Fig. 3.
p53 regulators activate p53 by an HDM2-dependent mechanism. (A) A reporter plasmid containing the HDM2 promoter sequence was transfected into HCT116 p53-/- cells along with Hey1, Hes1, TFAP4, or Osr1 and β-gal plasmid. After incubating for 48 h, cells were lysed, and luciferase activity was detected and normalized based on β-gal activity. (B) Cell lysates from HCT116 p53-/- cells transfected with Hey1, Hes1, TFAP4,or Osr1 and immunoblotted with anti-HDM2 antibody. (C) mRNAs from HCT116 p53-/- cells transfected with Hey1, Hes1, TFAP4, or Osr1 were extracted, and RT-PCR was performed by using primers corresponding to HDM2 sequence.