[MiR-124-3p Enhances the Sansitivity of Chronic Myelogenous Leukemia Cell K562-R to Imatinib by Targeting ABCA2]

Objective: To investigate the effect and mechanism of miR-124-3p-targeing regulating ABCA2 on chronic myelogenous leukemia cell K562-R.

Methods: CML cells with miR-124-3p-overexpression and ABCA2-over-expression as well as subcutaneoustrans planted tumor nude mice were used as study objects. And the CML cells were divided into four groups: K562-R blank control, miR-124-3p mimic control, ABCA2-overexpression and mimic+PC ABCA2. The effects of miR-124-3p and ABCA2 on CML cells were analyzed. The levels of proliferation-, apoptosis- and autophagy- related protein were determined by Western blot. qRT-PCR was employed to detect the levels of miR-124-3p and ABCA2 in K562-R cells. The relationship between miR-124-3p and ABCA2 was validated by luciferase reporter system assays and bioinformatics. Hoechst/immunohistochemical staining and CCK-8 assay were performed to investigate the function involved.

Results: miR-124-3p highly expressed in K562-S cells and lowly expressed in K562-R cells, however, ABCA2 lowly expressed in K562-S cells and highly expressed in K562-R cells. Over-expression of miR-124-3p significantly decreased ABCA2 level and cell growth, but increased autophagy and apoptosis in K562-R cells (P＜0.01). When ABCA2 was over-expressed, the K562-R cell growth was promoted and autophagy and apoptosis were inhibited (P＜0.01). The miR-124-3p promoted cell autophagy and apoptosis but inhibited cell growth in nude mice transplant tumor model (P＜0.01).

Conclusion: miR-124-3p can target ABCA2 to inhibit the growth of CML cells and promote the cell autophagy and apoptosis of CML cells.