Objective To observe the effects of DIS3 overexpression or interference on expression of cell cycle and tumor-associated proteins in three types of human myeloma cells. Methods Human myeloma cell lines NCI-H929, RPMI 8226, and U266 were selected as study objects. A DIS3 gene overexpression vector and DIS3-siRNA were designed and constructed. Cell cycle was evaluated by propidium iodide single staining. qRT-PCR and western blotting were employed to detect expression of cyclin B1, P21, CDK2, and tumor-associated proteins MYC, RAS, TP53, and BRAF at mRNA and protein levels, respectively. In addition, activation of the ERK1 / 2 signaling pathway was detected by Western blot. Results Compared with the empty vector group, cells in the DIS3 overexpression group exhibited obvious G0 / G1 phase arrest and decreased expression levels of cycle-related proteins cyclin B1 and CDK2, as well as tumor-related proteins MYC, RAS, TP53, BRAF, and p-ERK1 / 2 (P < 0. 05, P < 0. 01). The expression of P21 was increased (P<0.01) in DIS3 overexpression group. In the siRNA group, trends for each index of mRNA expression or protein expression were opposite to those observed in the DIS3 overexpression group.Conclusions DIS3 overexpression can significantly block G0 / G1 phase in human myeloma cells and reduce expression of tumor-associated proteins, which may be closely related to the inhibition of ERK1 / 2 signaling pathway activation.