ABSTRACT
OBJECTIVE: To construct a non-viral vector for targeting cancer gene therapy. METHODS: The coding sequence of H1s-EGFc was inserted into the expression vectors of Pichia pastoris, and the fusion protein was expressed in secretary way. H1s-EGFc was purified by anion exchange chromatography and size exclusion chromatography. H1s-EGFc fusion protein and "killing gene" expression recombinant pKG plasmid DNA were dissolved in serum-free RPMI-1640 culture to produce H1s-EGFc/pKG complex. HeLa cells, an epidermal growth factor receptor (EGFR) highly expressing cell line, and Jurkat cells, an EGFR non-expressing cell line, were cultured and transfected with H1s-EGFc/pKG complex of different concentrations. Trypan blue staining was used to calculate the number of live cells and the killing rate of H1s-EGFc/pKG. RESULTS: H1s-EGFc fusion protein was constructed and expressed with a purity of over 90%. When the concentrations of H1s-EGFc/pKG complex were 3 microg/ml, 6 microg/ml, and 9 microg/ml respectively the killing rates were 30.6%, 36.2%, and 58.1% respectively. CONCLUSION: The fusion protein H1s-EGFc binds functional gene efficiently and targets it into specific cells. It can be used as non-viral vector in target cancer gene therapy.
