Integrated Single‐Cell RNA Sequencing and Untargeted Metabolomics Reveals β ‐Elemene's Immune and Metabolic Modulation in Triple‐Negative Breast Cancer

ABSTRACT

Triple‐negative breast cancer (TNBC) poses a major challenge in women's health due to its aggressive nature and lack of targeted therapies. β ‐Elemene, a sesquiterpene derived from Curcuma wenyujin , has shown clinical benefits in TNBC, but its mechanisms of action, particularly regarding the immune and metabolic tumor microenvironment, are still poorly defined. In this study, we employed single‐cell RNA sequencing and untargeted metabolomics to investigate how β ‐elemene reshapes the cellular and metabolic landscape of TNBC in a 4T1 orthotopic mouse model. Our results revealed that β ‐elemene inhibited both primary tumor development and pulmonary metastasis in TNBC. Single‐cell analysis identified 11 distinct cell subpopulations, with cancer‐associated fibroblasts (CAFs) showing the most pronounced reduction upon β ‐elemene treatment. Further mechanistic studies indicated that β ‐elemene enhanced antigen presentation in tumor cells while suppressing CAF‐mediated extracellular matrix remodeling and focal adhesion, thereby disrupting their pro‐tumorigenic cellular communication. Additionally, metabolomic profiling revealed a significant downregulation of prostaglandins, including PGH2, PGF2α, PGD2, and PGE2 in the arachidonic acid metabolism pathway, which was critically implicated in immune regulation. The above findings would provide the first comprehensive elucidation of β ‐elemene's dual immunomodulatory and metabolic effects in TNBC, underscoring the potential of natural compounds to augment antitumor immunity.