Objective: To explore the expression level and potential clinical significance of murine double minute 2 (MDM2) circular RNA (circ-MDM2) in bone marrow specimens of patients with acute myeloid leukemia (AML). Methods: Expression level of circMDM2 in bone marrow mononuclear cells (BMMNCs) of 92 AML patients and 22 controls was detected by quantitative real-time PCR. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of circ-MDM2 expression. The association between the expression level of circ-MDM2 and the clinical parameters of AML patients was analyzed. Kaplan-Meier curve was used to analyze the influence of circ-MDM2 on overall survival and leukemia-free survival. Results: Compared with the control group, circ-MDM2 was significantly increased in AML patients (P<0.05). According to the ROC curve result, the area under curve of circ-MDM2 for diagnosing AML was 0.649, and the expression level of circ-MDM2 could distinguish AML patients from controls (P=0.03). Mutation rate of CEBPA in circ-MDM2 low expression group was significantly higher than that in circ-MDM2 high expression group (P=0.039). Overall survival and leukemia-free survival of patients in high-expressed circ-MDM2 group and low-expressed circ-MDM2 group were not statistically significant (P>0.05). Conclusion:  circ-MDM2 was significantly up-regulated in AML patients and could be used as a potential biomarker for the diagnosis of AML.

［Key words］acute myeloid leukemia; MDM2; circular RNA; bone marrow mononuclear cells