Introduction of foreign nucleic acids into cells via electroporation with the intention of treating cancer diseases is becoming more and morerecognised as an effective treatment method in veterinary and human medicine. The efficiency of gene electrotransfer depends on the physical properties of the electrical field, the type of inserted nucleic acid and the biological tissue factors. The gene electrotransfer activates numerous cytosolic sensors for nucleic acids, which leads to the activation of a immune response with the help of inflammatory cytokines.
We investigated whether the gene electrotransfer of nucleic acids is cytotoxic and whether it causes the activation of cytosolic sensors in the human Sk-Mel28 melanoma cells and the HT29 colorectal adenocarcinoma cells. We also observed the morphological changes of cells following gene electrotransfer. We conclude that gene electrotransfer to Sk-Mel28 cells, using EP2 protocol, has no cytotoxic effect, whereas in HT29 cells the cytotoxicity depends on the physical properties of the pulses. During observation of morphological changes, we noticed that after gene electrotransfer a certain percentage of cells became apoptotic or necrotic, and the type of cell death depended on the physical properties of the pulses. In the Sk-Mel28 cell line, we did not observe increased expression of cytosolic sensorsm after GET, whereas in HT29 after GET of selected nucleic acids, primarily the Vax plasmid, we observe increased expression of cytosolic sensors DDX60, RIG-I and IFI16 independently of the properties of the electroporation pulses. Increased expression of the inflammatory cytokine tumour necrosis factor α was also observed.
|
