Gene therapy using adenovirus-mediated full-length anti-HER-2 antibody for HER-2 overexpression cancers.

PURPOSE: Therapeutic monoclonal antibody is increasingly applied in many clinical applications, although complicated technologies and high cost still limit their wide applications. To obtain the sustained serum antibody concentration with one single injection and lower the cost of antibody protein therapy, an adenovirus-mediated full-length antibody gene therapy was developed. EXPERIMENTAL DESIGN: Full-length antibody light-chain and heavy-chain sequences were linked with internal ribosome entry site and constructed into adenoviral vector under the control of cytomegalovirus promoter. Antibody expression in vitro and in vivo were tested with ELISA, and its antitumor efficacy was evaluated in SKOV-3-inoculated nude mice. RESULTS: Ad5-TAb-generated anti-HER-2 antibody presented the similar binding specificity with commercial trastuzumab. A single i.v. injection of 2 x 10(9) plaque-forming units of Ad5-TAb per mouse resulted in not only a sustained over 40 microg/mL serum antibody level for at least 4 weeks but also significant tumor elimination in the ovarian cancer SKOV-3-inoculated nude mice. CONCLUSIONS: An in vivo full-length antibody gene delivery system allows continuous production of a full-length antibody at high concentration after a single administration. Bioactive antibody macromolecules can be generated via gene transfer in vivo. All the data suggest that this novel adenovirus-mediated antibody gene delivery can be used for the exploitation of antibodies, without being hampered by the sophisticated antibody manufacture techniques and high cost, and, furthermore, can shorten the duration and reduce the expense of antibody developments.

Immune gene-viral therapy with triplex efficacy mediated by oncolytic adenovirus carrying an interferon-gamma gene yields efficient antitumor activity in immunodeficient and immunocompetent mice.

Among numerous gene therapeutic strategies for cancer treatment, gene transfer by conditionally replicative adenovirus (CRAd) of interferon-gamma (IFN-gamma) may be useful because of the possibility that it will yield IFN-gamma-mediated antiangiogenesis, immune responses, and CRAd-mediated oncolysis. In this study, we constructed a human TERT promoter-mediated oncolytic adenovirus targeting telomerase-positive cancers and armed with a mouse or human IFN-gamma gene to generate novel immune gene-viral therapeutic systems, CNHK300-mIFN-gamma and CNHK300-hIFN-gamma, respectively. The systems can specifically target, replicate in, and lyse cancer cells, while sparing normal cells. The advantage of these systems is that the number of transgene copies and their expression increase markedly via viral replication within infected cancer cells, and replicated viral progeny can then infect additional cancer cells within the tumor mass. CNHK300-mIFN-gamma induced regression of xenografts in liver cancer models in both immunodeficient and immunocompetent mice by triplex mechanisms including selective oncolysis, antiangiogenesis, and immune responses. We conclude that combining immune gene therapy and oncolytic virotherapy can enhance antitumor efficacy as a result of synergism between CRAd oncolysis and transgene composite antitumor responses.

[CNHK200-hA-a gene-viral therapeutic system and its antitumor effect on lung cancer].

OBJECTIVE: To develop a novel vector system, which combines the advantages of the gene therapy, antiangiogenic therapy and virus therapy, and to observe its effect on lung cancer. METHODS: Human angiostatin gene hA(k1-5) was inserted into the genome of the replicative virus specific for the tumor cells by virus recombination technology. The expression of hA(k1-5), its effect on tumor growth in vitro and in vivo were studied. RESULTS: A new kind of gene-viral vector system, designated as CNHK200-hA(k1-5), in which the E1b55 000 gene was deleted but the E1a gene of adenovirus preserved, was constructed. The novel vector system possessed the same property as the replicative virus ONYX-015, which replicates in p53- tumor cells but not in normal cells, thus specifically kills tumor cells. In vitro, CNHK200-hA and Ad-hA both could kill A549 tumor cells but the latter needed 100 times more MOI to achieve the same amplitude of cell killing. In vivo, the therapeutic effect of CNHK200-hA on human lung cancer A549 xenograft in nude mice was significantly better than that of Ad-hA and that of tumor-replicative virus ONYX-015. CONCLUSION: CNHK200-hA(k1-5), a novel vector is constructed in which the angiostatin gene is inserted into the genome of the replicative adenovirus cytotoxic to p53-negative tumor cells. It has the advantages of specific tumor targeting, high level gene expression in tumor cells, and potent tumoricidal activity.

[Construction and analysis of in vitro expression of adenovirus/adeno-associated hybrid virus containing the fusion gene of human beta-endorphin].

The fusion gene of human beta-endorphin was cloned into the shuttle plasmid pDC312-AAVEE with the method of molecular bilology. The latter and genomic plasmids were cotransfected into HEK293 to package the Adenovirus/Adeno-associated hybrid virus containing fusion gene of human beta-endorphin. The hybrid virus was identified with the method of PCR. The titer of proliferated virus, after purified, was determined by TCID50. The expression of transgene was studied after the hybrid virus infected the cultured cells, through testing the concentration of expressed product in the culture liquid by ELISA. It was identified that the sequence of fusion gene of human beta-endorphin was correctly inserted into the genome of hybrid virus, and not contaminated by wild type virus. The titer of Ad/AAV-EE is 1.29 x 10(10) PFU/mL after purification. The ascending trend of transgene expression was observed from the 1st to the 14th day, and the protein concentration reached 3141 pg/mL at the 14th day.

Potent antitumor efficacy of an E1B 55kDa-deficient adenovirus carrying murine endostatin in hepatocellular carcinoma.

Data from clinical trails have shown that the antitumoral effect of ONYX-015, an E1B 55kDa-deficient adenovirus, as monotherapy is insufficient. To enhance its efficiency, CNHK200-mE, another E1B 55kDa-deficient adenovirus armed with a mouse endostatin gene was constructed and its antitumoral activities against hepatocellular carcinoma (HCC) in vitro and in vivo were investigated. The selective replication and cytotoxicity of CNHK200-mE in Hep3B and HepGII cells independent of p53 status were confirmed via TCID50 and 3-(4,5dimetylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assays. Potent tumor growth suppression on SMMC-7721 xenografts in nude mice was observed and a synergistic effect of the carrier virus and the therapeutic gene was suggested. Moreover, in comparison with the nonreplicative adenovirus carrying the same therapeutic gene, amplified transgene expression of mouse endostatin in vitro and in vivo were confirmed by Western blotting and ELISA assay. The effective angiogenesis inhibition and replication of CNHK200-mE in nude mice xenografts were demonstrated by immunohistochemistry. In conclusion, the recombinant adenovirus CNHK200-mE is a replication-competent oncolytic virus mediating high expression of therapeutic gene. Because CNHK200-mE is capable of replicating in and lysing HCC cells selectively with effective tumor growth suppression and antiangiogenic activity on HCC xenografts in nude mice, it holds good potential for the treatment of HCC.

[Gene therapy for ovarian cancers by adenovirus-mediated complete antibody gene].

OBJECTIVE: To study the feasibility of adenoviral transduction of Herceptin complete antibody gene and its effect on Her2 over-expressing cancer. METHODS: The genes of VH and VL from the monoclonal antibody Herceptin were cloned into the genome of replication-defective adenovirus by viral recombination technology to produce the recombinant adenovirus Ad-SG-Her. Normal human liver cells of the line L-02 were transfected with Ad-SG-Her and ELISA was used to detect the expression of Herceptin antibody 3 and 7 days after. Forty BALB/c nude mice were inoculated with Her2 high-expressing oophoroma cells of SK-OV-3 line and were randomized into 4 equal groups: group A injected with Ad-SG-Her at the dosage of: 2 x 10(9) plaque forming unit (pfu) through the caudal vein, group B injected with Ad-SG-Her at the dosage of 1 x 10(9) pfu, group C injected with Ad-SG-Her at the dosage of 5 x 10(8) pfu, and control group. On the days 3, 7, 10, 14, 21, 28, and 35 after the injection of virus, the antibody expression in the serum was measured by ELISA and the size of tumor was measured vernier caliper. Western blot and IFA was used to detect the specificity for Her2-overexpressing ovarian cancer cell lines SK-OV-3 and the integrity of complete antibody. Anti-tumor effects were also observed in nude mice bearing SK-OV-3 tumors. RESULTS: The constructed recombinant adenovirus Ad-SG-Her could express Herceptin efficiently both in vitro and in vivo. The biological activity of the expressed antibody was similar to that of the commercial Herceptin as shown by Western blotting, IFA, and ELISA. Herceptin expression of Ad-SG-Her was detected since day 3 after treatment in the groups A, B, and C and reached the peak on days 7 - 10. The expression lasted for four weeks or so. The expression level was significantly different between group A and the groups B and C (all P < 0.05), however, without a significant difference between the group B and group C. The antibody expression of group A might increase to 103.5 micro g/ml, high enough to inhibit tumor growth and induce tumor cell apoptosis. The antibody expression of the group B was below 40 micro g/ml, and that of the group C was below 30 micro g/ml. Furthermore the expressed antibody doses were statistically significantly different at different time points. Almost no tumor growth was seen in the group A during the observation period in comparison with the groups B and C and the control group (all P < 0.05). The tumor growth was almost not influenced in the group B and C and the control group. CONCLUSION: Ad-SG-Her efficiently expresses humanized complete Herceptin with effective bioactivity and induces long-term stable expression both in vitro and in vivo. The system may serve as a new antitumoral gene therapy strategy in antibody field.

Effective gene-viral therapy for telomerase-positive cancers by selective replicative-competent adenovirus combining with endostatin gene.

Gene-viral therapy, which uses replication-selective transgene-expressing viruses to manage tumors, can exploit the virtues of gene therapy and virotherapy and overcome the limitations of conventional gene therapy. Using a human telomerase reverse transcriptase-targeted replicative adenovirus as an antiangiogenic gene transfer vector to target new angiogenesis and making use of its unrestrained proliferation are completely new concepts in tumor management. CNHK300-mE is a selective replication transgene-expressing adenovirus constructed to carry mouse endostatin gene therapeutically. Infection with CNHK300-mE was associated with selective replication of the adenovirus and production of mouse endostatin in telomerase-positive cancer cells. Endostatin secreted from a human gastric cell line, SGC-7901, infected with CNHK300-mE was significantly higher than that infected with nonreplicative adenovirus Ad-mE in vitro (800 +/- 94.7 ng/ml versus 132.9 +/- 9.9 ng/ml) and in vivo (610 +/- 42 ng/ml versus 126 +/- 13 ng/ml). Embryonic chorioallantoic membrane assay showed that the mouse endostatin secreted by CNHK300-mE inhibited angiogenesis efficiently and also induced distortion of pre-existing vasculature. CNHK300-mE exhibited a superior suppression of xenografts in nude mice compared with CNHK300 and Ad-mE. In summary, we provided a more efficient gene-viral therapy strategy by combining oncolysis with antiangiogenesis.

[The specific cytotoxic effect of tumor infiltrating lymphocytes transfected with chimeric T cell receptor on cells which express KDR].

OBJECTIVE: To investigate the specific cytotoxity of tumor infiltrating lymphocytes (TIL) transfected with chimeric T cell receptor (CTCR) on cells which express KDR. METHODS: A recombinant retroviral plasmid (pMSCVneo-Vhgamma) was constructed by cloning VEGF121-hinger-FcRgamma (Vhgamma) into retroviral vector pMSCVneo. After packaging by PT67, the virus with high titer was used to infect TIL isolated from liver cancer tissues, and then MSCVneo-Vhgamma-TIL was generated. TIL infected with MSCVneo was used as a control. The cytotoxicty of the transgenic TIL on NIH3T3 and HepG2 expressing no KDR and on ECV304 and A375 expressing KDR was detected with MTT colorimetric assay. RESULTS: The sequences of VEGF121 and hinger-FcRgamma were different from those reported, but the deduced amino sequences were identical to the reported ones. The cytotoxity of TIL infected with MSCVneo on target cell was similar to that of the control TIL; both only had mild cytotoxity on cancer cell line. No significant cytotoxity was found in TIL infected with MSCVneo-cTCR on NIH3T3, but its cytotoxity on ECV304 was significant. The cytotoxity on HepG2 was similar to that of MSCVneo-TIL and uninfected TIL, but cytotoxity on A375 was significantly higher. CONCLUSION: Chimeric T cell receptor permanently grafts TIL cell with predefined new specificity. TIL expressing Vhgamma can selectively recognize and kill vascular endothelial cell and tumor cells which express VEGF receptor KDR.

[In vitro gene therapy of hepatocellular carcinoma using replication-defective and tumor-specific replication-competent adenovirus carrying interleukin-12 gene].

OBJECTIVE: To evaluate the therapeutic effect and the expression level of a tumor-specific replication-competent adenovirus and a replication-defective adenovirus expression mouse recombinant IL-12 (mIL-12) gene on hepatocellular carcinoma (HCC) in vitro. METHODS: The cytotoxicity of replication-competent adenovirus with E1B-55 000 attenuated CNHK200-mIL12 and ONYX-015 (dl1520), and replication-defective adenovirus Adv-mIL12 were evaluated by MTT and replication assay in two HCC cell lines (HepG2 and Hep3B) and human normal hepatocyte line (LO2). Western blot and ELISA were used to determine the expression level of mIL-12. RESULTS: CNHK200-mIL12 replicated in HepG2 and Hep3B with an increase of 3,160-fold and 630-fold respectively in 96 h post-infection. CNHK200-mIL12 could kill HepG2 and Hep3B cells at a very low MOI (Multiplicity of Infection) and in short time course (HepG2:MOI = 0.2, on day 4; Hep3B:MOI = 0.005, on day 2), while it had no significant effect on LO2. Furthermore, the expressing level of mIL-12 in CNHK200-mIL12 treated HCC cell lines was much higher than that in Adv-mIL12 treated one (HepG2 101-fold, Hep3B 20-fold respectively). CONCLUSION: Replication-competent adenovirus is more effective than replication-defective adenovirus in both cytotoxicity and efficiency of gene transfer in HCC, and holds great promise in the area of HCC therapy.

[Injection of NKG5SV gene to inhibit growth and metastasis of hepatocellular carcinoma].

OBJECTIVE: To study the injection of NKG5SV gene to inhibit growth and metastasis of hepatocellular carcinoma (HCC). METHODS: NKG5SV gene was inserted into retroviral vector pLXSN by normal methods. LacZ gene was used as control. LCI-D20 tumor together with saline, pLXSN-LacZ DNA or pLXSN-NKG5SV was subcutaneously inoculated to the nude mice. Tumor formation rate and tumor size were noted 35 days after inoculation. LCI-D20 tumor was inoculated subcutaneously. Saline, pLXSN-LacZ DNA or pLXSN-NKG5SV was intratumorally injected respectively 10 days after inoculation. Tumor growth was observed 35 days after inoculation. Liver cancer was resected 22 days after intrahepatic inoculation. Saline, pLXSN-LacZ DNA or pLXSN-NKG5SV was respectively injected at incisal margin or intraspleen. Mice were killed 35 days after inoculation to observe tumor recurrence at incisal margin, intrahepatic metastasis and extrahepatic metastasis. RESULTS: Tumor formation rate and tumor diameter(cm) were 1.76 +/- 0.11, 1.51 +/- 0.34, 0.33 +/- 0.04 in the control group, LacZ group, NKG5SV group respectively when tumor and different cDNA were inoculated together. Tumor diameter(cm) and weight(g) were 0.87 +/- 0.08, 0.83 +/- 0.05, 0.26 +/- 0.04; 0.43 +/- 0.06, 0.38 +/- 0.04, 0.08 +/- 0.06 in the control group, LacZ group, NKG5SV group respectively when different cDNA were injected into the LCI-D20 tumor. Sites with extrahepatic metastasis nidi, incisal margin recurrence tumor size(cm), intrahepatic metastasis nidi, metastasis involved hepatic lobes in the control group, LacZ group, NKG5SV group were 4.25 +/- 1.48, 4.25 +/- 1.04, 0.63 +/- 0.51; 1.51 +/- 0.27, 1.35 +/- 0.17, 0.81 +/- 0.17; 2.50 +/- 1.41, 2.38 +/- 1.06, 1.25 +/- 0.71; 2.13 +/- 0.99, 2.00 +/- 0.75, 1.38 +/- 0.74 respectively when NK cells were injected at incise margin. They were 4.38 +/- 1.85, 4.25 +/- 1.48, 1.00 +/- 0.75; 1.13 +/- 0.23, 0.97 +/- 0.29, 0.76 +/- 0.16; 2.50 +/- 1.41, 2.05 +/- 1.12, 0; 2.13 +/- 0.83, 1.75 +/- 0.88, 0 respectively when NK cell were injected intrasplenicly. CONCLUSIONS: NKG5SV gene can inhibit HCC growth and postoperative metastasis and recurrence.

Gene-viral vectors: a promising way to target tumor cells and express anticancer genes simultaneously.

OBJECTIVE: To develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies. METHODS: Using recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively. RESULTS: A new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy. CONCLUSIONS: Gene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.

[Development of gene-viral vector and its anti-tumor effect, a primary study].

OBJECTIVE: To develop a new kind of vector system, named as gene-viral vector, which combines the advantages of the gene therapy and virus therapy. METHOD: An anti-tumor gene was inserted into the genome of the replicative virus specific for the tumor cells by virus recombination technology. The killing effect, report gene expression of the green fluorescence protein, expression of the anti-tumor gene of mouse IL12, and the replication of the virus were observed respectively by cell pathology, fluorescence microscopy, ELISA and electron microscopy. RESULTS: A new kind of gene-viral vector system, in which the E1b-55 000 gene is deleted but the E1a gene of adenovirus is preserved, was constructed. The vector system possessed the same characteristics as the replicative virus ONYX-015, replication and proliferation in the tumor cells but not in the normal cells, thus specifically killing the tumor cells. Besides, it carried many kinds of anti-tumor genes. When carrying the report gene of the green fluorescence protein it made the expression of this gene in tumor cells far more effectively than the adenovirus vector employed in the traditional gene therapy did. However in the normal cells the expression of green fluorescence protein caused by this vector system was as little as or even less than that by the traditional adenovirus system. The similar result was also observed in the experiments of this vector system carrying the anti-tumor gene, gene of mouse IL12. The replication and proliferation of the virus carrying the gene of mouse IL12 in the tumor cells were confirmed by electron microscopy. CONCLUSION: Gene-viral vector is a new kind of vector in which the anti-tumor gene is inserted into the genome of the replicative virus specific for the tumor cells. It increases the expression of the anti-tumor gene by hundreds even tens of thousand times. It posseses all the advantages of gene therapy and virus therapy, thus further enhancing the curative effect and it overcomes such disadvantages as low transfer rate, low expression, lack of target tropism and low anti-tumor activity. It will become one of the most promising means in tumor treatment.