Duration of the project:

University of Primorska Faculty of Health Sciences
Institute of Oncology Ljubljana

Principal investigator / researcher:

Associate Prof. Maja Čemažar, PhD (SICRIS, ResearchGate)

Link:

Background:

Electroporation is a physical method that uses electric pulses applied to cells or tissues to reorganize structure of the cell membrane. Cell membranes thus become permeable to molecules which otherwise can not cross it. Lately, electroporation is getting consideration also in gene therapy, where it is used as gene delivery method (electrogene therapy). In treatment of cancer, electrogene therapy can be used for electrotransfer of therapeutic genes directly to tumor or into other tissues for systemic release of therapeutic proteins acting on distant tumors. One of promising therapeutic genes that were already tested in electrogene therapy is interleukin-12 (IL-12). IL-12 stimulates innate immunity, by activating natural killer cells to produce interferon-g and adaptive immunity by stimulating differentiation of T lymphocytes Th1 response). In addition, IL-12 has also antiangiogenic properties. Combination of gene therapy with IL-12 for systemic release of IL-12 in combination with radiotherapy is a new field that has not been yet evaluated for treatment of cutaneous and subcutaneous as well as deeper seeded tumors. Therefore, our hypothesis is that electrotransfection of IL-12 into muscle using optimized parameters is efficient electrogene therapy that has therapeutic effect as single therapy and has radiosensitizing effect in combination with radiotherapy.

Methods.
Measurements of in vitro cytotoxicity of recombinant IL-12 and testing of its radiosensitizing effect. In vivo transfection of tumors with electroporation and plasmid DNA encoding IL-12. Intratumoral and peritumoral application of electrogene therapy will be tested in solid subcutaneous tumors and antitumor effectiveness determined. In vivo transfection of muscles with plasmid DNA encoding IL-12 for systemic release of IL-12. Antitumor effectiveness in solid subcutaneous tumors and lung metastases will be determined. Qualitative and quantitative analysis of transfection and expression of IL-12. Determination of antitumor effectiveness of systemic and local combined electrogene immune therapy with IL-12 and radiotherapy.

Relevance and potential impact of the results.
The proposed project is designed as a preclinical project that involves experiments in cell cultures and animal and human tumor models. The results can contribute to the use of electrogene immunotherapy as an adjuvant therapy to radiotherapy. If successful, local potentiation of radiation response can lead to the use of lower irradiation doses and thus lower side effects. Combination of radiotherapy and systemic electrogene immunotherapy can in addition to enhanced local effect, result in systemic effect on micrometastases and has also prophylactic effect.