Measuring LINE-1 Activity and the ATP Level in Human Cell Cultures

DNA demethylation makes closed regions of the genome available for transcription and thus causes increased activity of mobile genetic elements (transposons) in the genome. The study of the influence of abnormal activity of transposons on cell energy attracts attention due to the potential possibility of using this effect to create an energy deficit with subsequent launch of cell death programs, which may be relevant for the development of anti-cancer strategies. This paper presents the results of experimental measurements of the ATP level in HEK-293 cells obtained from human embryonic kidneys and the MCF-7 breast cancer cell line under normal and demethylation conditions. The HEK-293 line was transfected with a plasmid containing the LINE-1-EGFP genetic construct, and active insertion of the LINE-1 transposon in the transfected cells was shown. Transposon expression in demethylated MCF-7 cells was shown using real-time PCR. The results of ATP measurements demonstrate an increase in energy stores in cells upon both demethylation and transfection with LINE-1-EGFP. The observed effect suggests that the energy load expected from transposon activation is overwhelmed by the energy release from other cellular processes that occur during demethylation and transfection.