Abstract
Background: Patients with acute myeloid leukemia (AML) harboring the DNMT3A-R882 mutation (DR882MUT) are often more difficult to treat and more likely to relapse. However, whether DR882MUT modulates AML progression via circRNAs remains unknown. Methods: Bioinformatics was used to assess the aberrant expression of circRNAs associated with AML. The DR882MUT cell line model was established. circRNA expression in AML cells treated with DR882MUT was analyzed using RT-qPCR. The CCK-8 assay and flow cytometry were used to measure cell proliferation and apoptosis in DR882MUT AML cells after transfection with si-circKCNQ5. The regulatory mechanism of DR882MUT in circKCNQ5 transcription was studied by bisulfite sequencing and ChIP assays. Results: Bioinformatics analysis revealed four abnormally expressed circRNAs associated with AML. Among these, circKCNQ5 was most significantly upregulated in DR882MUT KG-1a HL-60 cells; therefore, circKCNQ5 was selected for this study. circKCNQ5 knockdown remarkably restrained the proliferation and facilitated the apoptosis of DR882MUT KG-1a HL-60 cells compared to cells transfected with si-NC. Moreover, circKCNQ5 knockdown in DR882MUT KG-1a HL-60 cells effectively impeded the total volume and weight of subcutaneous tumor growth in vivo compared to that in cells transfected with si-NC. Furthermore, bisulfite sequencing indicated that the circKCNQ5 promoter methylation level in DR882MUT AML cells was remarkably lower than that in DNMT3A DR882 wild-type AML cells. DR882MUT induced circKCNQ5 transcription by weakening circKCNQ5 promoter methylation. Enhancer of zeste homolog 2 (EZH2) recruited DNMT3A R882 wild-type (DR882WT) to enhance circKCNQ5 methylation. Conclusion: DR882MUT promotes AML progression by inhibiting circKCNQ5 methylation to upregulate circKCNQ5 expression. DR882WT enhanced circKCNQ5 methylation, which requires EZH2 participation.