[The construction of transferrin receptor- mediated HSV-TK gene transfer system and its effect on human hepatocellular carcinoma cells in vitro].

Objective To construct the localization system involving anti-TfR monoclonal antibody (McAb) and AFP promoters and assess its effect on human hepatoma cell lines. Methods The conjugate of anti-TfR McAb and polylysine (PLL) was made by SPDP and purified by molecular screen chromatography. DNA blocking test determined that the ratio of one pEBAF/tk to six Ab-PLL was the most suitable to couple them. The pEBAF/tk recombinant plasmid bearing HSV-TK gene was coupled to Ab-PLL by noncovalent bond. The pEBAF/tk was transferred into human hepatoma cell line HepG2, SMMC7721 and pulmonary cancer cell line A549 by receptor-mediated gene delivery (Ab-PLL-DNA) and liposome procedure. The growth inhibitory rates of HepG2, SMMC7721 and A549 cells were measured by MTT assay. Results The inhibitory rates of HepG2/tk in 100 mg/L and 1 mg/L of GCV were 60.5% and 24.3%, respectively. The inhibitory rate of GCV to SMMC7721 was 23.2% in 3 days. The pulmonary cancer cell A549, A549/tk(Ab) and A549 /tk (lipo) could not be inhibited by the addition of GCV. Conclusion The localization system employed in this paper has high specificity, effectiveness and safety for gene therapy. It would be a promising strategy for gene therapy.