Redox Balance in Cancer in the Context of Tumor Prevention and Treatment

Abstract

Malignant neoplasms constitute a substantial health concern for the human population, currently ranking as the second leading cause of mortality worldwide. In 2022, approximately 10 million deaths were attributable to cancer, and projections estimate that this number will rise to 35 million in 2050. Consequently, the development of effective cancer treatments and prevention strategies remains a primary focus of medical research. In this context, the impacts on the redox balance are being considered. The objective of this study was to present the current knowledge on oxidation and reduction processes in cancer. This review discloses the intricate and multifaceted interplay of oxidoreductive systems during carcinogenesis, which engenders discordant findings in the domain of tumor prevention and treatment. This study also examines the controversies surrounding the use of antioxidants, including their impact on other therapeutic interventions. The review offers a comprehensive overview of the existing knowledge on the subject, concluding that personalized and precise anticancer therapies targeting the redox processes can serve as both effective diagnostic and therapeutic tools.

Keywords: antioxidants; cancer; diagnosis; oxidants; prevention; treatment.

Figure 1

The oxidant–antioxidant equilibrium. It is a similar antioxidant/reduction potential to oxidation potential specific for the given tissue. (Created in BioRender. https://app.biorender.com/citation/68121ca6012f4aa59a973e05 (accessed on 30 April 2025)).

Figure 2

Sources of reactive oxygen species within the human body. PAHs: polycyclic aromatic hydrocarbons (e.g., benzopyrene); the Western diet: a diet high in fat and sugar; SOD: superoxide dismutase; NOX: NADPH oxidase; MPO: myeloperoxidase; NOS: nitric oxide synthase; XO: xanthine oxidase; ETC: electron transport chain in mitochondria; ROS: reactive oxygen species (e.g., ¹O₂: singlet oxygen; O₂˙⁻: superoxide anion radical; H₂O₂: hydrogen peroxide; LOOH: lipid hydroperoxide; NO˙: nitric oxide; ONOO⁻: peroxynitrite; ˙OH: hydroxyl radical; HOCl: hypochlorous acid; O₃: ozone). (Created in BioRender. https://BioRender.com/gqj3rqn (accessed on 30 April 2025)).

Figure 3

The antioxidant defense system: conventional division and main elements. In fact, elements of each level of defense collaborate to maintain a balance between all oxidation and reduction reactions (see text for details). EC: enzyme catalog; SOD: superoxide dismutase; CAT: catalase; CP/FOX: ceruloplasmin/ferroxidase; GPX: glutathione peroxidase; PRX: peroxiredoxin; GRX: glutaredoxin; TRX: thioredoxin; MSR: methionine sulfoxide reductase. (Created in BioRender. https://BioRender.com/c1szffk (accessed on 30 April 2025)).

Figure 4

The relationship between cancer survival and development and the redox processes. The development of cancer is contingent upon the appropriate concentration of reactive oxygen species (ROS), which are regulated by antioxidants. Cancer cells may die as a result of excessive concentration of ROS in oxidative-stress-induced processes such as apoptosis, including ferroptosis. Excessive concentration of antioxidants results in a decrease in ROS concentration and inhibition of cancer growth. NRF2: nuclear factor erythroid 2-related factor 2; HIF: hypoxia-inducible factor; AP-1: activator protein-1; AMPK: 5′AMP-activated protein kinase; NF-κB: nuclear factor kappa B. Created in BioRender (Created in BioRender. https://BioRender.com/bo6c888 (accessed on 30 April 2025)).