Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Strahlenther Onkol. 2012 Jul;188(7):616-27. doi: 10.1007/s00066-012-0085-4. Epub 2012 Mar 29.
Many tumors contain hypoxic regions. Hypoxia, in turn, is known to increase aggressiveness and to be associated with treatment resistance. The two most frequently described and investigated subtypes of tumor hypoxia are acute and chronic. These two subtypes can lead to completely different hypoxia-related responses within the tumor, which could have a direct effect on tumor development and response to treatment. In order to accurately assess the specific biological consequences, it is important to understand which time frames best define acute and chronic hypoxia.
This article provides an overview of the kinetics of in vitro and in vivo acute and chronic tumor hypoxia. Special attention was paid to differentiate between methods to detect spontaneous in vivo hypoxia and to describe the biological effects of experimental in vitro and in vivo acute and chronic tumor hypoxia.
There are large variations in reported spontaneous fluctuations in acute hypoxia that are dependent on the cell lines investigated and the detection method used. In addition to differing hypoxia levels, exposure times used to induce in vitro and in vivo experimental acute and chronic hypoxia range from 30 min to several weeks with no clear boundaries separating the two. Evaluation of the biological consequences of each hypoxia subtype revealed a general trend that acute hypoxia leads to a more aggressive phenotype. Importantly, more information on the occurrence of acute and chronic hypoxia in human tumors is needed to help our understanding of the clinical consequences.
许多肿瘤都包含缺氧区域。反过来，缺氧已知会增加侵袭性，并与治疗抵抗有关。肿瘤缺氧最常描述和研究的两种亚型是急性和慢性。这两种亚型可能导致肿瘤内完全不同的缺氧相关反应，这可能直接影响肿瘤的发展和对治疗的反应。为了准确评估特定的生物学后果，了解急性和慢性缺氧最好的定义时间框架非常重要。
本文概述了体外和体内急性和慢性肿瘤缺氧的动力学。特别注意区分检测自发体内缺氧的方法，并描述实验性体外和体内急性和慢性肿瘤缺氧的生物学效应。
报告的自发急性缺氧波动存在很大差异，这取决于所研究的细胞系和使用的检测方法。除了缺氧水平不同外，体外和体内实验性急性和慢性缺氧的暴露时间从 30 分钟到数周不等，没有明确的界限将两者分开。对每种缺氧亚型的生物学后果的评估显示出一个普遍的趋势，即急性缺氧导致更具侵袭性的表型。重要的是，需要更多关于人类肿瘤中急性和慢性缺氧发生的信息，以帮助我们了解临床后果。
