Overexpression of Chk2 by transfection of wild-type Chk2 or Chk2 dead allele in A2780 cells. A2780 cells were transfected with wild-type HA-Chk2 (a) or HA-Chk2 D347A (b) for overexpression of Chk2. Blank vectors were transfected as controls. Twenty-four hours after transfection, cells were treated with cisplatin (3 μM) for 1 hr and then were incubated with fresh media. Cell lysate was obtained and performed for Western blot analysis with antibodies of anti-p-p53(Ser15), anti-p-p53(Ser20), anti-p53, anti-p-Chk2(Thr68), anti-Chk2, anti-p21, or anti-β-Actin, respectively.