Clinical significance of FoxO1 expression and its regulation in dihydroartemisinin treatment in liver cancer

Background: The transcription factor Forkhead Box O 1 (FoxO1) is crucial to numerous cellular and biological functions. Dihydroartemisinin (DHA) is a derivative of artemisinin extracted from Chinese medicinal plants. The regulatory mechanism of FoxO1 in liver cancer and its relationship with DHA treatment remain unclear. Objectives: This study aims to investigate the role of FoxO1 in liver cancer and DHA treatment. Methods: The expression levels of FoxO1 and its correlation with overall survival were evaluated using the public databases and experiments. The regulation of DHA on FoxO1 was investigated by MTT, Western blotting, immunofluorescence staining, colony formation assays, CRISPR/Cas9 and siRNA-mediated gene knockdown. Results: FoxO1 expression was markedly reduced in hepatoma tissues and associated with higher overall survival. FoxO1 expression was diminished in advanced-stage hepatoma tissues. DHA enhanced FoxO1 expression, concomitant with a reduction in p-AKT and its downstream target p-mTORC1. DHA activity was decreased in FoxO1-knockdown cells. Interestingly, knockdown of Sirt2 abolished DHA-induced FoxO1 expression and impaired the anticancer effect of DHA, which may be correlated with FoxO1 ubiquitination regulation. The p38 MAPK signalling pathway is crucial for the tumor-suppressing effects of DHA and the translocation of FoxO1. Conclusion: The findings indicated that DHA could impede the development of liver cancer through FoxO1 regulation, suggesting that targeting FoxO1 may represent a promising therapeutic approach for liver cancer treatment.