FIG. 5.

DNA damage signaling and fate of NIH3T3 cells after nucleofection with plasmid DNAs. Cells were nucleofected by Amaxa with phGfΔG, ph2pΔG, or ph3pΔG plasmids. At the indicated times post-transfection, cells or supernatants were collected. (A) Proteins of cell lysates were immunobloted for detection of γ-histone 2A.X. Detection of β-actin was performed as a control for sample loading. (B) The medium of the growing cells was collected to evaluate cytotoxicity by measuring LDH. Values are related to that of LDH release obtained by treatment with 9% Triton X-100 (=100%). Data represent the mean values obtained by measuring duplicates of three independent experiments. (C) Cell proliferation was followed by measuring bioreduction of tetrazolium salt, using an ELISA reader (450 nm). OD values were aligned to the baseline (0 time, OD value) and the resulting fold increase values were plotted. Three independent experiments were performed, and comparable results were obtained. For better graph clarity, the results of one representative experiment are presented. For all experiments (A–C), mock-transfected cells were used as a negative control.