Huaier n-butanol extract suppresses proliferation and metastasis of gastric cancer via c-Myc-Bmi1 axis

Gastric cancer (GC) ranks as the third leading cause of cancer-related mortality worldwide, and approximately 42% of all cases diagnosed each year worldwide are diagnosed in China. A large number of clinical applications have revealed that Trametes robiniophila Μurr. (Huaier) exhibits an anti-tumour effect. However, loss of the bioactive components of Huaier during the extraction procedure with water is unavoidable, and the underlying mechanism of the anti-cancer effect of Huaier remains poorly understood. In this study, we investigated the anti-cancer effect of Huaier n-butanol extract, which contained 51.4% total flavonoids, on HGC27, MGC803, and AGS human GC cell lines in vitro. At a low concentration, Huaier n-butanol extract inhibited the growth of these GC cell types, induced cell cycle arrest and reduced cell metastasis. Moreover, Huaier n-butanol extract suppressed the c-Myc-Bmi1 signalling pathway, and overexpression of Bmi1 reversed the effects of Huaier n-butanol extract on GC cells. Thus, our findings indicate that Huaier n-butanol extract suppresses the proliferation and metastasis of GC cells via a c-Myc-Bmi1-mediated approach, providing a new perspective for our understanding of the anti-tumour effects of Huaier. These results suggest that Huaier n-butanol extract could be an attractive therapeutic adjuvant for the treatment of human GC.