[Evaluation of GE7-transferring system-mediated HSV(1)-tk gene transfer in a rat model of ovarian tumor via intra-arterial route].

OBJECTIVE: To observe the gene and protein expression of herpes simplex virus type I-thymidine kinase (HSV(1)-tk) in the ovarian tumor tissues and other organs after arterial infusion of HSV(1)-tk gene mediated by GE7 delivery system. METHODS: GE7-polylysine/pCMV-HSV(1)-tk/polylysine-HA20 complexes were constructed. Nine rats with induced ovarian tumor were divided into 3 groups, injecting the 4-element complexes or saline buffer through the ovarian artery and complexes through the tail vein, respectively. The ovarian tumors, hearts, livers, spleens, lungs and kidneys were obtained at 72 hours after injection. RT-PCR and Western Blot were preceeded to determine the expression of HSV(1)-tk gene and protein in the tumor tissues and other organs. RESULTS: In the group of arterial injection with 4-element complexes, the HSV(1)-tk gene and protein were expressed strongly in the tumor tissues, while little or none was detected in other organs. In the group of arterial injection with saline buffer, no HSV(1)-tk gene and protein was detected in both tumor tissues and other organs. In the group of tail vein injection, none was detected in tumor tissues and only little was found in the livers, spleens, lungs and kidneys. CONCLUSION: High target and gene transfer rates can be obtained when HSV(1)-tk gene is transferred via the artery route mediated by GE7 delivery system. HSV(1)-tk protein can be expressed after the gene transfer. The results may provide a new strategy for target killing of HSV(1)-tk/GCV system in ovarian tumors.

Enhanced efficiency and specificity of ovarian cancer gene therapy in rats with a novel nonviral gene delivery system (GE7) via intraovarian artery perfusion approach.

Transfer of the herpes simplex virus type I-thymidine kinase gene, followed by the administration of ganciclovir (HSV1-tk/GCV) into ovarian cancer-derived cell line either in vitro or transplanted into nude mice has been shown to provide a potential strategy for the gene therapy of ovarian cancer. We investigated the antitumor effects of HSV1-tk/GCV strategy with a chemically induced rat ovarian cancer model and a tumor-selective gene delivery by a novel nonviral gene delivery system (GE7) through the ovarian artery and tail vein. We demonstrated the expression of a reporter gene, beta-gal gene, as well as HSV1-tk gene in tumors and other organs, evaluated the overall antitumor effects after the GCV treatment and analyzed the tumor cell cycle phase distribution. Via the ovarian artery route, the expressions of beta-gal and HSV1-tk in tumors were significantly stronger than those expressed in such organs as the hearts, livers, spleens, lungs and kidneys. However, no beta-gal and HSV1-tk were detected in the tumor tissues when administrated via the tail vein, and little was found in other organs. The cell cycle analysis showed that the total S-phase of tumor cells in the test intra-arterial treatment group was considerably higher than that of the controls. The weight of the tumor tissues in the group treated by the intra-arterial route (4.06+/-2.12 g) was much less than the group treated intravenously (18.25+/-8.34 g) (P<.01). These findings indicated that the administration of GE7/HSV1-tk complex via the ovarian artery route could be a promising avenue of future human ovarian cancer treatment.

[Reporter genes transfer into human squamous cell carcinoma of larynx factor receptor mediated non-viral GE7 polypeptide delivery system with a new epidermal growth].

OBJECTIVE: To evaluate the efficiency of marker gene and reporter gene transfection into human squamous cell carcinoma of larynx implanted in nude mice with a new EGFR mediated non-viral polypeptide gene delivery system. METHODS: Labeled streptavidin biotin (LSAB) was applied to examine over-expression of epidermal growth factor receptor (EGFR) on the squamous cell carcinoma of larynx. The complex of marker gene or reporter gene and gene delivery system was prepared and subsequently inoculated with Hep 2 cells or injected into laryngeal carcinoma implanted on nude mice. RESULTS: Over-expression of EGFR was observed on inoculated Hep 2 cells and on 65% of laryngeal carcinoma specimen examined (15/23). Positive staining was located on the surface of the cells and some of them in the cytoplasma. Green fluorescence was observed on Hep 2 cells under fluorescent microscope 48 hrs after PEGFP-C1 gene transfection and became the strongest 72 hrs after transfection. The rate of transfection was 80% (78/97). Blue staining was noticed 12 hrs after beta-gal gene transfer and it became more remarkable 24 hrs after gene transfection with X-gal staining on the implanted human laryngeal carcinoma on nude mice. CONCLUSIONS: Squamous cell carcinoma of head and neck over-expressed EGFR and a non-viral GE7 polypeptide gene delivery system could transfer exogenous genes into laryngeal carcinoma cells and tissues with high efficiency and targeting both in vitro and in vivo suggesting that GE7 would be applicable as a new targeted, high efficient gene delivery system to the gene therapy of squamous cell carcinoma of head and neck.

[Study of GE7-transferring system mediated beta-galactosidase gene transfer in a rat model of ovarian tumor by intraarterial route].

OBJECTIVE: To investigate the efficiency and targeting of the GE7 system mediated gene transfer in the chemically induced ovarian tumor by intraarterial route. METHODS: Animal models were chemically induced by 7,12-dimethylbenz[a]anthracene (DMBA). GE7-polylysine/beta-galactosidase (beta-gal)/polylysine-HA20 complexes were constructed. Fifteen rats with induced ovarian tumor were divided into three groups, the complexes were injected through ovarian artery and tail vein, respectively. The tumor, heart, liver, spleen, lung and kidney were obtained at 72 h. X-gal staining was used to check expression of beta-gal. RESULTS: beta-gal was expressed strongly and well-distributed in tumor in the first group, and stained blue in the liver, spleen, lung and kidney, but much weaker than that of tumor. In the second group, beta-gal was expressed in the tumor, and weakly expressed in the liver, none was detected in the other organs. In the third group beta-gal was detected in the lung slightly, none was detected in the tumor and other organs. CONCLUSIONS: When GE7 complexes were administrated through ovarian artery, the introduced gene expressed preferentially in ovary. This result was the basis of intraarterial administration of therapeutic gene to treat ovarian cancer.

Systemic genetic transfer of p21WAF-1 and GM-CSF utilizing of a novel oligopeptide-based EGF receptor targeting polyplex.

Based on the fact that aberrant overexpression of some growth factor receptors was observed in a variety of human cancer cells, a novel nonviral gene delivery system GE7, which contains a 16-amino-acid ligand for identifying EGF receptor was constructed for tumor-targeted gene therapy. Intravenous administration of GE7 system revealed that it has the ability to target beta-galactosidase (beta-gal) reporter gene into murine hepatoma (Hepa) cells. Owing to the limited antitumor effects elicited by a single-gene transfer, recent efforts to treat malignancy using combined gene therapy have been accomplished with varying degrees of success. In this study, the human cyclin-dependent kinase inhibitor gene p21(WAF-1) and the murine cytokine gene granulocyte-macrophage colony-stimulating factor (GM-CSF) were used simultaneously for in vivo gene therapy through systemic injection of the EGF R targeted GE7/DNA complex into murine hepatoma-bearing mice. The results demonstrated that combined administration of p21(WAF-1) and GM-CSF could remarkably inhibit the growth of subcutaneously transplanted hepatoma Hepa cells, and significantly increase the survival rate of tumor-bearing mice. The activities of natural killer (NK) cells and specific cytotoxic T lymphocytes (CTL) were clearly enhanced after combined gene therapy. In vitro experiments showed that p21(WAF-1) gene transfer exhibited a suppressive function on the growth of Hepa cells and the expression of H-2K(b) and B7-1 molecules on Hepa cells increased significantly after combined genes delivery. All these results suggested that the GE7 system was able to target therapeutic genes efficiently to cancer cells, which showed high EGF R expression. The cotransfer of p21(WAF-1) and GM-CSF genes apparently inhibited the growth of tumors through (a) the arrest of tumor cell growth and (b) the enhancement of systemic antitumor immunity.

A novel HBV antisense RNA gene delivery system targeting hepatocellular carcinoma.

AIM: To construct a novel HBV antisense RNA delivery system targeting hapatocellular carcinoma and study its inhibitory effect in vitro and in vivo. METHODS: GE7,a 16-peptide specific to EGFR, and HA20,a homologue of N-terminus of haemagglutinin of influenza viral envelope protein, were synthesized and conjugated with polylysin. The above conjugates were organized into the 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. Hepatocelluar carcinoma HepG2.2.15 cells was used to assay the in vitro inhibition of the complex on HBV. Expression of HBV antigen was assayed by ELISA. BALB/c nude mice bearing HepG2.2.15 cells were injected with AFP-enhancing 4-element complex. The expression of HBV antisense RNA was examined by RT-PCR and the size of tumor in nude mice were measured. RESULTS: The AFP-enhancing 4-element complex was constructed and DNA was completely trapped at the slot with no DNA migration when the ratio of polypeptide to plasmid was 1:1. The expression of HBsAg and HBeAg of HepG2.2.15 cells was greatly decreased after being transfected by AFP-enhancing 4-element complex. The inhibitory rates were 33.4 % and 58.5 % respectively. RT-PCR showed HBV antisense RNA expressed specifically in liver tumor cells of tumor-bearing nude mice. After 4 injections of AFP-enhancing 4-element complex containing 0.2 micro g DNA, the diameter of the tumor was 0.995 cm+/-0.35, which was significantly smaller than that of the control groups(2.215 cm+/-0.25, P<0.05). CONCLUSION: AFP-enhancing 4-element complex could deliver HBV antisense RNA targeting on hepatocarcinoma and inhibit both HBV and liver tumor cells in vitro and in vivo.

[In vitro experimental study of gene therapy for ovarian cancer with thymidine kinase gene of herpes simplex virus mediated by a non-viral GE7 delivery system].

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 beta-galactosidase (beta-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.

[Expression of histone-based fusion protein HNHG in E.coli].

Histone H1 contributes to condense nucleosome into super-structure during the transformation of chromatin into chromosome. It is shown in this rep or t that the fusion protein HNHG with the core of C-terminus of histone H1(0) expressed in BL21 (DE3) could also condense the plasmid DNA, just as histones did in nucleus. Under electron microscope, plasmid DNA condensed and supercoiled after t he addition of HNHG, in contrast to plasmid DNA control. This specific ability of the fusion protein HNHG of binding and condensing plasmids could be utilized to construct novel exogenous gene delivery systems. HNHG would be a promising candidate for gene delivery.