[The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02].

Objective: To detect the differential expressions of miR-451, and in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of and , and the mechanism of miR-451 involved in drug resistance in leukemia.

Methods: CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of and in K562 and K562/A02 cells and the transfected groups.

Results: The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher ( <0.001), and the mRNA and protein expression levels of and in K562/A02 cells were significantly higher than those in K562 cells ( <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells ( <0.001), the sensitivity to chemotherapy drugs was significantly enhanced ( <0.05), and the mRNA and protein expressions of and were significantly decreased ( <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells ( <0.001), and the mRNA and protein expressions of and were significantly increased ( <0.01).

Conclusion: There are significant differences in the expressions of miR-451, and between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of and .