High expression of lnc-CRNDE presents as a biomarker for acute myeloid leukemia and promotes the malignant progression in acute myeloid leukemia cell line U937.

OBJECTIVE: To detect the expression of long non-coding RNA-CRNDE in patients with acute myeloid leukemia and its effect on proliferation and apoptosis in acute myeloid leukemia cell line U937.

PATIENTS AND METHODS: 81 cases of newly diagnosed acute myeloid leukemia (AML) were enrolled, and 35 non-malignant hematological patients were selected as controls. Quantitative RT-PCR (qRT-PCR) was performed to detect the expression of lncRNA-CRNDE in the bone marrow specimens of the subjects, and the difference between the two groups was also compared. The correlation between the expression of lncRNA-CRNDE and the sex, age, classification and total survival of clinical patients was analyzed according to the clinical data. U937 cells and monocytes isolated from normal people were cultured, and the expression of lncRNA-CRNDE in acute myeloid leukemia cell line U937 and normal monocytes was compared. SiRNA-CRNDE and pcDNA-CRNDE were transfected into U937 cells, and cell counting kit-8 (CCK-8) assay was performed to detect proliferation of U937 cells, Annexin V/PI flow cytometry was carried out to detect cell apoptosis. Cell cycle was measured by flow cytometry.

RESULTS: The expression of lncRNA-CRNDE in patients with AML and U937 cells was significantly higher than that in non-malignant hematological controls. Results of clinical data showed that the expression of lncRNA-CRNDE was associated with the classification and total survival of myeloid leukemia in clinical patients. After transfection of siRNA-CRNDE, the proliferation and cloning ability of U937 cells decreased, while the apoptosis increased (p < 0.01) and cells were arrested in G0-G1 phase. Meanwhile, after transfection of pcDNA-CRNDE, the proliferation ability of U937 cells increased significantly, which indicated that the expression of lncRNA-CRNDE might play an essential role in promoting the proliferation of U937 cells.

CONCLUSIONS: LncRNA-CRNDE is highly expressed in the bone marrow tissues of AML patients, and the expression level is negatively correlated with the total survival of those clinical patients. Meanwhile, the expression is higher in FAB type M4 and M5 than that in M1, M2 and M3. LncRNA-CRNDE promotes the proliferation and cell cycle of U937 cells, and inhibits cell apoptosis, which is expected to become a molecular marker for predicting and treating AML.