Loss of Leukemic (Ph+) LTC-IC Activity in 10-Day Suspension Cultures of CD34+CD38− CML Blood Cells
| CML No. . | LTC-IC (per 100 input cells) . | CFC (per 100 input cells) . | ||||
|---|---|---|---|---|---|---|
| . | Day 0 . | Day 10 . | Fold Change* . | Day 0 . | Day 10 . | Expansion* . |
| 1a | 27 | <0.002 | <0.000074 x | 3 | 196 | 65 x |
| 1b† | 45 | <0.0002 | <0.000004 x | 3 | 742 | 250 x |
| 2a | 2 | <0.002 | <0.001 x | 9 | 144 | 16 x |
| 2b | <0.001 | <0.0005 | — | 9 | 2,940 | 330 x |
| 3 | 9 | <0.001 | <0.0001 x | 11 | 990 | 90 x |
| 4 | 9 | 0.2 | 0.022 x | 12 | 126 | 10 x |
| CML No. . | LTC-IC (per 100 input cells) . | CFC (per 100 input cells) . | ||||
|---|---|---|---|---|---|---|
| . | Day 0 . | Day 10 . | Fold Change* . | Day 0 . | Day 10 . | Expansion* . |
| 1a | 27 | <0.002 | <0.000074 x | 3 | 196 | 65 x |
| 1b† | 45 | <0.0002 | <0.000004 x | 3 | 742 | 250 x |
| 2a | 2 | <0.002 | <0.001 x | 9 | 144 | 16 x |
| 2b | <0.001 | <0.0005 | — | 9 | 2,940 | 330 x |
| 3 | 9 | <0.001 | <0.0001 x | 11 | 990 | 90 x |
| 4 | 9 | 0.2 | 0.022 x | 12 | 126 | 10 x |
Highly purified CD34+CD38− cells (≥99% pure) were isolated by FACS from selected cryopreserved samples of light density (<1.077 g/mL) blood cells of 4 different CML patients because they had been previously shown to contain elevated numbers of exclusively Ph+ LTC-IC and CFC. The cells were incubated for 10 days at 37°C in a serum-free medium containing FL and SF at 100 ng/mL each, and IL-3, IL-6, and G-CSF at 20 ng/mL each. At the end of 10 days, LTC-IC and CFC assays were performed on the harvested cells.
Calculated as Day 10 value ÷ Day 0 value.
b experiments were set up with a separate thawed aliquot of cells from the same patient sample used for the “a” experiments and represent the control cultures (CML cells only) set up in parallel with the mixing experiments reported in Table 6.