Effects Of MIF SiRNA On Hepatic Metastasis Of Mouse Colonic Cancer

Objective: TO investigate the effects of MIF siRNA ,a small interfering RNA(siRNA)targeting MIF on hepatic metastasis in a BALB/c mouse model of colonic cancer. Methods: 1.To obtain solid tumor. 2.Orthotopic transplantation of fresh colorectal cancer tumor fragments into hernial sac of cecum was used in a BALB/c mouse model of colorectal cancer. 3.Thirty mouse models were divided randomly into three groups and treated respectively with MIF siRNA(0.15ng/kg), NC-MIF siRNA and NS twice a week, intratumorally. 4.After four weeks ,mice were sacrificed and the whole livers were made into serial slices to detect the occurrence of hepatic metastasis.5.ELISA was used to test the serum MIF and VEGFconcentrations.6.Imm-unohistochemical staining of CD31 was used for comparing microvessel density of the tumor tissue. Results: Compared with NS-siRNA and NS treatment , MIF siRNA decreased the occurrence of hepatic metastasis (10%,60% and 70%, respectively ; x~2=8.30,p<0.05). Also MIF siRNA decreased serum MIF levels (20±4)pg/ml,(72±8)pg/ml and(78±7)pg/ml , respectively ; p<0.05 and VEGF levels(20±4)pg/ml,(77±9)pg/ml,(77±10)pg/ml, respectively ;p<0.05 .The MVD of hepatic tumor tissues are (19±3),(29±6)and(35±7),respectively; p <0.05. Conclusion: MIF siRNA reduced the occurrence of hepatic metastasis, possibly by a mechanism of MIF siRNA inhibiting the expression of MIF, down-regulating the expression of VEGF and reducing MVD.