Positron emission tomography imaging sheds new light on hypoxia and antitumor therapies

Abstract

The effect of the hypoxic tumor microenvironment (TME) on the effectiveness of cancer treatments has received widespread attention. It is crucial to investigate the mechanisms by which hypoxia influences the efficacy of these treatments in order to improve the therapeutic outcomes for malignant tumors and the prognoses of patients. Positron emission tomography (PET) imaging is a non-invasive, reproducible, and quantitative imaging technique that can visualize molecular biological changes in vivo. By utilizing specific PET probes, it is possible to both depict in vivo oxygen levels within the TME and evaluate cancer treatment effectiveness at various targets. This review summarizes the effect of hypoxia on various cancer treatments and examines the role of PET imaging in understanding the mechanisms of hypoxia during and after cancer treatments. It is anticipated that this review will provide new insights for improving tumor therapy from the hypoxia perspective and for early prediction and assessment of therapeutic efficacy via PET imaging.

Tumor microenvironment activation amplify oxidative stress promoting tumor energy remodeling for mild photothermal therapy and cuproptosis

“…Compared with conventional PTT, mild PTT reduces the risk of normal tissue damage or inflammation. Therefore, the tumor metabolic reprogramming must be altered to reduce thermal tolerance and maximize the clinical potential of mild PTT and chemotherapy [ [10] , [11] , [12] , [13] , [14] ].…”

Controllable Synthesis of Self-Assembled Nitroimidazole-Based Nanocomplexes for Enhanced Chemodynamic Therapy by Dual-Channel Modulation of Glutathione

“…The Cu 2+ /Cu + -mediated Fenton-like reaction can occur efficiently in weakly acidic and neutral media, and its maximum reaction rate (1 × 10 4 M –1 s –1 ) can be up to 160-fold that of the conventional Fenton reaction inducer Fe 3+ /Fe 2+ . − In addition, Cu 2+ ions consume endogenous GSH, further promoting the Fenton-like reaction. The imidazole derivative 2-nitroimidazole (2-NI) is an anoxic-responsive antitumor drug that can be selectively reduced to 2-amino-imidazole by highly expressed nitroreductase and NADPH in hypoxic tumors, a process that consumes NADPH and impedes the regeneration of GSH. − In recent years, polymeric micellar nanocarriers with side chains containing 2-NI moieties have been developed for the treatment of hypoxic cancer cells. However, low 2-NI loading, and complex synthesis as well as purification processes limit their usefulness. , Therefore, the selection of Cu 2+ ions and 2-NI for coordination self-assembly allows for the delivery of high levels of 2-NI and shows promise for significantly enhanced CDT through dual depletions of GSH and NADPH. − …”