Abstract
AIMS: The study aimed to search novel, simple and practical index reflecting the level of essential amino acids (EAAs) metabolism in breast cancer (BC), as well as to explore the effect of enhanced EAAs metabolism on the prognosis and immune microenvironment of BC, thus providing new evidence for the application of EAAs deprivation in the BC treatment. METHODS: The study includes the analysis of multi-omics and clinical data of 13 BC cell lines and 2898 BC patients in the public database. Further validation was performed using multi-omics and immunohistochemistry data from 83 BC tissue samples collected at our hospital. RESULTS: According to the multi-omics data, the SLC7A5 to SLC7A8 Ratio (SSR) score was found to be significantly correlated with the EAAs level and EAAs-metabolic activity of BC, suggesting that the SSR score might be used as a biomarker to assess the degree of EAAs metabolism in BC. Besides, BC patients with high EAAs metabolism had shorter overall survival (OS) time, higher PD-L1 expression, and higher T regulatory cells (Tregs) infiltration, indicating that a high EAAs metabolism was related to a poor prognosis and immune suppression in BC. Additionally, MYC amplification is a critical molecular process in the metabolic reprogramming of EAAs in BC. CONCLUSION: EAAs may be a possible therapeutic target for BC treatment.