PRJNA825377
Implications of hyperoxia on tumor progression: an overview
Hyperoxia is used in order to counteract hypoxia effects in the TME that is described to boost the malignant tumor phenotype and poor prognosis. The reduction of tumor hypoxic state has reached an improvement in the efficacy of therapies such as chemotherapy, through the formation of a non-aberrant vasculature or an increase of the toxicity of the therapeutic agent. Radiotherapy efficacy has also improved, where apoptotic mechanisms seems to be implicated. The antitumor immunity increase thanks to hyperoxia, where diverse pathways leads to an immunopermissive TME. Although hyperoxia is an approved treatment for preventing and treating hypoxemia, it has harmful side effects. Prolonged exposure to high oxygen levels may cause acute lung injury, characterised by an exacerbated immune response, and the destruction of the alveolar-capillary barrier. Furthermore, under this situation the high concentration of ROS may cause toxicity that will lead not only to cell death but also to an increase in chemoattractants and pro-inflammatory cytokines secretion. This would end in a lung leukocytes recruitment, and therefore in lung damage. Unregulated inflammation causes different consequences promoting tumor development and metastasis. This process is known as ProTumor Inflammation, where different cell types and molecules are implicated, for instance, IL1B has been described as a key cytokine. Although current results show benefits over cancer therapies using hyperoxia, further studies need to be done. Not only to improve tumor regression, but also to prevent its collateral damage.