FABP4-mediated lipid metabolism promotes TNBC progression and breast cancer stem cell activity.

Metabolic remodeling is a pivotal feature of cancer, with cancer stem cells frequently showcasing distinctive metabolic behaviors. Nonetheless, understanding the metabolic intricacies of triple-negative breast cancer (TNBC) and breast cancer stem cells (BCSCs) has remained elusive. In this study, we meticulously characterized the metabolic profiles of TNBC and BCSCs and delved into their potential implications for TNBC treatment. Our findings illuminated the robust lipid metabolism activity within TNBC tumors, especially in BCSCs. Furthermore, we discovered that Fabp4, through its mediation of fatty acid uptake, plays a crucial role in regulating TNBC lipid metabolism. Knocking down Fabp4 or inhibiting its activity significantly suppressed TNBC tumor progression in both the MMTV-Wnt1 spontaneous TNBC model and the TNBC patient-derived xenograft model. Mechanistically, Fabp4's influence on TNBC tumor progression was linked to its regulation of mitochondrial stability, the CPT1-mediated fatty acid oxidation process, and ROS production. Notably, in a high-fat diet model, Fabp4 deficiency proved to be a substantial inhibitor of obesity-accelerated TNBC progression. Collectively, these findings shed light on the unique metabolic patterns of TNBC and BCSCs, underscore the biological significance of Fabp4-mediated fatty acid metabolism in governing TNBC progression, and offer a solid theoretical foundation for considering metabolic interventions in breast cancer treatment. SIGNIFICANCE: Triple-negative breast cancer progression and breast cancer stem cell activity can be restricted by targeting a critical regulator of lipid responses, FABP4.