Amentoflavone inhibits colorectal tumor growth, stemness, and metastasis, prolonging survival through GLI-1/IL6/STAT3 axis targeting.

[BACKGROUND] Colorectal cancer (CRC) is a major malignancy of the colon and rectum. Despite recent clinical advances, continued research is essential to improve therapeutic outcomes. Amentoflavone, a naturally occurring biflavonoid with anti-inflammatory and anti-tumor properties, has shown potential, yet its precise mechanisms and therapeutic efficacy in CRC remain inadequately understood.

[MATERIALS AND METHODS] CT26 and HCT116 cell lines were employed to evaluate the effects of amentoflavone on cell viability, metastasis, and stemness, both in vitro and in vivo.

[RESULTS] A high mutation rate of GLI-1 was observed in CRC patients and was correlated with increased expression of stemness-associated factors. Amentoflavone significantly inhibited GLI-1-mediated CRC cell proliferation, induced G1 phase arrest, and downregulated Cyclin D1/CDK4 expression. It also suppressed metastasis, as evidenced by reduced cell migration, invasion, angiogenesis, and epithelial-mesenchymal transition (EMT), largely through GLI-1 inactivation. Amentoflavone further diminished tumorsphere formation and stemness marker expression. Additionally, the IL-6/STAT3 signaling axis-positively correlated with GLI-1-was also inhibited by amentoflavone. In both xenograft and orthotopic mouse models, amentoflavone markedly reduced tumor growth and improved survival, as confirmed by CT imaging, F-FDG uptake, and Kaplan-Meier analysis. No signs of toxicity were observed, with normal organ histology, stable serum biochemistry (AST, ALT, γGT, CREA), and consistent body weight during treatment.

[CONCLUSIONS] This preclinical study highlights amentoflavone as a promising and safe therapeutic candidate for CRC by targeting the GLI-1/IL-6/STAT3 signaling axis. These findings support further development of amentoflavone as a potential anti-CRC agent.