Figure 4.

Activity of (A) caspase-3, (B) caspase-9 and (C) caspase-8 measured in PBS-treated and 50 µg/ml RC-RNase-treated DBTRG cells at the indicated time points (24 and 72 h). The activity of caspase-3 and caspase-9 was increased in RC-RNase-treated cells compared with PBS-treated cells. The data was obtained from three independent experiments and expressed as the mean ± standard deviation. The data suggested that casase-3 and caspase-9 were significantly activated in RC-RNase-treated cells at 72 h. PBS, phosphate-buffered saline; RC-RNase, Rana catesbeiana ribonuclease.