Efficient Therapeutic Protein Expression Using Retroviral Replicating Vector with 2A Peptide in Cancer Models.
Hum Gene Ther
; 29(4): 437-451, 2018 04.
Article
en En
| MEDLINE
| ID: mdl-29216761
ABSTRACT
Toca 511, a retroviral replicating vector (RRV), uses an internal ribosomal entry site (IRES) to express an optimized yeast cytosine deaminase (yCD2), which converts 5-fluorocytosine to 5-fluorouracil. This configuration is genetically stable in both preclinical mouse models and human clinical trials. However, the use of IRES (â¼600 bp) restricts choices of therapeutic transgenes due to limits in RRV genome size. This study replaced IRES with 2A peptides derived from picornaviruses with or without a GSG linker. The data show that GSG-linked 2A (g2A) peptide resulted in higher polyprotein separation efficiency than non-GSG linked 2A peptide. The study also shows that RRV can tolerate insertion of two separate 2A peptides to allow expression of two transgenes without compromising the assembly and function of the virus in addition to insertion of a single 2A peptide to confirm genetic stability with yCD2, green fluorescent protein, and HSV-1 thymidine kinase. In a parallel comparison of the RRV-IRES-yCD2 and RRV-g2A-yCD2 configurations, the study shows the yCD2 protein expressed from RRV-g2A-yCD2 has higher activity, resulting in a higher survival benefit in an intracranial tumor mouse model. These data enable a wider range of potential product candidates that could be developed using the RRV platform.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Neoplasias Encefálicas
/
Terapia Genética
/
Sitios Internos de Entrada al Ribosoma
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Vectores Genéticos
Límite:
Animals
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Humans
Idioma:
En
Revista:
Hum Gene Ther
Asunto de la revista:
GENETICA MEDICA
/
TERAPEUTICA
Año:
2018
Tipo del documento:
Article