Targeted gene therapy toward astrocytoma using a Cre/loxP-based adenovirus system

Brain Res. 2006 Apr 7;1081(1):34-43. doi: 10.1016/j.brainres.2006.01.105. Epub 2006 Mar 10.


The aim of this study was to establish a novel adenovirus-based gene therapy system targeting astrocytoma. For this purpose, the Cre recombinase (Cre)/loxP system together with the astrocytoma-specific promoter for GFAP were used. We constructed an adenovirus (Ad) vector that expressed Cre under the control of the GFAP promoter (AxGFAPNCre), as well as another Ad vector containing a switching unit. The latter vector contained a stuffer sequence encoding GFP (AxCALGLTK) with a functional polyadenylation signal between two loxP sites, followed by the herpes simplex virus thymidine kinase (HSV-TK) gene under the control of the CAG promoter. In this system, gene expression of either the stuffer sequence (GFP) or the downstream gene (HSV-TK) was switched on by co-expression of Cre recombinase. Western blot analysis demonstrated specific expression of high levels of TK protein in C6 glioma cells after co-infection of AxGFAPNCre and AxCALGLTK. In vivo, AxGFAPNCre/AxCALGLTK injection into C6 gliomas in the subcutaneous tissue of nude mice followed by intraperitoneal ganciclovir (GCV) treatment significantly suppressed tumor growth compared with control mice. Co-infection of AxGFAPNCre and AxCALNLLacZ resulted in LacZ expression in C6 glioma cells and some reactive astrocytes, whereas GFP was expressed in other cell types surrounding the injected site. Furthermore, a combination of AxGFAPNCre/AxCALGLTK and intraperitoneal GCV injection significantly regressed intracranial C6 gliomas in the rat striatum and prolonged the survival time compared with control rats. The present results indicate that this cell-type-specific gene therapy using a Cre/loxP adenovirus system is both operational and effective, at least against astrocytoma.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Astrocytoma / pathology
  • Astrocytoma / therapy*
  • Blotting, Western / methods
  • Brain Neoplasms / pathology
  • Brain Neoplasms / therapy
  • Brain Neoplasms / virology
  • Dose-Response Relationship, Drug
  • Extracellular Matrix Proteins / biosynthesis
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / therapeutic use*
  • Gene Transfer Techniques
  • Genetic Therapy* / methods
  • Humans
  • Immunohistochemistry / methods
  • Integrases / biosynthesis
  • Integrases / genetics
  • Integrases / therapeutic use*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Transplantation / methods
  • Protein-Lysine 6-Oxidase / biosynthesis
  • Protein-Lysine 6-Oxidase / genetics
  • Protein-Lysine 6-Oxidase / therapeutic use*
  • Rats
  • Rats, Wistar
  • Time Factors
  • Tumor Cells, Cultured
  • Viral Proteins / biosynthesis
  • Viral Proteins / genetics
  • Viral Proteins / therapeutic use*


  • Extracellular Matrix Proteins
  • Viral Proteins
  • Lox protein, mouse
  • Protein-Lysine 6-Oxidase
  • Cre recombinase
  • Integrases