Objective: Purpose to investigate the different in vitro function of targetable non-viral vector containing poly-L-lysine or protamine. Methods: Using GV1 and GV2 targetable non-viral vectors, the influences of the poly-L-lysine and protamine on in vitro gene transfer efficiency and the course of gene expression were observed. Results: ?-galactosidase was expressed at intermediate level (50% ) in A375 cells using a complex containing either protamine or poly-L-lysine. Howerver, in case of ABAE cells, ?－galactosidase expression level was low (20% ) transferred with a comPlex containing protamine. On the contrary, ?－ galactosidase expression was at high level (70% ) provided that protamine was replaced with poly-L-lysine. In addition, ?-galac- tosidase activity reached the peak at the 6th day after transfection with the complex containing protamine. The expression was not altered with subsequent subcultures, at least for 3 passages. Using poly-L-lysine, the expression peak in A375 reached the peak at the 7th day after transfection, but the level declined along with subsequent passages of cells. Conclusion: The apllication of protamine in VEGF receptor mediated gene delivery system was limited.

Objective: To investigate the effects of novel targeted non-viral vector in gene therapy of human glioma. Methods: The EGF-R targeting gene delivery system GE7 was constructed. Human Glioma cell line U251 was transfected in vitro with ?－gal as reportor gene and p21 as therapeutic gene using this gene delivery system. By means of the assay of ?-galactosidase staining, Western blotting, in situ end labeling apoptosis cells and DNA ladder, the transferring of exogenous genes and the apoptosis of the tumor cells were examined.Results: It was showed that gene transfer efficiency is over 80%. When transfected with p21 gene, the growth of cells was inhibited significantly, and the apoptosis was detected in the transfected cell by the methods of in situ end labeling and DNA ladder. Conclusion: The GE7 gene delivery system has the ability to transfer exogenous gene to tumor cells and the expression of the therapeutic gene can inhibit the growth of the cells.

Objective To investigate gene transfer efficiency of a novel target non-viral vector GE7 and effects of herpes simplex virus thymidine kinase (HSV 1-tk)/ganciclovir(GCV) mediated by it in vitro. Methods The epidermal growth factor receptor (EGF-R) target gene delivery system GE7 was constructed.Human ovarian cancer cell line CAOV3 was transfected in vitro with ?-galactosidase(?-gal) as reporter gene and HSV 1-tk gene as therapeutic gene using this gene delivery system.By means of the assay of X-gal staining, Northern blotting, cell growth-inhibiting curve and so on,the transferring efficiency of exogenous genes and killing effects are observed. Results It showed that gene transfer efficiency is over 80%.When 10 mg/L GCV was put into ovarian cells transfected with HSV 1-tk gene, 95% of cells were killed, and the apoptosis ratio reached up to 30. Conclusions The GE7 gene delivery system is an effective and safe delivery system.GE7/ HSV 1-tk /GCV therapeutic gene system is appraising for ovarian cancer.

OBJECTIVESTo construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by blocking hepatitis B virus (HBV) with antisense RNA targeting hepatocellular carcinoma.

METHODSGE7 and HA20 were synthesized and mixed with pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system named AFP-enhancing 4-element complex. Nude mice bearing hepatocelluar carcinoma cells HepG2.2.15 were injected with AFP-enhancing 4-element complex via a tail vein. Total RNA from tissues was extracted, and reversal transcription-ploymerase chain reaction (RT-PCR) was used to detect the expression of preS2. Different doses of AFP-enhancing 4-element complex was injected into nude mice at different time points, and tumor diameter was measured.

RESULTSAFP-enhancing 4-element complex was constructed successfully. RT-PCR showed preS2 antisense RNA delivered by AFP-enhancing 4-element complex only expressed in liver tumor HepG2.2.15 cells of the mice. After the treatment of AFP-enhancing 4-element complex with dose of 0.2 micro g per mouse (once a week for 4 weeks), the mean tumor diameter of nude mice was significantly shorter than that of the control groups (0.995 +/- 0.35 cm vs 2.125 +/- 0.25 cm, P < 0.01).

CONCLUSIONSAn HBV antisense RNA gene delivery system targeting hepatocellular carcinoma, AFP-enhancing 4-element complex, was constructed successfully. PreS2 antisense RNA expressed specifically in hepatocelluar carcinoma cells significantly inhibits tumor growth of mice bearing hepatocarcinoma HepG2.2.15 and may have therapeutic potential in HBV related hepatocarcinoma.

Animals ; Drug Delivery Systems ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Hepatitis B Surface Antigens ; therapeutic use ; Hepatitis B virus ; genetics ; Liver Neoplasms, Experimental ; pathology ; therapy ; Male ; Mice ; Mice, Nude ; Protein Precursors ; therapeutic use ; RNA, Antisense ; therapeutic use