Objective      To observe the interaction between nucleophosmin mutant A (NPM1 mA) and AKT in the cytoplasm

and to investigate the effect of NPM1 mA and AKT on the proliferation of acute myeloid leukemia (AML) cells.       Methods      Co-immunoprecipitation assay was used to explore the interaction between NPM1 mA and AKT. The expression of NPM1 and NPM1 mA in OCI/AML3 cells was knocked down by RNA interference. The expression of p-AKT was suppressed by AKT inhibitor Ⅳ(AKT Ⅳ). Cell proliferation capability was determined by CCK-8 assay.       Results      NPM1 mA interacted with AKT in OCI/AML3 cells. Transfection with the targeting plasmids significantly down-regulated the expression of NPM1 mA and NPM1 proteins in OCI/AML3 cells (P0.05). The cell proliferation capability was significantly suppressed in the leukemia cells with NPM1 interference (P0.05). After treated with AKT Ⅳ

the cell growth was significantly inhibited (P0.05). Combination of knocking-down NPM1 and treating with AKT IV significantly inhibited the cell growth of the OCI/AML3 cells with NPM1 interference (P0.05).       Conclusion      Cytoplasmic NPM1 mA interacts with AKT and regulates the proliferation of AML cells.