Table 1. Effects of gemcitabine, topotecan or their combinations on cell proliferation, caspase activity and apoptosis in A549 and Calu-6 cells. Data are the mean±s.e. from three independent experiments.
Treatment | Cells | IC50 (ng ml−1)a | Apoptotic indexb | Caspase activity (pmol min−1 mg−1)c |
---|---|---|---|---|
Control | A549 | / | 4.3±0.6% | 0.12±0.08 |
Calu-6 | / | 3.1±0.3% | 0.10±0.06 | |
Topotecan | A549 | 840.2±121.2 | 7.7±1.4% | 0.32±0.11 |
Calu-6 | 562.3±93.5 | 6.1±0.4% | 0.39±0.13 | |
Gemcitabine | A549 | 131.2±30.3 | 13.4±4.6% | 0.86±0.14 |
Calu-6 | 1662.4±360.6 | 8.6±2.0 | 0.69±0.25 | |
Gemcitabine → topotecan | A549 | 620.1±104.1 | 10.5±0.7% | 1.07±0.12 |
Calu-6 | 2063.8±414.6 | 11.5±2.8% | 0.94±0.31 | |
Gemcitabine+topotecan | A549 | 12.4±1.4 | 34.0±3.6% | 2.76±0.10 |
Calu-6 | 40.4±4.76 | 27.6±3.6% | 2.55±0.37 | |
Topotecan → gemcitabine | A549 | 6.3±0.3 | 29.2±5.9% | 1.43±0.11 |
Calu-6 | 179.5±38.7 | 19.8±3.2% | 1.55±0.28 |
50% inhibitory concentrations of cell growth.
Percentage ratio between the number of cells displaying apoptotic appearance and the total number of counted cells.
Enzyme activity is normalised with respect to total protein content of each cell extract.