Figure 4.
Enhancement of DNA fragmentation during apoptosis by the overexpression of CAD. (A) DNA fragmentation in human cell lines during apoptosis. Five × 105 human Jurkat cells or 2 × 105 CHU-2 or HeLa cells were treated at 37°C for the indicated periods of time with 10 μM staurosporine, and the chromosomal DNA was analyzed by electrophoresis on an agarose gel. (B) Overexpression of CAD in HeLa cells transformed with the CAD expression vector. The total cell lysates were prepared from the parental HeLa cells (lane 1) and the CAD-transformed clones (lane 2) and analyzed by Western blotting using rabbit antibody against mouse CAD. (C) Enhanced DNA fragmentation in HeLa cells overexpressing CAD. Parental HeLa cells or the transformants overexpressing CAD were incubated at 37°C with 1.0 μg/ml of the agonistic anti-human Fas antibody (CH-11) in the presence of 0.05 μg/ml actinomycin D. At the indicated time, chromosomal DNA was prepared. Analysis was by electrophoresis on an agarose gel.