Down-regulation Of Macrophage Migration Inhibitory Factor Expression In MCF-7 Cell With Lentivirus-mediated Small Interfering RNA Vectors And The Effect On The Expression Of VEGF-C And Its Mechanism

Objective: The purpose of this study is to structure the lentivirus-mediated small interfering RNA vectors with high transfection efficiency and to study the reduction of macrophage migration inhibitory factor(MIF) expression of MCF-7 cell with lentivirus-mediated small interfering RNA vectors. And then we built the stable low expression MIF breast cancer cells for futher study. We aimed to explore the relationship between MIF and vascular endothelial growth factor-C(VEGF-C) and its mechanism of action.Methods: First of all, we structured the lentivirus-mediated small interfering RNA vectors which can reduce the expression of MIF and transfected it into the breast cancer cells MCF-7. Using inverted fluorescence microscope to observe the fluorescent intensing and state of the cells after transfection. Real-time fluorescent quantitative polymerase chain reaction and Western blot were used to detect the expression of MIF mRNA and protein. The expression of VEGF-C mRNA was detected by real-time fluorescent quantitative polymerase chain reaction, and the expression of VEGF-C protein in the supernatants of breast cancer cells were evaluated by enzyme linked immunosorbent experiment. Moreover, we investigated the expression of p38 MAPK、P-p38 MAPK、p44/42 MAPK、P-p44/42 MAPK in the different groups of cells by Western blot to analysis the regulatory mechanism to VEGF – C.Results: The lentivirus-mediated small interfering RNA vectors were correctly constructed. The transduction rate of lentivirus-mediated small interfering RNA vectors to MCF-7 was more than 80%. It was 72 hours that the fluorescent of cells reached the highest and stable level after transfection. The siRNA can effectively block the expression of MIF mRNA and protein. At the same time, the expression level of VEGF-C was reduced corresponding. Using Western blot to test the stable low expression MIF breast cancer cells, we found that the expression level of p38 MAPK、P-p38 MAPK、p44/42 MAPK、P-p44/42 MAPK had different degree of decrease.Conclusion: The lentivirus-mediated small interfering RNA vectors we constructed have a high transfection rate and can effectively reduce the expression of MIF. MIF can regulate the expression of VEGF-C in breast cancer cells,and its regulatory mechanism may work by activating the MAPK signaling pathway.