OBJECTIVETo study the cytotoxic activity against tumor cells and cytokines production of spleen cells induced in vitro by murine 4-1BBL gene transfected Hepa1-6.

METHODSThe eukaryotic expression vector pCDNA3.1(+)-m4-1BBL was transfected into murine hepatocellular carcinoma cell line Hepa1-6 by Liposomes. Then the transfected cells were selected in medium containing G418 (400 - 800 micro g/ml) and termed as Hepa1-6-m4-1BBL. The TCV-m4-1BBL was obtained by treating them with mitomycin (MMC). Cocultivation TCV with syngeneic murine spleen cells, then the lymphocytes were tested for cytotoxic activity against Hepa1-6-wt cells and the supernatants were harvested for detecting the cytokines (IL-2, TNF-alpha and GM-CSF).

RESULTSHepa1-6-m4-1BBL cells expressed 4-1BBL protein with highest cell surface level. The 4-1BBL mRNA could still be detected in the cells when cultured 48 h after treated with MMC (80 mg/L). Comparing with TCV-Hepa1-6, the tumor cell vaccine derived from Hepa1-6-m4-1BBL (TCV-m4-1BBL) could induce a more efficient cytotoxic activity of syngeneic murine lymphocyte against its parental tumor cell Hepa1-6 (P < 0.05), but not against non-parental tumor cell H22 and NIH3T3. Higher levels of IL-2, TNF-alpha and GM-CSF were released by the splencytes after stimulated by TCV-m4-1BBL.

CONCLUSIONSThese results suggest the expression of m4-1BBL by tumor cells is effective in inducing antitumor immune responses.

4-1BB Ligand ; Animals ; Cancer Vaccines ; immunology ; Female ; In Vitro Techniques ; Liver Neoplasms, Experimental ; immunology ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Necrosis Factors ; genetics ; physiology

OBJECTIVETo observe the in vivo antitumor activity of murine liver tumor vaccine expressing MIP-1alpha mediated by recombinant adenoviral vector.

METHODSThe infection efficacy was measured by GFP expression 48 hours after infection of Hepa1-6, and the number of cells was counted daily for 14 days. 5 x 10(6) modified Hepa1-6 cells were inoculated subcutaneously to C57BL/6 mice and the tumor-free animals were rechallenged by 2 x 10(6) wild-type Hepa1-6 cells or syngenic EL4 cells four weeks later. The tumor volume was measured twice a week.

RESULTSAdenoviral vectors could efficiently infect Hepa1-6 cells in vitro, and the in vitro growth rate of AdmMIP-1alpha modified Hepa1-6 cells was not affected; however the in vivo tumorigenicity was significantly decreased, compared with that of control vector modified Hepa1-6. Rechallenge of the tumor-free mice four weeks after administration of AdmMIP-1alpha with the parental Hepa1-6 cells resulted in significant inhibition of tumor growth, but there was no significant difference when rechallenged with EL4.

CONCLUSIONSThe liver cancer cells expressing mMIP-1alpha mediated by recombinant adenoviral vector decrease tumorigenicity and elicit specific immunological protection, and could be used as an effective liver tumor vaccine.

Adenoviridae ; genetics ; Animals ; Cancer Vaccines ; immunology ; Chemokine CCL3 ; Chemokine CCL4 ; Genetic Therapy ; Liver Neoplasms, Experimental ; therapy ; Macrophage Inflammatory Proteins ; genetics ; Mice ; Mice, Inbred C57BL ; Vaccines, Synthetic ; immunology

Animals ; COS Cells ; Female ; Genetic Therapy ; Interleukin-12 ; genetics ; Liver Neoplasms, Experimental ; immunology ; therapy ; Mice ; Mice, Inbred BALB C ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo study the immunoprotective effect of IL-2 and B7-1 gene co-transfected liver cancer vaccine on hepatocarcinogenesis in mice.

METHODSThe murine liver cancer cell strain Hepal-6 was transfected with IL-2 and/or B7-1 gene via recombinant adenovirus vectors and the liver cancer vaccines were prepared. C57BL/6 mice were immunized with the vaccines and challenged with the parental Hepal-6 cells afterwards. The immunoprotection was investigated and the reactive T cell line was assayed.

RESULTSThe effect of the Hep6-IL2/B7 vaccine on the onset of tumor formation was the strongest. The media survival time of the mice was the longest (68 days, P<0.05) and the implanted tumor was the smallest (P<0.05). The effect of single IL-2 or B7-1 gene-transfected vaccine was next to the co-transfected gene group with the mean survival time being 59 and 54 days, respectively. The mean survival time of wild or BGFP gene modified vaccine immunized group was 51 and 48 days, respectively. The control group all died within 38 days and the implanted tumor was the largest (P<0.05). The cellular immunofunction test and cytotoxicity study showed that the mice immunized with the Hep6-IL2/B7 vaccine gained significantly increased NK, LAK and CTL activity (29.0% +/- 2.5%, 65.0% +/- 2.9%, 83.1% +/- 1.5% respectively, compared with other groups P<0.05).

CONCLUSIONSThe IL-2 and B7-1 gene co-transfected liver cancer vaccines can induce the mice to produce activated and specific CTL against the parental tumor cells, and demonstrate stronger effect on the hepatocarcinogenesis than single gene modified or the regular tumor vaccine. Therefore, the vaccines may become a novel potential therapy for recurrence and metastases of HCC.

Adenoviridae ; genetics ; Animals ; B7-1 Antigen ; genetics ; immunology ; Cancer Vaccines ; administration & dosage ; genetics ; immunology ; Cell Division ; immunology ; Female ; Genetic Vectors ; administration & dosage ; genetics ; immunology ; Humans ; Interleukin-2 ; genetics ; immunology ; Killer Cells, Lymphokine-Activated ; immunology ; Killer Cells, Natural ; immunology ; Liver Neoplasms, Experimental ; immunology ; pathology ; prevention & control ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Survival Analysis ; T-Lymphocytes, Cytotoxic ; immunology ; Time Factors ; Transfection ; Tumor Cells, Cultured

To compare the anti-tumor effects of transmembrane TNF-alpha (TM-TNF) and secreted TNF-alpha (S-TNF) in vivo, mouse fibroblasts NIH3T3 were transfected separately with three types of retrovirus containing wild type TNF-alpha (Wt-TNF), TM-TNF mutant (TM-TNFm), S-TNF mutant (S-TNFm). Southern blot, RT-PCR, FACS and bioassay were used to investigate TNF-alpha gene integration, expression and its biological activity. It was found that both fixed cells and supernatant of NIH3T3/Wt-TNF, the fixed cells of NIH3T3/TM-TNFm and the supernatant of NIH3T3/S-TNFm could express high level of TNF-alpha or its mutants and effectively kill H22 in vitro. The transfected NIH3T3 were separately injected into the mice at the sites of H22 tumor cell inoculation according to a ratio of 5:1 or 1:1 (effector/target cells, E/T) after the third day of H22 challenge, respectively. At the E/T = 5:1, the NIH3T3/TM-TNFm induced the highest tumor regression, while NIH3T3/S-TNFm exerted the strongest tumor depressing effect at the E/T = 1:1 in vivo. No obvious side effects were noted throughout the course of treatment. The results suggest that both TM-TNF and S-TNF could cause tumor regression. The anti-tumor effect of TM-TNF would be more powerful and safe than that of S-TNF at the proper E/T ratio.
3T3 Cells ; Adenoviruses, Human ; genetics ; Animals ; Cytotoxicity, Immunologic ; immunology ; Fibroblasts ; cytology ; immunology ; Liver Neoplasms, Experimental ; immunology ; pathology ; Membrane Proteins ; secretion ; Mice ; Mutation ; Transfection ; Tumor Cells, Cultured ; Tumor Necrosis Factor-alpha ; genetics ; immunology ; secretion

OBJECTIVETo study the effects of 4-1BBL on antitumor immunity induced in vivo by murine 4-1BBL gene transfected Hepa1-6.

METHODSRetrovirus vector was used to transfer the 4-1BBL gene into syngeneic murine heptocellular carcinoma cell line Hepa1-6. The products were termed as Hepa1-6/4-1BBL, and then the TCV4-1BBL was obtained by treating them with mitomycin (MMC). Three models (immunological model, early model, and later model) were established to study the antitumor effects of TCV4-1BBL.

RESULTS(1)In immunological models, the syngeneic mice were completely protected by inoculation with TCV4-1BBL, survived free from tumor for a long period (over 100 days). (2)In early models (7 days after inoculation), Hepa1-6 tumor cells showed strong immunogenicity effects and (3) In later models (14 days after inoculation), they had obvious antitumor effects and most of the tumors were disappeared.

CONCLUSIONSThe antitumor effect against syngeneic murine hepatocellular carcinoma in vivo is obviously enhanced by treating them with TCV4-1BBL

4-1BB Ligand ; Animals ; Cell Division ; immunology ; Female ; Liver Neoplasms, Experimental ; immunology ; pathology ; prevention & control ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; genetics ; immunology ; Transfection ; Tumor Cells, Cultured ; Tumor Necrosis Factor-alpha ; genetics ; immunology

OBJECTIVETo observe the inhibitory effect of dendritic cells (DCs) activated cytotoxicity T lymphocyte (CTL) combined with MAGE-1 nonapeptide on transplanted human hepatocyte carcinoma (HCC) in nude mice.

METHODSA model of HCC transplanted tumor was established by injecting BEL-7402 cell line HCC cells subcutaneously on the back of nude mice. Successful transplantation rate was 73%. Specific CTLs (1 x 10(6)), which were activated by DCs combined with MAGE-1 nonapeptide, were injected into the site of transplanted tumor (group A, n = 5). Another group of 17 mice were treated with same amounts of different kinds of cells, and they were divided into groups B, C, D, E, and F. The growth of tumor was observed, and pathological examination was also done.

RESULTS(1) The activated lymphocytes induced by DCs combined with MAGE-1 nonapeptide could suppress the growth of tumor and reduce the tumor size. In group A, 5/5 mice survived for at least two weeks, while the tumors grew rapidly and the majority of the mice died within two weeks in other groups (groups B, C, D, E, F) (P < 0.01). (2) Extensive necrosis and apoptosis were found in transplanted tumors in group A.

CONCLUSIONSThe DCs combined with MAGE-1 nonapeptide could not only inhibit the growth of HCC, but also result in produce death and apoptosis of HCC, hence preventing tumor metastasis and recurrence. The mechanism underlying tumor immunization resulted from DCs might be enhanced in apoptosis of tumor cells. MAGE-1 nonapeptide combined with DCs might be a potential novel tumor vaccine for the treatment of HCC.

Animals ; Antigens, Neoplasm ; Apoptosis ; Cancer Vaccines ; immunology ; Dendritic Cells ; immunology ; Humans ; Liver Neoplasms, Experimental ; immunology ; pathology ; therapy ; Melanoma-Specific Antigens ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Proteins ; administration & dosage ; genetics ; Neoplasm Transplantation ; T-Lymphocytes, Cytotoxic ; immunology ; Transplantation, Heterologous

PTEN, a dual-specificity phosphatase, exerts its tumor-suppressive effects through the inhibition of cell cycle progression and cell immigration, therefore could be an important candidate for tumor-suppression. As study on prokaryotic expression of PTEN and its anti-tumor functions has not been reported, the present study aims at an efficient expression of functional PTEN in Escherichia coli and the investigation of its tumor-suppression activity. PTEN cDNA cloned in our lab previously was recombined into prokaryotic expression vector pET-44a(+) to construct pET-PTEN (pEP) and pET-Nus-PTEN (pENP). PTEN was fused with 6 x His tag in pEP, and with Nus in pENP, which could be useful for a stable and soluble expression. The recombinant vectors were transformed into both BL21 (DE3) (BL) and Rosetta-gami (DE3) pLysS (RG). The former is a normal expression host while the latter is optimized for expression of eukaryotic genes and folding of target proteins. On the induction of 0.5mmol/L IPTG, 55kD and 118kD specific protein bands were observed, corresponding to His-PTEN and Nus-PTEN fusion proteins, respectively. Western blot analysis showed the recombinant fusion proteins could react with PTEN polyclonal antibody. The recombinant HTEN was expressed both in soluble fraction and inclusion body. Higher expression levels of recombinant PTEN were obtained in BL (His-PTEN: 10.3%; NusA-PTEN: 18.7%), whereas the higher percentages of soluble recombinant proteins were observed in RG (His-PTEN: 4.7%; Nus-PTEN: 6.6%). The obtained recombinant fusion proteins were purified by affinity chromatography and were showed to be homogeneous in SDS-PAGE. In tumor-suppression experiments, His-PTEN was proved to have significant inhibition on growth of mice solid tumor with an inhibitory ratio of 58.76%, and on the proliferation of DU-145 tumor cells with an inhibitory ratio of 46.16%. The cell cycle progression of DU-145 tumor cells was also arrested from G0/G1 to S phase. His-PTEN from RG was proved to have significantly higher tumor-suppression activity than that from BL, indicating that there may be some advantages for eukaryotic genes to be expressed in the former host. This is the report of functional recombinant PTEN expressed in Escherichia coli. Purified His-PTEN was used for immunizing Kunming mice, and ascitic polyclonal antibodies raised against His-PTEN were generated using sarcoma 180 cells. At 1:2000 dilution, the antibodies could interact with PTEN by western blot. The present study has laid a foundation for application of PTEN in cancer therapy.
Animals ; Antibodies, Neoplasm ; biosynthesis ; immunology ; Antineoplastic Agents ; pharmacology ; Escherichia coli ; genetics ; metabolism ; Humans ; Liver Neoplasms, Experimental ; therapy ; Mice ; PTEN Phosphohydrolase ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology

BACKGROUND/AIMS: Immunogene therapy is extensively studied for a therapeutic modality of various cancers. This study was conducted to investigate the efficacy of immunogene therapy using the T-cell costimulatory molecule and human B7-1 (CD80, hB7-1) in an in vivo human hepatocellular carcinoma (HCC) model. METHODS: The stable HCC cell line expressing hB7-1 gene was established using retroviral vector (Huh-7/hB7-1). Of fourteen BALB/c nude mice, 7 were subcutaneously injected with 2 X 10(6) Huh-7/hB7-1 cells, while the other 7 were injected with 2 X 10(6) Huh-7/mock cells as a control group. After the injection, the mice were observed weekly for three months for subcutaneous tumor formation. Assay for natural killer (NK) cell cytotoxicity and serum IFN-gamma was performed at 1 and 2 weeks after inoculation. RESULTS: In BALB/c nude mice inoculated with Huh-7/hB7-1 cells, no tumor growth was observed. BALB/c nude mice inoculated with Huh-7/hB7-1 cells showed significantly increased NK cell activities of splenocytes compared with those with Huh-7/mock cells. Serum IFN-gamma was not measurable at 1 week, but significantly increased at 2 weeks after inoculation to the level of 470 pg/ml in BALB/c nude mice with Huh-7/mock cells and 521 pg/ml in BALB/c nude mice with Huh-7/hB7-1. CONCLUSIONS: Our results demonstrate the in vivo anti-tumor immunity and NK cell activation by transfer of hB7-1 gene into human HCC in xenogeneic BALB/c nude mice model. This approach may provide a tool for the development of immunogene therapies against human malignant tumors.
Animals ; Antigens, CD80/*genetics ; Cytotoxicity, Immunologic ; Gene Transfer Techniques ; Humans ; Interferon-gamma/metabolism ; Killer Cells, Natural/*immunology ; Liver Neoplasms, Experimental/genetics/*immunology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation

OBJECTIVETo investigate the effects of immunization with fusions of dendritic cells and H22 cells on tumor-bearing mice and their possible mechanisms.

METHODSFusion cells of DC and H22 cells were prepared with polyethylene glycol (PEG). Expression of MHC and costimulatory molecules by dendritomas were determined by FACs. To study the antitumor immune preventative and therapeutic effects, fusions were subcutaneously injected into tumor-bearing mice. The cytotoxic T lymphocyte (CTL) activity was determined by LDH method, the expression of TNF-a and IFN-g in tumors were assayed by RT-PCR.

RESULTSThe data showed that the hybridomas of DC and H22 cells acquired both DC and H22 cell phenotypes. Immunization of BALB/C mice with DC/H22 fusions induced potent CTL activity (mean CTL activity=0.624+/-0.024, compared with DC + H22, DC, H22 groups, F = 65.46) and a protective immunity against a high dose of H22 tumor challenge. After treatment with hybridomas, the survival time of tumor-bearing mice was greatly extended (x2=18.45). The expression levels of TNF-a and IFN-g mRNA were remarkably increased (TNF-a, F = 47.84; IFN-g, F = 37.23).

CONCLUSIONSThe hybridomas of DC and H22 cells could induce effective antitumor immune responses and may have a useful potential in prevention and management of the recurrences and metastases of HCC.

Animals ; Cancer Vaccines ; immunology ; Carcinoma, Hepatocellular ; genetics ; immunology ; Cell Fusion ; Dendritic Cells ; immunology ; Female ; Hybridomas ; Immunization ; Interferon-gamma ; biosynthesis ; genetics ; Liver Neoplasms, Experimental ; genetics ; immunology ; prevention & control ; Mice ; Mice, Inbred BALB C ; Polyethylene Glycols ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics ; Vaccination