Figure 1.

DNA-PKcs regulates c-Myc protein expression (Immunoblotting analysis). (A) DNA-PKcs and c-Myc expression in the passage 35 of HeLa-H1 cells transfected with DNA-PKcs specific siRNA construct or HeLa-NC transfected with nonspecific siRNA construct (the same in all figures for HeLa-H1 and HeLa-NC cells). (B) DNA-PKcs and c-Myc expression in HepG2 cells transfected with DNA-PKcs specific siRNA construct (HepG2-H1 and HepG2-H3) or nonspecific siRNA construct (HepG2-NC). (C) Comparison of DNA-PKcs and c-Myc expression between human glioma M059K cells (DNA-PKcs efficient) and M059J cells (DNA-PKcs deficient). (D) Alterations of DNA-PKcs and c-Myc expression in normal human liver L02 cells after exposed to 0, 0.01 and 0.1 pM of TCDD for 4 weeks. (E) Effect of re-depressing TCDD-upregulated DNA-PKcs on c-Myc expression in L02 cells. L02/TCDD-H1 and L02/TCDD-NC cells were generated by exposing L02 cells to 0.1 pM TCDD for two weeks, then transfected with DNA-PKcs specific siRNA or nonspecific siRNA constructs, respectively. Cells grew in normal growth medium without TCDD after primary two weeks of TCDD exposure. (F) c-Myc protein expression in ATM-deficient AT5BIVA cells and human HFC fibroblasts, and the effect by siRNA-mediated suppression of DNA-PKcs.