Reprogramming of amino acid metabolism in breast cancer

Breast cancer is one of the most prevalent malignant tumours, representing a significant health risk for women. Subtyping of breast cancer is based on gene expression profiles, with five distinct subtypes identified Luminal A, Luminal B, HER2-positive, basal-like and normal-like. The heterogeneity of breast cancer represents a significant challenge to its treatment, while drug resistance limits the effectiveness of existing therapies. There is widespread amino acid metabolic reprogramming in breast cancer, and the altered amino acid metabolism observed in breast cancer cells exhibits a heterogeneous metabolic phenotype that differs from normal cells. Consequently, targeting the metabolic differences between breast and normal cells may represent a promising novel anti-cancer strategy. In this article, we review the alterations in the metabolism of amino acids such as glutamine, cystine, serine, glycine, tryptophan and arginine in breast cancer and explore the specific mechanisms by which the aberrant expression of various amino acid metabolism-related enzymes leads to alterations in the proliferative, invasive and metastatic capacities of cancer cells. Finally, we summarise the drugs targeting amino acid metabolism in breast cancer that are currently in preclinical and clinical trials, providing a theoretical basis for targeted therapy of amino acid metabolism.