Effect of induction of exogenous p18 and p27 on growth and cell cycle profiles of MEL cell transfectants
| Clone . | Dox . | T(g), h . | Phase G0-G1, % . | Phase S, % . | Phase G2-M, % . |
|---|---|---|---|---|---|
| p18.5 | − | 12.2 | 31.6 | 61.4 | 6.9 |
| + | 12.1 | 32.3 | 58.7 | 9.0 | |
| p18.36 | − | 12.2 | 29.6 | 58.4 | 12.0 |
| + | 11.8 | 30.3 | 57.9 | 11.8 | |
| p27.16 | − | 12.1 | 28.3 | 52.0 | 19.7 |
| + | 42.1 | 84.9 | 8.0 | 7.0 | |
| p27.77 | − | 11.9 | 27.6 | 55.4 | 17.0 |
| + | 40.2 | 87.8 | 6.7 | 5.5 | |
| MEL rtTA; B1 | − | 11.9 | 28.8 | 53.4 | 17.6 |
| + | 11.8 | 29.3 | 50.4 | 19.6 | |
| Clone . | Dox . | T(g), h . | Phase G0-G1, % . | Phase S, % . | Phase G2-M, % . |
|---|---|---|---|---|---|
| p18.5 | − | 12.2 | 31.6 | 61.4 | 6.9 |
| + | 12.1 | 32.3 | 58.7 | 9.0 | |
| p18.36 | − | 12.2 | 29.6 | 58.4 | 12.0 |
| + | 11.8 | 30.3 | 57.9 | 11.8 | |
| p27.16 | − | 12.1 | 28.3 | 52.0 | 19.7 |
| + | 42.1 | 84.9 | 8.0 | 7.0 | |
| p27.77 | − | 11.9 | 27.6 | 55.4 | 17.0 |
| + | 40.2 | 87.8 | 6.7 | 5.5 | |
| MEL rtTA; B1 | − | 11.9 | 28.8 | 53.4 | 17.6 |
| + | 11.8 | 29.3 | 50.4 | 19.6 | |
The indicated MEL cell transfectant clones and parental MEL cells (clone B1) containing only the rtTA regulator were cultured in the absence (−) or presence (+) of 1 μg/mL Dox for 14 days. The cells were subcultured to 2 × 105 cells per mL each day by centrifugation and resuspension of the appropriate fraction of cells in fresh medium. The cell densities were measured daily with a Coulter counter, and the average generation time, T(g), of each culture was calculated. After 36 hours of culture, approximately 1 × 106 cells were removed from each culture, centrifuged, and suspended in 1 mL propidium iodide/sodium citrate buffer. The percentage of cells in each stage of the cell cycle was then determined by fluorescence-activated cell sorter (FACS) analysis.