Extracellular DNA Containing (dG)n Motifs Penetrates into MCF7 Breast Cancer Cells, Induces the Adaptive Response, and Can Be Expressed

Figure 8

The possible participation of dGn motifs in the implementation of the biological activity of cell-free GC-DNA. A summary of events developing in MCF7 cells exposed to pEGFP-Gn. pEGFP-Gn approaches the cell surface, and dG within dGn is easily oxidized. pEGFP-oxo(Gn) binds to the cell, stimulating NOX4 expression, synthesis of ROS, and further oxidation of the bases. (I) Cell DNA is damaged by the ROS. The DNA damage response is induced. (II) Oxidized pEGFP-oxo(Gn) is transfected into the nucleus of the cell. Transfection mechanism is still unknown. Perhaps, the yet unknown oxy-DNA sensors are involved in the transfection. EGFP gene in pEGFP-oxo(Gn) molecules with intact promoter is expressed.