RESUMO
Oncolytic virotherapy using adenoviruses has potential therapeutic benefits for a variety of cancers. We recently developed MOA5, a tumor-specific midkine promoter-regulated oncolytic vector based on human adenovirus serotype 5 (Ad5). We modified the binding tropism of MOA5 by replacing the cell-binding domain of the Ad5 fiber knob with that from another adenovirus serotype 35 (Ad35); the resulting vector was designated MOA35. Here we evaluated the therapeutic efficacies of MOA5 and MOA35 for human osteosarcoma. Midkine mRNA expression and its promoter activity was significantly high in five human osteosarcoma cell lines, but was restricted in normal cells. Very low levels of adenovirus cellular receptor coxsackievirus/adenovirus receptor (CAR) (Ad5 receptor) expression were observed in MNNG-HOS and MG-63 cells, whereas high levels of CAR expression were seen in the other osteosarcoma cell lines. By contrast, CD46 (Ad35 receptor) was highly expressed in all osteosarcoma cell lines. Infectivity and in vitro cytocidal effect of MOA35 was significantly enhanced in MNNG-HOS and MG-63 cells compared with MOA5, although the cytocidal effects of MOA5 were sometimes higher in high CAR-expressing cell lines. In MG-63 xenograft models, MOA35 significantly enhanced antitumor effects compared with MOA5. Our findings indicate that MOA5 and MOA35 allow tailored virotherapy and facilitate more effective treatments for osteosarcoma.
Assuntos
Fatores de Crescimento Neural/genética , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/fisiologia , Osteossarcoma/terapia , Osteossarcoma/virologia , Infecções por Adenoviridae/genética , Adenovírus Humanos/genética , Adenovírus Humanos/fisiologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus/genética , Feminino , Vetores Genéticos/genética , Células HEK293 , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Midkina , Vírus Oncolíticos/genética , Osteoblastos/virologia , Osteossarcoma/genética , Regiões Promotoras Genéticas , Receptores Virais/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Retroviral replicating vectors (RRVs) have been shown to achieve efficient tumor transduction and enhanced therapeutic benefit in a wide variety of cancer models. Here we evaluated two different RRVs derived from amphotropic murine leukemia virus (AMLV) and gibbon ape leukemia virus (GALV), in human malignant mesothelioma cells. In vitro, both RRVs expressing the green fluorescent protein gene efficiently replicated in most mesothelioma cell lines tested, but not in normal mesothelial cells. Notably, in ACC-MESO-1 mesothelioma cells that were not permissive for AMLV-RRV, the GALV-RRV could spread efficiently in culture and in mice with subcutaneous xenografts by in vivo fluorescence imaging. Next, GALV-RRV expressing the cytosine deaminase prodrug activator gene showed efficient killing of ACC-MESO-1 cells in a prodrug 5-fluorocytosine dose-dependent manner, compared with AMLV-RRV. GALV-RRV-mediated prodrug activator gene therapy achieved significant inhibition of subcutaneous ACC-MESO-1 tumor growth in nude mice. Quantitative reverse transcription PCR demonstrated that ACC-MESO-1 cells express higher PiT-1 (GALV receptor) and lower PiT-2 (AMLV receptor) compared with normal mesothelial cells and other mesothelioma cells, presumably accounting for the distinctive finding that GALV-RRV replicates much more robustly than AMLV-RRV in these cells. These data indicate the potential utility of GALV-RRV-mediated prodrug activator gene therapy in the treatment of mesothelioma.
Assuntos
Vetores Genéticos/genética , Vírus da Leucemia do Macaco Gibão/genética , Neoplasias Pulmonares/genética , Mesotelioma/genética , Transdução Genética , Animais , Linhagem Celular Tumoral , Citosina Desaminase/genética , Citosina Desaminase/metabolismo , Modelos Animais de Doenças , Feminino , Expressão Gênica , Ordem dos Genes , Terapia Genética , Vetores Genéticos/administração & dosagem , Humanos , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Mesotelioma Maligno , Camundongos , Pró-Fármacos , Replicação Viral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Replication-competent retrovirus (RCR) vectors have been shown to achieve significantly enhanced tumor transduction efficiency and therapeutic efficacy in various cancer models. In the present study, we investigated RCR vector-mediated prodrug activator gene therapy for the treatment of malignant mesothelioma, a highly aggressive tumor with poor prognosis. RCR-GFP vector expressing the green fluorescent protein marker gene successfully infected and efficiently replicated in human malignant mesothelioma cell lines, as compared with non-malignant mesothelial cells in vitro. In mice with pre-established subcutaneous tumor xenografts, RCR-GFP vector showed robust spread throughout entire tumor masses after intratumoral administration. Next, RCR-cytosine deaminase (RCR-CD), expressing the yeast CD prodrug activator gene, showed efficient transmission of the prodrug activator gene associated with replicative spread of the virus, resulting in efficient killing of malignant mesothelioma cells in a prodrug 5-fluorocytosine (5FC)-dose dependent manner in vitro. After a single intratumoral injection of RCR-CD followed by intraperitoneal administration of 5FC, RCR vector-mediated prodrug activator gene therapy achieved significant inhibition of subcutaneous tumor growth, and significantly prolonged survival in the disseminated peritoneal model of malignant mesothelioma. These data indicate the potential utility of RCR vector-mediated prodrug activator gene therapy in the treatment of malignant mesothelioma.