Mechanism and application of nonessential amino acid deprivation associated with tumor therapy

Metabolic reprogramming manifested as glycolysis is considered a character of metabolic activity in tumor cells. Glucose used in glycolysis is the major energy source to support the growth and development of tumor cells, contributing to the high glycolytic flux production for the accumulation of cell mass. Of note, beside high consumption of glucose, the glutamine of nonessential amino acids (NEAAs) could be used as a carbon and nitrogen source. However, glucose and glutamine alone are still not enough to serve as the nutritional source for tumors. Other NEAAs are also important, such as serine, asparagine, and arginine. Related studies have confirmed in cells and animal models that either increase or decrease of NEAAs can limit the growth of tumor cells. Therefore, NEAAs deprivation diet has attracted more attention in recent years and it has been gradually applied in clinical practice for further research. In this review, the possible mechanism and potential applications of NEAAs in diet deprivation therapy are summarized, which may provide a direction for the future application in cancer treatment.