Induction of ferroptosis by SIRT1 knockdown alleviates cytarabine resistance in acute myeloid leukemia by activating the HMGB1/ACSL4 pathway.

Resistance to cytarabine is a major obstacle to the successful treatment of acute myeloid leukemia (AML). The present study aimed to explore the mechanism by which sirtuin 1 (SIRT1) reverses the cytarabine resistance of leukemia cells. Cell viability was investigated using the EdU proliferation assay. The expression levels of molecules were determined by reverse transcription‑quantitative PCR, western blotting, and immunofluorescence staining. Flow cytometry was used to detect reactive oxygen species and apoptosis levels, The levels of superoxide dismutase, glutathione and malondialdehyde were examined by ELISA. Mitochondrial damage was investigated by transmission electron microscopy. Furthermore, tumor growth was evaluated in a xenograft model. The results revealed that SIRT1 expression was significantly upregulated in drug‑resistant leukemia cells. By contrast, knockdown of SIRT1 reversed cytarabine resistance in HL60 cells by promoting ferroptosis. Mechanistically, SIRT1 could regulate the translocation of HMGB1 from the nucleus to the cytoplasm in cytarabine‑resistant HL60 (HL60/C) cells. Furthermore, knockdown of HMGB1 inhibited the expression of ACSL4. In addition, knockdown of SIRT1 expression could inhibit the growth of HL60/C cells in vivo and reverse cytarabine resistance. In conclusion, the present results demonstrated that SIRT1 inhibition could be a promising strategy to overcome cytarabine resistance in AML.