Pre-clinical investigation of the synergy effect of interleukin-12 gene-electro-transfer during partially irreversible electropermeabilization against melanoma

Abstract

Background Melanoma is a very aggressive skin tumor that can be cured when diagnosed and treated in its early stages. However, at the time of identification, the tumor is frequently in a metastatic stage. Intensive research is currently ongoing to improve the efficacy of the immune system in eliminating cancer cells. One approach is to boost the activation of cytotoxic T cells by IL-12 cytokine that plays a central role in the activation of the immune system. In parallel, physical methods such as electropermeabilization-based treatments are currently under investigation and show promising results. Methods In this study, we set electrical parameters to induce a partial-irreversible electropermeabilization (pIRE) of melanoma to induce a sufficient cell death and potential release of tumor antigens able to activate immune cells. This protocol mimics the situation where irreversible electropermeabilization is not fully completed. Then, a peritumoral plasmid IL-12 electrotransfer was combined with pIRE treatment. Evaluation of the tumor growth and survival was performed in mouse strains having a different immunological background (C57Bl/6 (WT), nude and C57Bl6 (TLR9−/−)). Results pIRE treatment induced apoptotic cell death and a temporary tumor growth delay in all mouse strains. In C57Bl/6 mice, we showed that peritumoral plasmid IL-12 electrotransfer combined with tumor pIRE treatment induced tumor regression correlating with a local secretion of IL-12 and IFN-γ. This combined treatment induced a growth delay of distant tumors and prevented the emergence of a second tumor in 50% of immunocompetent mice. Conclusions The combination of pIL-12 GET and pIRE not only enhanced survival but could bring a curative effect in wild type mice. This two-step treatment, named Immune-Gene Electro-Therapy (IGET), led to a systemic activation of the adaptive immune system and the development of an anti-tumor immune memory. Electronic supplementary material The online version of this article (10.1186/s40425-019-0638-5) contains supplementary material, which is available to authorized users.

Localized Interleukin-12 for Cancer Immunotherapy

“…Two of 4 cured mice completely resisted tumor rechallenge while the remaining two experienced delayed tumor growth from the rechallenge. This pIL-12 plus pIRE approach was found to delay, but not eliminate distant, untreated tumors in about half of the mice (139).…”

“…By further enhancing electric field intensity and/or pulse length, it is possible to directly kill tumor cells and release tumor antigens via irreversible electroporation. In one recent study, partial-irreversible electropermeabilization (pIRE) administered after peritumoral electrotransfection with pIL-12 caused complete regression of about 40-50% of treated B16F10 tumors (139). Two of 4 cured mice completely resisted tumor rechallenge while the remaining two experienced delayed tumor growth from the rechallenge.…”

Enhance transgene responses through improving cellular uptake and intracellular trafficking by bio-inspired non-viral vectors

“…However, the poor intracellular bioavailability and rapid degradation of the gene in the blood circulation, endosome or lysosome hinder their clinical application. It is well known that the lack of safe and efficient non-viral delivery vectors seriously influences the therapeutic efficacy in the clinic [10,11].…”

Analysis of DNA mobility and gene electrotransfer in 3D in vitro collagen gel model

“…Electroporation is already successfully applied in different biomedical applications, including: electrofusion [13,14]; electrochemotherapy [15,16]; irreversible tissue ablation [17]; DNA vaccination [18,19] and gene electrotransfer [20][21][22]. Today gene electrotransfer is widely used to introduce DNA into different cells [23,24] and tissues [1,25,26] due to its efficiency, safety and easy application. It is also relevant in a variety of clinical settings including cancer therapy, modulation of pathogenic immune responses, delivery of therapeutic proteins and drugs [27,28].…”