circ_0061140 regulates the proliferation and apoptosis of multiple myeloma cells through targeting miR-338-3p

Objective To study the effect and regulatory mechanism of circular RNA 0061140 (circ_0061140) on the proliferation and apoptosis of multiple myeloma Sko-007 cells.

Methods The bioinformatics database was used to predict the target miRNA of circ_0061140, and the dual luciferase report experiment was applied to confirm the targeting relationship between circ_0061140 and miR-338-3p.Expression of circ_0061140 and miR-338-3p in the peripheral blood of healthy controls and multiple myeloma patients was analyzed by real-time quantitative PCR.Circ_0061140 small interfering RNA (si-circ_0061140), miR-338-3p mimic, si-circ_0061140 combined with miR-338-3p inhibitor were transfected into Sko-007 cells respectively.The effects of interference with circ_0061140 or miR-338-3p overexpression or inhibition of circ_0061140 and miR-338-3p on Sko-007 cells proliferation and apoptosis were analyzed by CCK-8 method and flow cytometry.Expression of B-cell lymphoma-2 protein (Bcl-2) and Bcl-related x protein (Bax) was detected using Western blotting.

Results MiR-338-3p was the target gene of circ_0061140.The expression of circ_0061140 was significantly increased (P < 0.01), while the the expression of miR-338-3p was significantly reduced (P < 0.01) in in the serum of patients with multiple myeloma compared with healthy controls.The proliferation activity and Bcl-2 expression of Sko-007 cells were significantly reduced (P < 0.01), and the expression of miR-338-3p and Bax, as well as cell apoptosis rate were significantly increased after interfering with circ_0061140 (P < 0.01).The proliferation activity and Bcl-2 expression of Sko-007 cells were significantly reduced (P < 0.01), and the apoptosis rate and Bax expression were significantly increased after overexpression of miR-338-3p (P < 0.01).Compared with interference circ_0061140, cell proliferation activity and Bcl-2 expression of Sko-007 were significantly increased (P < 0.01), and the apoptosis rate and Bax expression were significantly reduced after simultaneously inhibiting the expression of circ_0061140 and miR-338-3p (P < 0.01).

Conclusions Circ_0061140 acts as an oncogene to promote the proliferation and inhibit the apoptosis of multiple myeloma cells through targeting miR-338-3p.