γ-Elemene Impairs Mitochondrial Biogenesis in Breast Cancer Cells by Upregulating GCN5-Mediated PGC-1α Acetylation

Mitochondrial biogenesis represents a promising therapeutic target in triple-negative breast cancer (TNBC) due to its essential role in cancer cell metabolism and survival. The natural compound γ-Elemene exhibits potent anti-tumor activity, but its effects on mitochondrial regulation in TNBC remain unclear. In this study, we demonstrate that γ-Elemene induces dose-dependent cytotoxicity in MDA-MB-468 and HCC1806 TNBC cells while significantly impairing mitochondrial function, as shown by reduced membrane potential, oxidative phosphorylation capacity, and ATP production. γ-Elemene treatment markedly suppressed mitochondrial biogenesis, decreasing mitochondrial DNA content and downregulating key mitochondrial genes and proteins. These effects were associated with reduced expression of the master regulators NRF1 and TFAM, but independent of PGC-1α expression levels. Mechanistically, γ-Elemene upregulated the acetyltransferase GCN5, leading to enhanced PGC-1α acetylation. This upregulation occurs primarily through increased GCN5 transcription. Genetic ablation of GCN5 completely reversed γ-Elemene-induced PGC-1α acetylation and restored mitochondrial biogenesis and cell viability, establishing a critical role for GCN5 in mediating these effects. Our findings reveal a novel mechanism whereby γ-Elemene disrupts mitochondrial function in TNBC through GCN5-mediated PGC-1α acetylation, providing new insights into its anti-cancer properties and potential therapeutic applications against TNBC.