Cyclic Hypoxia: An Update on Its Characteristics, Methods to Measure It and Biological Implications in Cancer.

Autor: Bader SB; Department of Oncology, The Oxford Institute for Radiation Oncology, Oxford University, Oxford OX3 7DQ, UK., Dewhirst MW; Radiation Oncology Department, Duke University School of Medicine, Durham, NC 27710, USA., Hammond EM; Department of Oncology, The Oxford Institute for Radiation Oncology, Oxford University, Oxford OX3 7DQ, UK.
Jazyk: angličtina
Zdroj: Cancers [Cancers (Basel)] 2020 Dec 23; Vol. 13 (1). Date of Electronic Publication: 2020 Dec 23.
DOI: 10.3390/cancers13010023
Abstrakt: Regions of hypoxia occur in most if not all solid cancers. Although the presence of tumor hypoxia is a common occurrence, the levels of hypoxia and proportion of the tumor that are hypoxic vary significantly. Importantly, even within tumors, oxygen levels fluctuate due to changes in red blood cell flux, vascular remodeling and thermoregulation. Together, this leads to cyclic or intermittent hypoxia. Tumor hypoxia predicts for poor patient outcome, in part due to increased resistance to all standard therapies. However, it is less clear how cyclic hypoxia impacts therapy response. Here, we discuss the causes of cyclic hypoxia and, importantly, which imaging modalities are best suited to detecting cyclic vs. chronic hypoxia. In addition, we provide a comparison of the biological response to chronic and cyclic hypoxia, including how the levels of reactive oxygen species and HIF-1 are likely impacted. Together, we highlight the importance of remembering that tumor hypoxia is not a static condition and that the fluctuations in oxygen levels have significant biological consequences.
Databáze: MEDLINE
Nepřihlášeným uživatelům se plný text nezobrazuje