Discovery of the antifungal butoconazole as a potent inhibitor of energy metabolism that drives liver cancer cell death via autophagy impairment

Abstract Metabolic plasticity is a hallmark of cancer cells. Simultaneous inhibition of oxidative phosphorylation and glycolysis is critical to limit tumor aggressiveness and therapy resistance. Recent repositioning of FDA-approved antifungal azoles in oncology highlights their translational potential. However, the antitumor activity and mechanistic basis of butoconazole remain unexplored, and no clinical studies have yet examined butoconazole or related azoles in liver cancer. Here, by integrating transcriptomic, biochemical, and functional assays, we identify butoconazole as a dual disruptor of mitochondrial functionality -via inhibition of Complex II and V- and of glycolytic metabolism in liver cancer, ultimately collapsing cellular bioenergetics. This metabolic exhaustion was accompanied by (i) altered autophagic flux and (ii) a marked suppression of proliferation, clonogenicity, and migration across multiple hepatocellular carcinoma cell lines, ultimately limiting tumor growth in vivo without systemic toxicity at the tested dose. Mechanistically, BN induces inflammatory, oxidative stress, and ATF4-dependent pathways, while downregulating canonical survival signaling, and nucleoporin genes linked with poor prognosis. Collectively, these findings position butoconazole as an efficient candidate for drug repositioning in hepatocellular carcinoma by targeting tumor metabolic flexibility and energy homeostasis.