Combined effects of 5-azacytidine and oleuropein on miR-149-3p, miR-375, miR-574-5p expression and apoptosis in acute myeloid leukemia (AML) cell lines HL-60 and THP-1.

BACKGROUND

Acute myeloid leukemia (AML) is an aggressive hematological malignancy characterized by the rapid proliferation of immature myeloid cells and poor clinical outcomes. Despite conventional treatments such as chemotherapy and hematopoietic stem cell transplantation, relapse and resistance remain major challenges. Epigenetic alterations-particularly dysregulated DNA methylation and microRNA (miRNA) expression- are crucial in AML pathogenesis.

OBJECTIVE

This study aimed to investigate the synergistic effects of azacitidine, a DNA methyltransferase inhibitor, and oleuropein, a natural polyphenol with anticancer properties, on AML cell lines (THP-1 and HL-60).

METHODS

AML cells were treated with azacitidine, oleuropein, or their combination. Cell proliferation was evaluated using MTT assays, apoptosis was assessed via flow cytometry (Annexin V-FITC/PI staining), and miRNA expression levels were quantified using real-time PCR.

RESULTS

Both azacitidine and oleuropein reduced cell viability and induced apoptosis in a dose- and time-dependent manner. The combination treatment significantly enhanced apoptosis, resulting in a 2.5-fold increase in Annexin V-positive HL-60 cells at 72 h. Additionally, the treatment modulated miRNA expression, upregulating miR-149-3p and miR-375, while downregulating miR-574-5p.

CONCLUSION

The synergistic effects of oleuropein and azacitidine suggest a promising therapeutic strategy for AML by targeting epigenetic mechanisms and miRNA pathways. Further in vivo studies and clinical trials are warranted to validate these findings and optimize treatment protocols.