Adenovirus-mediated transfer of HPV 16 E6/E7 antisense RNA combined with cisplatin inhibits cellular growth and induces apoptosis in HPV-positive head and neck cancer cells.

Human papillomavirus (HPV) infection has been identified as an etiologic factor of head and neck cancers (HNCs). We explored the potential use of antisense HPV RNA transcripts for gene therapy and its effect in combination with cisplatin (CDDP) for HPV-positive HNCs. We introduced the antisense RNA transcripts of the E6 and E7 genes of HPV type 16 into UM-SCC-47 cells harboring HPV 16 and YCU-T892 cells that were HPV-negative using a recombinant adenoviral vector, Ad-E6/E7-AS. We then analyzed the effects of the introduction of Ad-E7-AS on cell and tumor growth and the synergistic effect with CDDP in vitro and in vivo. After infection of Ad-E6/E7-AS, the cellular growth of UM-SCC-47 cells were suppressed, but not that of YCU-T892 cells. E7 protein expression was suppressed, and p53 and pRb protein expression increased after infection of Ad-E7-AS. Cell growth and tumorigenicity were greatly suppressed in combination with CDDP compared with Ad-E7-AS or CDDP treatment alone in vitro. Ad-E7-AS combined with CDDP treatment significantly reduced the volumes of established subcutaneous tumors. Transfection with HPV 16 E7 antisense RNA combined with CDDP treatment might be a potentially useful approach to the therapy of HPV 16-positive HNC.

A clinical protocol to inhibit the HGF/c-Met pathway for malignant mesothelioma with an intrapleural injection of adenoviruses expressing the NK4 gene.

BACKGROUND: The hepatocyte growth factor (HGF)/c-Met signal pathway is up-regulated in human mesothelioma and suppression of the HGF/c-Met signaling with a competitive inhibitor, NK4 homologous to HGF in the structure, produced anti-tumor effects to mesothelioma in a preclinical study. Mesothelioma is highly resistant to a number of chemotherapeutic agents but distant metastasis to extra-thoracic organs is relatively infrequent until the late stage. METHODS/DESIGN: We planned to conduct a clinical study of gene therapy with adenoviruses expressing the NK4 gene (Ad-NK4) to control the local tumor growth. The study is designed to inject Ad-NK4 into the intrapleural cavity with a dose escalation manner from 10(10) to 10(12) virus particles per patient and to examine safety and possible clinical benefits. The clinical investigation is a first-in-human trial to use the NK4 gene and to block the HGF/c-Met pathway with gene medicine. We conducted in vivo animal experiments to examine the safety level as one of the preclinical studies, and showed that Ad DNA administered in the pleural cavity was detected in many parenchymal organs. Biochemical and pathological analyses showed that liver damages were the major adverse effects with little toxicity to other organs. These studies firstly demonstrated biodistribution and transgene expression after an intrapleural injection of Ad vectors in an animal study, which contrasts with an intravenous injection showing relatively rapid clearance of Ad-NK4. DISCUSSION: The clinical study can also provide information regarding production of NK4 protein and antibody against NK4, and inhibition levels of the HGF/c-Met pathway by detecting dephosphorylation of c-Met in mesothelioma cells. These data will be crucial to judge whether local production of NK4 molecules can be an anti-cancer strategy. TRIAL REGISTRATION: UMIN clinical trials registry, Japan. Register ID: UMIN15771.

A combined lymphokine-activated killer (LAK) cell immunotherapy and adenovirus-p53 gene therapy for head and neck squamous cell carcinoma.

BACKGROUND: The antitumor activity of lymphokine activated killer (LAK) cells immunotherapy is not always effective in all patients, especially when used alone. In this study, we investigated the in vitro antitumor activities of a combination of LAK immunotherapy and gene therapy employing an adenovirus carrying the p53 gene (Ad-p53) in human head and neck squamous cell carcinoma. MATERIALS AND METHODS: The in vitro cytotoxicity of LAK cells was tested in H891 cells infected with or without Ad-p53, and the mRNA expression levels of natural killer group 2D ligands (UL16 binding protein (ULBP) 1 to 5) and tumor necrosis factor (TNF-α) in these cells were measured by real-time reverse transcription polymerase chain reaction. RESULTS: Ad-p53 infection increased the cytotoxicity of LAK cells against H891 cells, and also increased the mRNA expression levels of the ULBPs in H891 cells and TNF-α in the LAK cells. CONCLUSION: The antitumor activities of LAK cells in H891 cells were enhanced by Ad-p53. CONCLUSION: The combinational therapy of LAK immunotherapy and Ad-p53 gene therapy may represent a new paradigm for the treatment of head and neck cancer.

Oral administration of genetically modified Bifidobacterium displaying HCV-NS3 multi-epitope fusion protein could induce an HCV-NS3-specific systemic immune response in mice.

More than 170 million people worldwide are chronic HCV (Hepatitis C virus) carriers, and about 30% of them will develop progressive liver disease, such as cirrhosis and hepatocellular carcinoma. A combination of pegylated interferon-α with ribavirin, the standard treatment for HCV infection, has been effective in fewer than 50% of patients infected with HCV genotype 1. A strong T cell response against the nonstructural protein 3 (NS3) is important for recovery from acute HCV infection, and an early multi-specific CD4+ helper and CD8+ cytotoxic T cell response is critical for HCV clearance. In the present study, we successfully constructed a genetically modified Bifidobacterium longum (B. longum) displaying recombinant HCV-NS3 peptides containing some CD4 and CD8 epitopes located in the HCV-NS3 region as an oral vaccine against chronic HCV infection. The oral administration of this vaccine could induce NS3-specific immune responses in mice through intestinal mucosal immunity. Our findings suggest that this novel oral vaccine has great potential as a novel oral vaccine against chronic HCV infection.

Gene silencing with siRNA targeting E6/E7 as a therapeutic intervention against head and neck cancer-containing HPV16 cell lines.

CONCLUSION: Our results indicate that siRNA E6 and/or E7 may have potential as a gene-specific therapy for human papillomavirus (HPV) type 16 (HPV16)-related squamous cell carcinoma of the head and neck (HNSCC). OBJECTIVES: To evaluate the effectiveness of siRNA targeting E6 and/or E7 on the in vitro and in vivo growth suppression of HPV16-related HNSCC. METHODS: HPV16-related HNSCC (UM-SCC47) cell lines were used for the present study. Expression of HPV viral oncogenes E6 and/or E7 and their cellular targets, p53 and pRb, was evaluated by real-time PCR, Western blotting, and immunofluorescence staining. To study the effect of siRNA on tumor growth in vivo, we developed animal models. Representative tumors harvested from each group were processed for apoptosis analyses (TUNEL assay) and immunofluorescence staining for p53 and pRb. RESULTS: E6 and E7 oncogenes of HPV16 were down-regulated by E6 and/or E7 targeting siRNAs, respectively. The expression of p53 and pRb proteins in both the E6 siRNA group and E7 siRNA group was up-regulated compared with those of control groups. The cellular proliferation and apoptosis indexes of E6 and/or E7 siRNA groups were higher than those of controls. In vivo studies showed significant inhibitory effect of E6 and/or E7 siRNA compared with those of control groups, which was consistent with in vitro studies.

Intravenous injection of irradiated tumor cell vaccine carrying oncolytic adenovirus suppressed the growth of multiple lung tumors in a mouse squamous cell carcinoma model.

BACKGROUND: Although cancer therapy using replication-selective oncolytic adenoviruses has been available for many years, its anti-tumor efficacy is suboptimal as a result of low and nonspecific infectivity that depends on coxsackie adenovirus receptor expression of the target cancer and normal cells, and generation of an anti-adenovirus neutralizing antibody. In addition, concerns of triggering a severe innate immune response against the adenovirus limit the systemic administration. We developed the carrier cell-based oncolytic virus system (CBOVS) using irradiated tumor cells as carrier cells and concealing the adenovirus (Ad-IAI.3B) inside to improve the specific infectivity. We investigated the anti-tumor effect of CBOVS in a multiple lung tumor mouse model. METHODS: The ability of CBOVS to infect Ad-IAI.3B to the target cancer cells was examined in vitro in the presence of anti-adenovirus antibodies. To evaluate the systemic effect of CBOVS, we intravenously injected CBOVS into mice with lung tumors (KLN205 cell lines). RESULTS: CBOVS enhanced the infectivity of Ad-IAI.3B to tumor cells in the presence of anti-adenovirus antibodies in vitro. Intravenous injections of CBOVS produced an accumulation of the adenovirus in the lung-bearing tumors and produced a strong anti-tumor effect in vivo. Furthermore, lymphocytes collected from the CBOVS-treated mice induced an increase in cytokines related to the Th1 response (interferon-γ, interleukin-12) by pulsing with KLN205. CONCLUSIONS: These findings suggest that CBOVS could protect adenoviruses from neutralizing antibodies and systemically deliver them to lung tumors. Furthermore, CBOVS appears to have potential as a tumor cell vaccine that activates cytotoxic immunity against cancer cells.

Immobilization of 293 cells using porous support particles for adenovirus vector production.

Adenovirus vector production by anchorage-independent 293 cells immobilized using porous biomass support particles (BSPs) was investigated in static and shake-flask cultures for efficient large-scale production of adenovirus vectors for gene therapy applications. The density of cells immobilized within BSPs was evaluated by measuring their WST-8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt) reduction activity. In shake-flask culture, 293-F cells, which were adapted to serum-free suspension culture, were not successfully retained within reticulated polyvinyl formal (PVF) resin BSPs (2 × 2 × 2 mm cubes) with matrices of relatively small pores (pore diameter 60 µm). When the BSPs were coated with a cationic polymer polyethyleneimine, a high cell density of more than 10(7) cells cm(-3)-BSP was achieved in both static and shake-flask cultures with regular replacement of the culture medium. After infection with an adenovirus vector carrying the enhanced green fluorescent protein gene (Ad EGFP), the specific Ad EGFP productivity of the immobilized cells was comparable to the maximal productivity of non-immobilized 293-F cells by maintaining favorable conditions in the culture environment.

Adenovirus vector production using low-multiplicity infection of 293 cells.

The use of low-multiplicity infection of 293 cells in static culture with regular medium replacement was investigated for efficient large-scale production of adenovirus vectors for gene therapy applications. An adenovirus vector carrying the enhanced green fluorescent protein gene (Ad EGFP) was used to infect 293-F cells at a low multiplicity of infection (MOI) of 0.00001-0.1 transductional unit (TU) cell(-1). The cells, which have the ability to grow in suspension, were incubated in T-flasks and the serum-free culture medium was replaced with fresh medium via centrifugation every 2 days. Because only a small proportion of cells were initially infected at low MOIs (<1 TU cell(-1)), uninfected cells continued to grow until they were infected by progeny adenoviruses released from previously infected cells. When 293-F cells at a relatively low density of 1 x 10(5) cells cm(-3) were infected with Ad EGFP at a low MOI of 0.001 TU cell(-1), the vector yield was 2.7-fold higher than the maximum yield obtained with high-multiplicity infection (MOI = 10 TU cell(-1)) in batch culture. These results indicate that efficient adenovirus vector production using low MOIs is achieved by minimization of either nutrient depletion and/or accumulation of inhibitory metabolites in the culture medium.