Fig. 2

Adriamycin apoptosis as assessed by analysis of DNA fragmentation on a simple agarose gel. MCF-7 (p53 wild-type) and MDA-MB 231 (p53 mutant) cells were maintained in DMEM/F-12 media supplemented with 5% DCC-CS and exposed to 100 nM of adriamycin for 48 hr. DNA was then extracted and analyzed as described in Materials and Methods. The presence of ∼180 bp DNA ladders (DNA fragmentation) marks apoptotic death in vitro. Notably, only MDA-MB 231 cells extracts presented with evidence of DNA fragmentation. The adriamycin apoptosis in MDA-MB 231 cells was apparently p53-independent. Obviously, MCF-7 cells were resistant to adriamycin (100 nM) apoptosis in vitro.