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Pretreatment with protease is a useful experimental strategy for enhancing adenovirus-mediated cancer gene therapy
N Kuriyama1, H Kuriyama, C M Julin
1Preuss Laboratory for Molecular Neuro-oncology, Brain Tumor Research Center, Departments of Neurological Surgery and Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA.
Abstract:
A key impediment to the development of effective virus-mediated gene therapy for cancer is the low level of gene transfer that occurs after the administration of recombinant viral vectors. Improving in vivo infection and transduction efficiency is an important goal for gene therapy. The limited distribution of gene delivery is particularly problematic when large vectors such as recombinant adenoviruses and retroviruses are used to mediate transgene delivery to solid tumors. To facilitate the spread of virus, we have investigated the potential of administering proteases prior to the intratumoral inoculation of recombinant replication deficient adenovirus. For these studies, we chose proteases that are active against collagen and the other extracellular matrix proteins found in primary brain tumor tissue, but are not widely expressed in normal brain. Various concentrations of a mixture of collagenase/dispase or trypsin were inoculated into xenografts of human glioblastoma multiforme-derived brain tumor cell lines U87, U251, and SF767. Subsequently, recombinant adenovirus encoding the beta-galactosidase gene was administered and tumor tissue was examined for evidence of virus infection. Both collagenase/dispase and trypsin enhanced virus infection, indicating that protease pretreatment may be a useful strategy for enhancing virus-mediated gene transduction for many in vivo applications.
Insights
Protease pretreatment enhances virus delivery for cancer gene therapy. This strategy improves in vivo infection and transduction efficiency, overcoming a key challenge in developing effective viral vector therapies.
Area of Science:
- Oncology
- Gene Therapy
- Virology
Background:
- Low gene transfer efficiency of viral vectors limits cancer gene therapy effectiveness.
- Efficient in vivo infection and transduction are crucial for successful gene therapy.
- Limited distribution of gene delivery vectors, especially large ones like adenoviruses, hinders solid tumor treatment.
Purpose of the Study:
- To investigate the potential of protease administration to enhance virus spread and gene transfer.
- To improve in vivo infection and transduction efficiency of recombinant adenoviruses in solid tumors.
Main Methods:
- Proteases (collagenase/dispase or trypsin) were administered intratumorally prior to adenovirus inoculation in human glioblastoma xenografts (U87, U251, SF767).
- Recombinant adenovirus encoding the beta-galactosidase gene was used for gene delivery.
- Tumor tissues were analyzed for evidence of virus infection post-treatment.
Main Results:
- Both collagenase/dispase and trypsin significantly enhanced virus infection in tumor xenografts.
- Protease pretreatment facilitated improved gene transduction efficiency.
- The proteases used were active against extracellular matrix proteins in brain tumors but not widely expressed in normal brain.
Conclusions:
- Protease pretreatment is a promising strategy to enhance virus-mediated gene transduction for in vivo applications.
- This approach can overcome limitations in gene delivery efficiency for solid tumors.
- Further development of protease-enhanced gene therapy holds potential for improved cancer treatment outcomes.