that reduces effectiveness of anti-tumour immune response. While many different immunosuppressive mechanisms are likely to come into play, recent evidence suggests that extracellular adenosine acting at A2A receptors may have a major role in down-modulating the immune response as cancerous tissues contain elevated levels of adenosine and adenosine break-down products. While there is no doubt that all cells possess plasma membrane adenosine transporters that mediate adenosine uptake and may also allow its release, it is now clear that most of extracellularly-generated adenosine originates from the catabolism of extracellular ATP. METHODOLOGY/PRINCIPAL FINDINGS: Measurement of extracellular ATP is generally performed in cell supernatants by HPLC or soluble luciferin-luciferase assay, thus it generally turns out to be laborious and inaccurate. We have engineered a chimeric plasma membrane-targeted luciferase that allows in vivo real-time imaging of extracellular ATP. With this novel probe we have measured the ATP concentration within the tumour microenvironment of several experimentally-induced tumours. CONCLUSIONS/SIGNIFICANCE: Our results show that ATP in the tumour interstitium is in the hundrends micromolar range, while it is basically undetectable in healthy tissues. Here we show that a chimeric plasma membrane-targeted luciferase allows in vivo detection of high extracellular ATP concentration at tumour sites. On the contrary, tumour-free tissues show undetectable extracellular ATP levels. Extracellular ATP may be crucial for the tumour not only as a stimulus for growth but also as a source of an immunosuppressive agent such as adenosine. Our approach offers a new tool for the investigation of the biochemical composition of tumour milieu and for development of novel therapies based on the modulation of extracellular purine-based signalling.
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spelling pubmed-24405222008-07-09 Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase Pellegatti, Patrizia Raffaghello, Lizzia Bianchi, Giovanna Piccardi, Federica Pistoia, Vito Di Virgilio, Francesco PLoS One Research Article BACKGROUND: There is growing awareness that tumour cells build up a “self-advantageous” microenvironment that reduces effectiveness of anti-tumour immune response. While many different immunosuppressive mechanisms are likely to come into play, recent evidence suggests that extracellular adenosine acting at A2A receptors may have a major role in down-modulating the immune response as cancerous tissues contain elevated levels of adenosine and adenosine break-down products. While there is no doubt that all cells possess plasma membrane adenosine transporters that mediate adenosine uptake and may also allow its release, it is now clear that most of extracellularly-generated adenosine originates from the catabolism of extracellular ATP. METHODOLOGY/PRINCIPAL FINDINGS: Measurement of extracellular ATP is generally performed in cell supernatants by HPLC or soluble luciferin-luciferase assay, thus it generally turns out to be laborious and inaccurate. We have engineered a chimeric plasma membrane-targeted luciferase that allows in vivo real-time imaging of extracellular ATP. With this novel probe we have measured the ATP concentration within the tumour microenvironment of several experimentally-induced tumours. CONCLUSIONS/SIGNIFICANCE: Our results show that ATP in the tumour interstitium is in the hundrends micromolar range, while it is basically undetectable in healthy tissues. Here we show that a chimeric plasma membrane-targeted luciferase allows in vivo detection of high extracellular ATP concentration at tumour sites. On the contrary, tumour-free tissues show undetectable extracellular ATP levels. Extracellular ATP may be crucial for the tumour not only as a stimulus for growth but also as a source of an immunosuppressive agent such as adenosine. Our approach offers a new tool for the investigation of the biochemical composition of tumour milieu and for development of novel therapies based on the modulation of extracellular purine-based signalling. Public Library of Science 2008-07-09 /pmc/articles/PMC2440522/ /pubmed/18612415 http://dx.doi.org/10.1371/journal.pone.0002599 Text en Pellegatti et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Pellegatti, Patrizia
Raffaghello, Lizzia
Bianchi, Giovanna
Piccardi, Federica
Pistoia, Vito
Di Virgilio, Francesco
Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title_full Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title_fullStr Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title_full_unstemmed Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title_short Increased Level of Extracellular ATP at Tumor Sites: In Vivo Imaging with Plasma Membrane Luciferase
title_sort increased level of extracellular atp at tumor sites: in vivo imaging with plasma membrane luciferase
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440522/
https://www.ncbi.nlm.nih.gov/pubmed/18612415
http://dx.doi.org/10.1371/journal.pone.0002599
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