The inhibitory effect of MIF siRNA on the expression of VEGF in hepatocellular carcinoma cells

Abstract

Objective To investigate the inhibitory effect of macrophage migration inhibitory factor (MIF) small interfering RNA (siRNA) on the expression of vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) cells.Methods The expression of MIF and VEGF in 4 HCC tumor tissues (T) and their peri-tumor tissues (P) was initially detected to provide evidence of simultaneous MIF and VEGF overexpression in HCC tissues.Specific small interfering RNA (siRNA) targeting MIF gene was chemically synthesized,and then transfected at the doses of 50 and 100 nmol/L into HCC cell lines of PLC and HepG2 with Lipofectamine 2000.The control groups of PLC and HepG2 were transfected with the control siRNA.The mRNA and protein expression of MIF and VEGF after siRNAs transfection was examined by quantitative real-time PCR and Western blot.Results MIF and VEGF were overexpressed in the HCC tumor tissues compared with the peri-tumor tissues (P <0.01).In MIF siRNA transfected PLC and HepG2 cells,the mRNA and protein expression of MIF was significantly decreased in a dose-dependent manner.VEGF mRNA was significantly down-regulated in MIF siRNA transfected PLC and HepG2 cells as compared with the control groups (P<0.01).In 50 and 100 nmol/L groups,MIF and VEGF mRNA levels were respectively decreased by (78.8 ± 7.2) %, (60.6 ± 2.6) % and (90.4 ± 2.9) %, (79.8 ± 1.2) % in PLC cells,and (74.3±8.9)% ,(65.6±4.6)% and (88.4±4.6)% ,(80.7±2.2)% in HepG2 cells,respectively.As compared with the control groups, MIF and VEGF protein levels were significantly reduced in the experimental groups (P <0.01) and a statistically significant difference in the protein expression was also found between the two different doses groups of MIF siRNA transfected HCC cells (P < 0.05).Conclusion MIF siRNA could specifically knock down the expression of MIF and efficiently suppress the expression of VEGF in PLC and HepG2 cells.Maybe MIF participate in tumor angiogenesis and enhance carcinoma metastasis via modulation of VEGF gene and protein expression. Key words: Carcinoma,hepatocellular; Macrophage migration inhibitory facto; RNA interfering; Vascular endothelial growth factor