Effect of STI 571 on the antiapoptotic effect of Steel factor (SLF) on M-07e cells
| Condition . | Early apoptosis (% of stained cells) . | Late apoptosis (% of stained cells) . |
|---|---|---|
| 10% fetal-calf serum (FCS) + GM-CSF | 4.4 | 1.8 |
| 1% bovine serum albumin (BSA) | 18.9 | 11.9 |
| SLF | 10.4 | 4.5 |
| SLF + 10 μmol/L STI 571 | 20.8 | 12.2 |
| SLF + 1 μmol/L STI 571 | 20.5 | 11.3 |
| SLF + 0.1 μmol/L STI 571 | 10.8 | 4.5 |
| Condition . | Early apoptosis (% of stained cells) . | Late apoptosis (% of stained cells) . |
|---|---|---|
| 10% fetal-calf serum (FCS) + GM-CSF | 4.4 | 1.8 |
| 1% bovine serum albumin (BSA) | 18.9 | 11.9 |
| SLF | 10.4 | 4.5 |
| SLF + 10 μmol/L STI 571 | 20.8 | 12.2 |
| SLF + 1 μmol/L STI 571 | 20.5 | 11.3 |
| SLF + 0.1 μmol/L STI 571 | 10.8 | 4.5 |
GM-CSF indicates granulocyte-macrophage colony-stimulating factor. Serum and growth factor were withheld from M-07e cells for 24 hours before the cells were treated with either complete medium (10% FCS and GM-CSF), RPMI and 1% BSA with and without SLF (200 ng/mL), or RPMI, 1% BSA, and SLF, and various doses of STI 571. Apoptosis at 48 hours was assessed by using a flow cytometric assay to measure cellular binding of a conjugate of annexin V and fluorescein isothiocyanate, conjugated (FITC), as well as uptake of the vital stain 7-amino-actinomycin D (7-AAD). A total of 10 000 cells were analyzed for each condition. Results are expressed as the percentage of cells that stained positively for annexin V-FITC only (early apoptosis) or for both annexin V-FITC and 7-AAD (late apoptosis). Representative results from 1 of 3 independent experiments are shown.