Cytotoxic effects induced by interferon-ω gene lipofection through ROS generation and mitochondrial membrane potential disruption in feline mammary carcinoma cells

•Three different cell lines were established from a single feline mammary carcinoma tumor.•Each cell line displayed specific differentiation marker patterns and colonies development.•fIFN-ω gene lipofection cytotoxicity varied among the three established cell lines.•fIFN-ω gene lipofection was equally or more efficient than added rfIFN-ω protein.•fIFN-ω action involved ROS generation, mitochondrial potential disruption and Ca2+ uptake. Progress in comparative oncology promises advances in clinical cancer treatments for both companion animals and humans. In this context, feline mammary carcinoma (FMC) cells have been proposed as a suitable model to study human breast cancer. Based on our previous data about the advantages of using type I interferon gene therapy over the respective recombinant DNA derived protein, the present work explored the effects of feline interferon-ω gene (fIFNω) transfer on FMC cells. Three different cell variants derived from a single spontaneous highly aggressive FMC tumor were successfully established and characterized. Lipofection of the fIFNω gene displayed a significant cytotoxic effect on the three cell variants. The extent of the response was proportional to ROS generation, mitochondrial membrane potential disruption and calcium uptake. Moreover, a lower sensitivity to the treatment correlated with a higher malignant phenotype. Our results suggest that fIFNω lipofection could offer an alternative approach in veterinary oncology with equal or superior outcome and with less adverse effects than recombinant fIFNω therapy.