miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates proliferation and apoptosis of multiple myeloma cells

Objectives: To investigate the effects of miR-451a targeting interleukin-6 (IL-6) on the proliferation and apoptosis of multiple myeloma (MM) cells and its potential mechanism via JAK2/STAT3 pathway. Methods: mRNA expression of miR451a and IL-6R in the plasma of patients with MM and normal controls were determined by RT-qPCR. U266 cells were cultured, transfected with miR-451a mimics, the proliferative ability of U266 cells was determined by CCK-8. Potential targets of miR-451a were predicted with the biological software TargetScan, and the direct relationship between miR451a and the target IL-6R was analyzed by a dual-luciferase reporter assay. U266 cells were stimulated with IL-6R (100 ng/ml), and the proliferative ability and apoptosis rate were determined by CCK-8 and flow cytometry after 48h. Results: In the plasma of patients with MM, miR-451a expression was low and IL-6R expression was high. miR-451a targeted and negatively regulated IL-6R. Overexpressing miR-451a inhibited the proliferation and promoted the apoptosis of U266 cells. IL-6R acting on U266 cells promoted the proliferation and inhibited the apoptosis of U266 cells. Overexpressing miR-451a inhibited the activation of JAK2/STAT3 pathway and down-regulating miR-451a promoted the activation of JAK2/STAT3 pathway. Conclusions: miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates the proliferation and apoptosis in MM cells.