Methylated EDSBs may be repaired by an ATM-dependent pathway. (A) Immunoblots of ATM and DNA-PKcs in ATM shRNA-transfected HeLa cells. GAPDH is included as a loading control. (B) methylation of L1 and methylation of L1-EDSB analysis of ATM shRNA-transfected HeLa cells. (C) methylation of L1 and methylation of L1-EDSB analysis of ATM shRNA- and control shRNA-transfected HeLa cells. The level of EDSB methylation of ATM shRNA-transfected cells was higher than EDSBs of all tests in this and a previous study (1). Each circle represents an individual methylation of L1 or L1-EDSB result. (D) Levels of L1-EDSBs. The data represent the number of L1-EDSB genomes per genome digested with Eco RV and Alu I and ligated to the linkers or the number of L1-EDSB genomes per control genome. (B) and (D) Data represent means ± SEM, with statistical significance determined by two-tailed paired t-test.