Fig. 6

Depletion of Bcl2 by RNAi enhances mtAPE1 activity and promotes mtDNA repair in association with deceased frequency of mtDNA mutations. a. Bcl2 shRNA or control shRNA was transfected into H460 cells. Bcl2 expression was analyzed by Western blot. APE1 endonuclease activity was compared in H460 cells expressing Bcl2 shRNA or control shRNA. b and c. H460 cells expressing Bcl2 shRNA or control shRNA were treated with 100 μM H₂O₂ (b) and 200 μM NNK (c) for 60 min. Cells were then washed three times and incubated in fresh culture medium for indicated times. mtDNA damage or mtDNA mutation was analyzed as described in “Methods”. Quantification data are mean ± SD from three independent experiments