Overexpression of p53 by p53 transfection in A2780 cells. A2780 cells were transfected with the plasmid pC53-SN3 or pCMV-Neo-Bam for overexpression of wild-type human p53. Twenty-four hours after transfection, cells were treated with cisplatin (3 μM) for 1 hr and then were continuously incubated with fresh media for indicated hours. Cell lysate was obtained by lysing the cells in lysate buffer 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.