RGD Modification Improves the Transfection Efficiency of Adenovirus Vectors Carrying Double Objective Genes

The objective gene and transduction efficiency of a vector are the two key points in gene therapy. Recently, we carried out two-gene combination therapy by inserting two genes in one vector, which can significantly improve antitumor activity. However, bi-cistronic adenovirus may have a low efficiency of transfection and expression. Therefore, in this study, we aimed to construct an adenovirus vector modified with arginine- (R-) glycine-(G-) aspartate (D) (RGD) and to detect and compare the transfection efficiency of the vector carrying two genes: ING4 and PTEN. Based on our previous research results, we first constructed the transfer vector, pAdTrack-CMV-ING4polyA-promoter-PTEN and pAdTrack-CMV-polyA-promoter-PTEN, and we then constructed the homologous recombinant adenovirus plasmids; finally, we obtained a homologous recombinant adenovirus. After PCR and sequence identification, different types of tumor cell lines were infected with these recombinant adenoviruses, and the expression of GFP was detected with fluorescence microscopy and flow cytometry. We successfully constructed adenovirus vectors with RGD modification carrying ING4 and PTEN genes. The GFP expression rate in cells infected with adenovirus containing RGD at 50 MOI was much greater than that of cells infected with adenovirus without RGD modification at 50 MOI. Modification with RGD could significantly improve the transfection efficiency of adenovirus vectors, even those carrying two objective genes, into most tumor cells.