Construction of a regulatable gene therapy vector specific for hepatocellular carcinoma

Objective To construct a gene modified hepatocellular carcinoma (HCC) specific EGFP expression vector regulated by abbreviated cis acting element of AFP. Methods The DNA segments of minimum essential AFP enhancer and promoter were synthesized through PCR from Genome DNA of HepG2 cells. The gene fragments were then cloned into the multiple cloning site of promoterless EGFP vector pEGFP 1. Recombinant plasmid was transfected into AFP positive or negative cell lines by the means of lipofectamine. The expression of EGFP was tested by fluorescent microscope and flow cytometry. Results By the methods of restriction digestion and sequence analysis, we confirmed that the length, position and orientation of inserted genes of cis acting element of AFP were all correct. The activity of AFP gene promoter was significantly suppressed by the adding of 2 5×10 -7 M all trans retinoic acid (P0 05). Conclusions This recombinant expression vector can be used as a gene therapy vector for HCC. The expression of tumor killing gene will be confined just within the site of tumor and the activity of which can be suppressed by all trans retinoic acid.