Construction of 6HRE-GFAP-Baxα system specific for glioma gene therapy

The aim of this paper is to construct a specific and high-performance gene therapy system for glioma. We constructed a combined promoter 6HRE-GFAP (Hypoxia Responsive Element, Glial Fibrillary Acidic Protein) by gene recombination techniques according to the hypoxia microenvironment in glioma and tested its efficacy and specificity in cultured cells, and then constructed GFAP-Baxα gene expressing system and determined its promoting of apoptosis in glioma cells. Our primary results showed that in U251 and BT325 cell lines, the activity of GFAP promoter was 16.40 and 4.73-fold of the promoter of hTERT (Human Telomerase Reverse Transcriptase), respectively. The activities of 6HRE-GFAP-promoter increased by 3.08 and 1.30-fold under 2% O2 condition compared with those under 18% O2 condition, while under 0.2% O2 condition increased by 8.90 and 2.69-fold, respectively. The glioma cells showed typical apoptotic signs 90 hours after the transient transfection of GFAP-Baxα. In these primary experiments, it showed that 6HRE-GFAP-Baxα system could promote glioma cell apoptosis. It was specific and effective for glioma gene therapy.