ABSTRACT. We used a simple and efficient method to construct the bicistronic eukaryotic expression vector pIRES2-NGF-VEGF 165 . The nerve growth factor (NGF) gene was obtained from the genomic DNA of human peripheral blood mononuclear cells by polymerase chain reaction. The NGF cDNA fragment was inserted into the multiple cloning sites of the pIRES2-EGFP vector to generate the bicistronic eukaryotic expression plasmid pIRES2-NGF-EGFP. The vascular endothelial growth factor 165 (VEGF 165 ) gene was obtained from the pIRES2-VEGF 165 -EGFP plasmid by polymerase chain reaction. Next, the VEGF 165 cDNA fragment was cloned into pIRES2-NGF-EGFP in place of enhanced green fluorescent protein creating the plasmid pIRES2-NGF-VEGF 165 . pIRES2-NGF-VEGF 165 was transfected into HEK293 cells and reverse transcriptionpolymerase chain reaction and Western blot analysis were used to test the co-expression of double genes. The NGF and VEGF 165 genes were cloned and the DNA was sequenced, which revealed that NGF and VEGF 165 were consistent with the sequence recorded in GenBank. Restriction analysis showed that the NGF and VEGF 165 genes were inserted into the expression vector pIRES2-EGFP. Transfection of pIRES2-NGF-
5675©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (3): 5674-5685 (2014) Construction and identification of pIRES2-NGF-VEGF 165 VEGF 165 into HEK293 cells resulted in expression of the double gene at the mRNA and protein levels. The NGF and VEGF 165 coexpression plasmid provides a novel expression system, enabling further study of the functions of the NGF and VEGF 165 genes.