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Temporal heterogeneity in oxygen tension in human melanoma xenografts

The spatial heterogeneity of the oxygen tension (pO(2)) in human and experimental tumours has been studied extensively, whereas studies of the temporal heterogeneity in pO(2) are sparse. In the work reported here, pO(2) was measured continuously over periods of at least 60 min in A-07 human melanoma...

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Autores principales: Brurberg, K G, Graff, B A, Rofstad, E K
Formato: Texto
Lenguaje:English
Publicado: Nature Publishing Group 2003
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2394245/
https://www.ncbi.nlm.nih.gov/pubmed/12865929
http://dx.doi.org/10.1038/sj.bjc.6601047
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author Brurberg, K G
Graff, B A
Rofstad, E K
author_facet Brurberg, K G
Graff, B A
Rofstad, E K
author_sort Brurberg, K G
collection PubMed
description The spatial heterogeneity of the oxygen tension (pO(2)) in human and experimental tumours has been studied extensively, whereas studies of the temporal heterogeneity in pO(2) are sparse. In the work reported here, pO(2) was measured continuously over periods of at least 60 min in A-07 human melanoma xenografts by using the OxyLite fibre-optic oxygen-sensing device. The main purpose of the work was to establish the usefulness of the OxyLite system in measuring the temporal heterogeneity in pO(2) in tissues and to characterise the fluctuations in tissue pO(2) in A-07 tumours. The OxyLite device was found to be suitable for studies of the temporal heterogeneity in pO(2) in tumours. However, potential pitfalls were identified, and reliable pO(2) measurements require that precautions are taken to avoid these pitfalls, that is, erroneous pO(2) readings caused by tissue trauma induced by the probe, probe movements induced by reflex actions of the host mouse and occasional probe drift. Significant fluctuations in pO(2) were detected in the majority of the 70 tumour regions subjected to measurement. The fluctuations in different regions of the same tumour were in general temporally independent, implying that they were caused primarily by redistribution of the tumour perfusion rather than fluctuations in global perfusion. Fourier analysis of the pO(2) traces showed that the pO(2) usually fluctuated at frequencies lower than 1.5–2.0 mHz, corresponding to less than 0.1 cycle min(−1). Haemodynamic effects may cause pO(2) fluctuations in this frequency range, and hence, the redistribution of the perfusion could have been caused by morphological abnormalities of the tumour microvasculature. Moreover, acute hypoxia, that is, pO(2) fluctuations around 10 or 5 mmHg, was detected in 20 of 70 regions, that is, 29% (10 mmHg), or 27 of 70 regions, that is, 39% (5 mmHg). The median fraction of the time these regions were acutely hypoxic was 73% (10 mmHg) or 53% (5 mmHg). Consequently, if A-07 tumours are adequate models of tumours in man, acute hypoxia may be a commonly occurring phenomenon in neoplastic tissues, and hence, acute hypoxia is likely to cause resistance to radiation therapy and promote tumour aggressiveness.
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spelling pubmed-23942452009-09-10 Temporal heterogeneity in oxygen tension in human melanoma xenografts Brurberg, K G Graff, B A Rofstad, E K Br J Cancer Experimental Therapeutics The spatial heterogeneity of the oxygen tension (pO(2)) in human and experimental tumours has been studied extensively, whereas studies of the temporal heterogeneity in pO(2) are sparse. In the work reported here, pO(2) was measured continuously over periods of at least 60 min in A-07 human melanoma xenografts by using the OxyLite fibre-optic oxygen-sensing device. The main purpose of the work was to establish the usefulness of the OxyLite system in measuring the temporal heterogeneity in pO(2) in tissues and to characterise the fluctuations in tissue pO(2) in A-07 tumours. The OxyLite device was found to be suitable for studies of the temporal heterogeneity in pO(2) in tumours. However, potential pitfalls were identified, and reliable pO(2) measurements require that precautions are taken to avoid these pitfalls, that is, erroneous pO(2) readings caused by tissue trauma induced by the probe, probe movements induced by reflex actions of the host mouse and occasional probe drift. Significant fluctuations in pO(2) were detected in the majority of the 70 tumour regions subjected to measurement. The fluctuations in different regions of the same tumour were in general temporally independent, implying that they were caused primarily by redistribution of the tumour perfusion rather than fluctuations in global perfusion. Fourier analysis of the pO(2) traces showed that the pO(2) usually fluctuated at frequencies lower than 1.5–2.0 mHz, corresponding to less than 0.1 cycle min(−1). Haemodynamic effects may cause pO(2) fluctuations in this frequency range, and hence, the redistribution of the perfusion could have been caused by morphological abnormalities of the tumour microvasculature. Moreover, acute hypoxia, that is, pO(2) fluctuations around 10 or 5 mmHg, was detected in 20 of 70 regions, that is, 29% (10 mmHg), or 27 of 70 regions, that is, 39% (5 mmHg). The median fraction of the time these regions were acutely hypoxic was 73% (10 mmHg) or 53% (5 mmHg). Consequently, if A-07 tumours are adequate models of tumours in man, acute hypoxia may be a commonly occurring phenomenon in neoplastic tissues, and hence, acute hypoxia is likely to cause resistance to radiation therapy and promote tumour aggressiveness. Nature Publishing Group 2003-07-21 2003-07-15 /pmc/articles/PMC2394245/ /pubmed/12865929 http://dx.doi.org/10.1038/sj.bjc.6601047 Text en Copyright © 2003 Cancer Research UK https://creativecommons.org/licenses/by/4.0/This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material.If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/.
spellingShingle Experimental Therapeutics
Brurberg, K G
Graff, B A
Rofstad, E K
Temporal heterogeneity in oxygen tension in human melanoma xenografts
title Temporal heterogeneity in oxygen tension in human melanoma xenografts
title_full Temporal heterogeneity in oxygen tension in human melanoma xenografts
title_fullStr Temporal heterogeneity in oxygen tension in human melanoma xenografts
title_full_unstemmed Temporal heterogeneity in oxygen tension in human melanoma xenografts
title_short Temporal heterogeneity in oxygen tension in human melanoma xenografts
title_sort temporal heterogeneity in oxygen tension in human melanoma xenografts
topic Experimental Therapeutics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2394245/
https://www.ncbi.nlm.nih.gov/pubmed/12865929
http://dx.doi.org/10.1038/sj.bjc.6601047
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