Figure 5.

Caspase 9 and Fas-L activities in the four cancer cell lines after treatment with 5FU. HCT116, HepG2, MCF-7 and HeLa cells were treated with IC60 for each cell line (2.2, 7.0, 24.5 and 50 μg/ml 5FU, respectively). Control and 5FU-treated cells were collected after 48 and 72 h and cell lysates were prepared. Fas-L and caspase 9 activities in the four cell lines served as markers for the extrinsic and intrinsic pathways of apoptosis induction, respectively, and were monitored colourimetrically using the CaspASE assay system. Each point is the mean ± SEM of three separate experiments. ^aStatistical significance compared with the control group, P<0.01. Fas-L, Fas ligand; 5FU, 5-fluorouracil; IC60, 5FU concentration that results in 40% cell death compared with control cell growth.