Objective: To compare the transferring efficiency and killing effects of one time and continuous mediation with GE7,a non-viral targeted delivery system,in transfection of thymidine kinase gene of herpes simplex virus (HSV-tk) into ovarian cancer cells. Methods: GE7 was used to prepare recombinants with β-galactosidase (β-gal) and HSV1-tk; the re-combinants were then used to transfect human ovarian cancer line CaOV3 once and continuously. β-gal staining was used to compare the efficiencies of one time and continuous mediation with GE7 system. Ganciclovior (GCV) was introduced into HSV1-tk transfected ovarian cells. Through drawing the cell growth curve and flow cytometry,the killing effects of GCV on once and continuously GE7/HSV1-tk transfected cells were observed. Results: We found that the one time and continuous exogenous gene transfer efficiencies were about 80% and 85%,respectively. When 1μg/mL GCV was used to treat ovarian cell transfected with HSV1-tk gene,growth inhibiting rates of ovarian cells of one time and continuous transferring were 82% and 90%,respectively; their apoptosis indices were 15 and 30,respectively. Under same GCV concentration,continuous me-diation of GE7/pCMV-tk transfection into ovarian cancer cells had more significant inhibitory effect than one time mediation (P<0.05). Conclusion: Compared with one time mediation,continuous mediation of transfection with GE7 gene delivery system has higher efficiency. Continuous mediation of GE7/HSV1-tk/GCV therapeutic gene system has more powerful killing effect.
