Abstract

The Garcinia multiflora . is not only a delicious fruit that can be consumed directly, but also contains abundant medicinal components in anti-inflammatory and anti-tumor treatments. The objective of this study was to clarify the anti-tumor properties and the underlying mechanism of garciniagifolone A (GA), a polycyclic polyprenylated acylphloroglucinol derived from the edible fruits of Garcinia multiflora, in triple-negative breast cancer (TNBC). Herein, we demonstrated that GA exhibited inhibitory effects on TNBC organoids growth, and suppressed the proliferation, colony formation, migration, and invasion of TNBC cells in vitro . Moreover, GA demonstrated a significant suppression of TNBC growth in vivo without apparent toxicity, and it augmented the anti-tumor efficacy of PTX in both TNBC organoids and xenograft models. GA specifically bound with carbonic anhydrase IX (CA9), a target overexpressed in TNBC and linked to poor prognosis, as confirmed by molecular docking, surface plasmon resonance, and cellular thermal shift assays. Mechanistically, GA binding to CA9 suppresses the PI3K/AKT/mTOR pathway, inducing early-stage autophagy initiation evidenced by increased LC3B-II/I ratio and autophagosomes. However, GA concurrently blocked autophagic flux by inhibiting autophagosome-lysosome fusion, leading to p62 accumulation and reactive oxygen species (ROS) overproduction. Elevated ROS by GA activated the JNK pathway and triggered NLRP3 inflammasome assembly, resulting in caspase-1-mediated cleavage of gasdermin D (GSDMD) and subsequent pyroptosis, alongside caspase-3-dependent apoptosis. Collectively, GA exerted its potent anti-TNBC activity by targeting CA9 to dysregulate autophagy and induce ROS-mediated pyroptosis/apoptosis, presenting a promising low-toxicity therapeutic strategy.