Fig. 1.
Comparable protein levels of wild-type p53 and transcriptionally impaired p53Q22/S23 produce apoptosis in H1299 cells treated with daunorubicin. (A) Cultures expressing inducible wild-type p53 (WT) in the presence of 0 ng/ml tet and inducible p53Q22/S23 (22/23) in the presence of 10, 5, and 0 ng/ml tet were left untreated or were treated with daunorubicin for 48 h. Cell extracts from these samples were prepared and resolved by SDS/PAGE followed by transfer to nitrocellulose membranes. Blots were probed with a mixture of p53 monoclonal PAb1801 and actin polyclonal antibodies. (B) Cell lines expressing inducible wild-type p53 in the presence of 4,500 and 0 ng/ml tet and inducible p53Q22/S23 in the presence of 4,500, 10, 5, and 0 ng/ml tet were left untreated or were treated with daunorubicin for 48 h. FACS analysis was used to obtain values for the percentage of sub-G1 cells. The bars show the percentage of sub-G1 DNA content of cells 48 h after daunorubicin treatment. White bars, untreated, without p53; black bars, untreated, with p53; light gray bars, treated, without p53; dark gray bars, treated, with p53.