Tumor microenvironments, particularly hypoxia and inflammation, heavily influence colorectal cancer (CRC) pathogenesis by altering polyamine metabolism. Identifying natural compounds targeting these vulnerabilities remains critical. Integrating untargeted metabolomics, network pharmacology, and a human endogenous metabolite library screen, we identified apigenin (API) as a potent anti-CRC candidate. API significantly inhibited the proliferation, migration, and invasion of RKO and HCT116 cells in vitro and suppressed xenograft tumor growth in vivo. Crucially, high-throughput screening revealed that polyamines rescued CRC cells from API-induced cytotoxicity. Mechanistically, API exerts its effects by dismantling a newly identified HIF-1α/SMOX positive feedback loop. In CRC, HIF-1α transcriptionally activates spermine oxidase (SMOX), while SMOX-driven polyamine metabolism fuels the TLR4/MyD88 inflammatory cascade to continuously stabilize HIF-1α. API acts as a “circuit breaker” for this axis, significantly reducing the spermidine/spermine ratio and downregulating inflammatory signaling. Ultimately, API effectively remodels polyamine metabolism and suppresses CRC progression by disrupting the HIF-1α/SMOX and TLR4/MyD88 pathways, offering a novel metabolic mechanism for API in CRC therapy.
Zhang et al. (Fri,) studied this question.