Objective   To investigate the effect of c-maf gene on the MM cells ' proliferation and invasion activity.

  Methods   Lipofectin Reagent was used to transfect c-maf siRNA into multiple myeloma cell of RPMI8226. The mRNA expression level of c-maf was detected by RT-PCR.Cell growth curve was measured by MTT assay. Transwell chamber test was used to measure MM cells ' in vitro invasion activity. The cell cycle distribution were assessed by flow cytomentry. The protein expression levels of survivin，MMP-2, MMP-9, ARK5 and cyclin B1 were detected by Western blot. We also detected the activity of Caspase-3/7.

  Results   The c-maf siRNA was effectively transfected into cells and the mRNA expression of the c-maf gene was inhibited.MTT test and Transwell chamber test showed that the proliferation and in vitro invasion activity of transfected cells were significantly lower than those of other two groups (P＜0.05). Cell cycle of c-maf siRNA transfected group cells was arrested in G2/M phase. The expression levels of survivin，MMP-2，MMP-9，ARK5，cyclin B1 and the activity of Caspase-3/7 between c-maf siRNA transfected group and the other two groups were statistically different (P＜0.05).

  Conclusion   c-maf gene by c-maf siRNA can remarkably inhibit proliferation and invasion of multiple myeloma cell lines of RPMI8226. C-maf gene may be used as the target for multiple myeloma gene therapy.