Introduction. Silver nanoparticles (AgNPs) are widely applied in various fields: medicine, pharmaceutics, agriculture and others. They are suggested to exhibit antibacterial, antifungal, antiviral and anticancer activities. However, their effects depend on particle size, shape, physicochemical properties, synthesis method and target biological system. Lewis Lung Carcinoma (LLC) cells are an aggressive tumor model characterized by high oncogenicity and relative resistance to a range of anticancer drugs. The purpose of this study was to assess the influence of AgNPs on LLC cells in terms of cytotoxicity, apoptotic gene expression and potential genotoxicity.
Methods. LLC cells were obtained from the Cell Bank of the R.E.Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of the NAS of Ukraine and were cultured according to standard methods. Colloidal silver concentrate coated with natural resin was manufactured by Noble Elements LLC (USA). Nominal particle size was 10±2 nm and a silver concentration of 20000 ppm was used. Cytotoxicity of AgNPs was determined using the MTT assay. The studied concentration of NPs was 10-1000 ppm. Evaluation of apoptosis-associated gene expression was carried out with RT-qPCR analysis and amplification with primers to short nucleotide repeats was performed to determine the genotoxicity effect.
Results. The results indicated that the IC₅₀ value of AgNPs was 750 ppm; concentrations of 320 and 640 ppm were selected for the subsequent research. Analysis of apoptosis-related gene transcriptional activity showed slight changes in p53 and caspase 3 and 8 expression in treated LLC cells. The comparative analysis of PCR product patterns revealed differences between control and treated samples. The most prominent differences, characterized by the absence of some amplicons in the banding profile, were observed in LLC cells treated at 640 ppm.
Conclusions. The data suggest that the inhibitory effect of investigated AgNPs on LLC cell viability is more likely to involve oxidative stress response mechanisms rather than the apoptotic pathway.
