RESUMO
Although oncolytic adenoviruses are promising cancer therapy agents, for effective oncolytic activity, viruses need to specifically infect and effectively replicate in cancer cells but not in normal cells. We have previously identified a pancreatic cancer-targeting ligand, SYENFSA (SYE), by screening an adenovirus library displaying random peptides against human pancreatic cancer cells and reported that a survivin promoter-regulated adenovirus, displaying the SYE ligand (AdSur-SYE), provided effective oncolysis of pancreatic ductal adenocarcinoma (PDAC) in a preclinical study. As we examined the infectivity of AdSur-SYE in human surgical specimens of various pancreatic tumors, we unexpectedly found that AdSur-SYE showed high gene transduction efficiency for pancreatic neuroendocrine tumors (PNETs) as well as for PDAC, 9.1- and 6.2-fold, respectively, compared to that of the nontargeting virus (AdSur). The infectivity of both vectors was almost the same in other cancers and organs such as the pancreas. Immunostaining indicated that the cells infected with AdSur-SYE were PNET cells but not stromal cells. AdSur-SYE showed a significantly higher oncolytic potency than that of AdSur in human PNET cell lines, and intratumoral infection with AdSur-SYE completely diminished subcutaneous tumors in a murine model, in which AdSur-SYE effectively proliferated and spread. AdSur-SYE exerted a stronger oncolytic effect in primary PNET cells cocultured with mouse embryonic fibroblasts than AdSur did. Thus, AdSur-SYE shows promise as a next-generation therapy for PNET.
Assuntos
Adenoviridae/genética , Vetores Genéticos/genética , Ligantes , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/patologia , Terapia Viral Oncolítica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Peptídeos/genética , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Genes Reporter , Terapia Genética , Vetores Genéticos/administração & dosagem , Humanos , Imuno-Histoquímica , Proteínas Inibidoras de Apoptose/genética , Camundongos , Tumores Neuroendócrinos/terapia , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/genética , Neoplasias Pancreáticas/terapia , Regiões Promotoras Genéticas , Survivina , Transdução Genética , Transgenes , Carga Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Optimizing targeting strategies for vectors in order to enhance antitumor activity and secure patient safety is important for cancer gene therapy. We previously identified two pancreatic cancer-targeting ligands (PFWSGAV: PFW and SYENFSA: SYE) by screening an adenovirus library in vivo and in vitro, respectively. MATERIALS AND METHODS: To examine clinical usefulness, we assessed gene-transduction efficiency using surgically-resected pancreatic cancer specimens and ascites cells. RESULTS: For surgical specimens, vectors displaying PFW and SYE improved transduction efficiency by 4.4- and 4.3-fold, respectively. The SYE-displaying vector was >2-fold more efficient for all seven cases, whereas the PFW-displaying vector increased efficiency in two out of four cases. For ascites samples, both vectors increased gene-transduction efficiency of epithelial cell adhesion molecule (EpCAM)-positive ascites cells by >2-fold in two out of five cases. CONCLUSION: Both vectors enhanced adenovirus infectivity of pancreatic cancer cells and have potential for gene therapy of pancreatic cancer; therefore they should be further evaluated in clinical studies.
Assuntos
Adenoviridae/genética , Ascite/genética , Ascite/virologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/virologia , Linhagem Celular Tumoral , Molécula de Adesão da Célula Epitelial/genética , Terapia Genética/métodos , Humanos , Pâncreas/virologia , Transdução Genética/métodos , Neoplasias PancreáticasRESUMO
The addition of a targeting strategy is necessary to enhance oncolysis and secure safety of a conditionally replicative adenovirus (CRAd). We have constructed an adenovirus library displaying random peptides on the fiber, and have successfully identified a pancreatic cancer-targeting ligand (SYENFSA). Here, the usefulness of cancer-targeted CRAd for pancreatic cancer was examined as a preclinical study. First, we constructed a survivin promoter-regulated CRAd expressing enhanced green fluorescent protein gene (EGFP), which displayed the identified targeting ligand (AdSur-SYE). The AdSur-SYE resulted in higher gene transduction efficiency and oncolytic potency than the untargeted CRAd (AdSur) in several pancreatic cancer cell lines. An intratumoral injection of AdSur-SYE significantly suppressed the growth of subcutaneous tumors, in which AdSur-SYE effectively proliferated and spread. An ectopic infection in adjacent tissues and organs of intratumorally injected AdSur-SYE was decreased compared with AdSur. Then, to examine whether the targeting ligand actually enhanced the infectivity of CRAd in human pancreatic cancer tissues, tumor cells prepared from surgical specimens were infected with viruses. The AdSur-SYE increased gene transduction efficiency 6.4-fold higher than did AdSur in single cells derived from human pancreatic cancer, whereas the infectivity of both vectors was almost the same in the pancreas and other cancers. Immunostaining showed that most EGFP(+) cells were cytokeratin-positive in the sliced tissues, indicating that pancreatic cancer cells but not stromal cells were injected with AdSur-SYE. AdSur-SYE resulted in a stronger oncolysis in the primary pancreatic cancer cells co-cultured with mouse embryonic fibroblasts than AdSur did. CRAd in combination with a tumor-targeting ligand is promising as a next-generation of oncolytic virotherapy for pancreatic cancer.
