Abstract: ObjectiveTo investigate the effect of macrophage migration inhibitory factor （MIF）targeting small interference RNA （siRNA） on proliferation and apoptosis of gastric cancer SGC7901 cells. 
MethodsSGC7901 cells at logarithmic growth phase were transfected with human MIF siRNA （siMIF group） or negative control sequence （NC group） by liposome method. Western blotting was used to detect the expression of MIF protein at 48 h after transfection. MTT method was used to observe the proliferation at 24， 48 and 72 h after transfection. The apoptotic rate was detected by flow cytometry at 72 h after transfection. Western blotting was used to detect the expression of apoptosisrelated proteins Bcl2 and Bax. 
ResultsAfter transfection for 48 h， the relative expression of MIF protein in siMIF group was 0321±0104， lower than 1078±0212 in NC group， and the difference was statistically significant （P＜005）. The proliferative rates of siMIF group were lower than those of NC group at 4872 h after transfection， and the difference was statistically significant （P＜005）. After transfection of MIF siRNA for 72 h， the apoptotic rate of siMIF group was （235±36）％， higher than （47±17）％ of NC group， and the difference was statistically significant （P＜005）. The relative expression of Bcl2 in siMIF group was 0663±0209， lower than 1129±0178 in NC group， and the relative expression of Bax in siMIF group was 0981±0225， higher than 0587±0254 in NC group， and the above difference was statistically significant （P＜005）. 
ConclusionSiRNA targeting MIF can reduce the expression of MIF protein in SGC7901 cells， inhibit the proliferation and promote apoptosis of SGC7901 cells， and it has a certain prospect in the target therapy of gastric cancer.

Key words: Gastric cancer, Macrophage migration inhibitory factor, Small interference RNA, Proliferation, Apoptosis