Cloning and expression of human vascular endothelial growth factor gene and inhibition of its expression by antisense in prokaryotic system

Background and the purpose of the study: Angiogenesis is an important process in physiology and disease pathogenesis and is controlled in a healthy body by a number of stimulatory and inhibitory factors. The aim of this study was to determine the effect of antisense transcript on the sense transcript of the endothelial growth factor (EGF) gene in bacterial system as an approach for the gene regulation in tumors.

Methods: The hepatoma cell line (HepG2) was stimulated by PMA. VEGF mRNA was used for RT-PCR. VEGF cDNA was synthesised and cloned into T-vector pTZ57R, then sense fragment of VEGF subcloned into pACYC Duet-1 expression vector and antisense VEGF subcloned into pCDNA3 expression vector. Recombinant plasmids were transforemed into BL21 bacterial cells. Expression of recombinant plasmid was analysed by western blot technique.

Results: The recombinant pCDNA3-VEGF (pYZantiVEGF) was successfully expressed in BL21 cells. Western blot analysis showed that the expression of VEGF decreased significantly in the cells transfected with VEGF antisense RNA compared with the pACYCDUET-1-VEGF (pYZsenseVEGF) transfected and control.

Major conclusions: The expression of VEGF in BL21 cells was strong. In vitro, antisense of VEGF inhibited VEGF expression significantly in BL21 cells.