The Role of Amino Acids in Non-Enzymatic Antioxidant Mechanisms in Cancer: A Review

Abstract

Currently, the antioxidant properties of amino acids and their role in the physicochemical processes accompanying oxidative stress in cancer remain unclear. Cancer cells are known to extensively uptake amino acids, which are used as an energy source, antioxidant precursors that reduce oxidative stress in cancer, and as regulators of inhibiting or inducing tumor cell-associated gene expression. This review examines nine amino acids (Cys, His, Phe, Met, Trp, Tyr, Pro, Arg, Lys), which play a key role in the non-enzymatic oxidative process in various cancers. Conventionally, these amino acids can be divided into two groups, in one of which the activity increases (Cys, Phe, Met, Pro, Arg, Lys) in cancer, and in the other, it decreases (His, Trp, Tyr). The review examines changes in the metabolism of nine amino acids in eleven types of oncology. We have identified the main nonspecific mechanisms of changes in the metabolic activity of amino acids, and described direct and indirect effects on the redox homeostasis of cells. In the future, this will help to understand better the nature of life of a cancer cell and identify therapeutic targets more effectively.

Frequency of Gene Polymorphisms in Admixed Venezuelan Women with Recurrent Pregnancy Loss: Microsomal Epoxy Hydroxylase (rs1051740) and Enos (rs1799983)

“…These compounds are unstable due to their free electrons [1][2][3]. There are multiple sources of ROS production, such as cellular respiration, inflammatory responses, metabolism of drugs and xenobiotics, exposure to ionising radiation (RX and UV), monoamine oxidase activity, purine catabolism, uric acid production, catalytic reactions supported by different enzymes (xanthine oxidase, NADPH oxidase, nitric oxide synthase, and heme oxidase), nitrogen peroxide formation, and protein synthesis in the rough endoplasmic reticulum (RER) [4][5][6].…”

“…Most nonenzymatic mechanisms are obtained from exogenous sources (vitamin C and E), and the rest are synthesised in the body, such as transferrin, ceruloplasmin, and the glutathione reduction system (tripeptide, L-glutamate, L-cysteine, and glycine). Among all the antioxidant mechanisms, superoxide dismutase, peroxidases, catalase, and thioredoxin are extremely valuable [4][5][6].…”