Fig. 7. Role of p53 in mTERT-mediated resistance to cell death. (A) p53 protein levels of untreated or cells treated with 5 µM cisplatin, 0.3 µg ml^–1 doxorubicin and 0.5 mM H₂O₂ were determined by western blotting. Actin levels were determined to show loading. (B) Expression of p53 target genes (bax, noxa and puma) in vector-transfected and mTERT-expressing ES cells was determined by RT-PCR. Total RNA was extracted from untreated cells and ES cells treated with 5 µM cisplatin or 0.3 µg ml^–1 doxorubicin and reverse transcribed into cDNA for PCR of p53 target genes. (C) Activation of caspase-3 was determined after doxorubicin treatment (0.3 µg ml^–1) of pcDNA-transfected and mTERT-overexpressing cells by staining with FITC-conjugated cleaved caspase-3-specific antibody and flow cytometry.