Related Experiment Videos
Vector delivery methods and targeting strategies for gene therapy of brain tumors
1Dept. Neurological Science, University of Liverpool, Clinical Sciences Centre, Lower Lane, Liverpool L9 7LJ, United Kingdom. rainov@liv.ac.uk
Abstract:
Efficient virus and non-virus vector systems for gene transfer to tumor cells have been developed and tested in cell culture and in animal experiments. With some of the earliest and most comprehensively evaluated vectors, such as retroviruses, advanced clinical trials were performed in tumor patients. Malignant primary brain tumors (gliomas) have been chosen for the first clinical studies on novel gene therapy approaches because these tumors are non-metastatic and develop on the largely postmitotic background of normal glial and neuronal tissue. However, the human cancer gene therapy studies performed so far were not as successful as preclinical animal experiments. Furthermore, the clinical studies did not address major limiting factors for in vivo gene therapy, such as insufficient gene transfer rates to the tumor with the used local delivery modalities, and the resulting inability of a particular transgene-prodrug system to confer permanently eradicating cytotoxicity to the whole neoplasm. Critical evaluation of gene transfer and therapy studies has led to the conclusion that, even using identical vectors, the anatomical route of vector administration can dramatically affect both the efficiency of tumor transduction and its spatial distribution, as well as the extent of intratumoral and intracerebral transgene expression. This review concentrates on different physical methods for vector delivery to malignant primary brain tumors in experimental or clinical settings: stereotactic or direct intratumoral injection or convection-enhanced bulk-flow interstitial delivery; intrathecal and intraventricular injection; and intravascular infusion with or without modification of the blood-tumor-barrier. The advantages and drawbacks of the different modes and delivery routes of in vivo vector application, and the possibilities for tumor targeting by modifications of the native tropism of virus vectors or by using tissue-specific or inducible transgene expression are summarized.
Insights
Gene therapy for brain tumors faces challenges with efficient delivery. This review examines physical methods for vector administration to improve gene transfer rates and therapeutic outcomes in malignant gliomas.
Area of Science:
- Oncology
- Gene Therapy
- Neuroscience
Background:
- Gene therapy holds promise for treating malignant primary brain tumors like gliomas.
- Early clinical trials using vectors like retroviruses showed limited success compared to preclinical studies.
- Key limitations include insufficient gene transfer rates and inadequate tumor eradication.
Purpose of the Study:
- To review physical methods for vector delivery to malignant primary brain tumors.
- To evaluate the impact of different delivery routes on gene transfer efficiency and transgene expression.
- To discuss strategies for improving tumor targeting and therapeutic efficacy.
Main Methods:
- Focuses on physical delivery methods for gene therapy vectors.
- Includes stereotactic injection, convection-enhanced delivery, intrathecal/intraventricular injection, and intravascular infusion.
- Considers blood-tumor barrier modifications and vector tropism alterations.
Main Results:
- Vector administration route significantly impacts tumor transduction efficiency and spatial distribution.
- Intracerebral transgene expression levels vary greatly depending on the delivery method.
- Current methods struggle to achieve widespread and sustained tumor cell targeting.
Conclusions:
- Physical delivery methods are crucial for successful in vivo gene therapy in brain tumors.
- Optimizing delivery routes is essential to overcome limitations of current gene therapy approaches.
- Future strategies should focus on enhancing vector targeting and expression for effective glioma treatment.