Table 1.
Cytotoxicity profile of 1A9/EpoR cells to drugs acting on MTs
| Drug | IC50,* nM
|
||
|---|---|---|---|
| 1A9 | 1A9/A8 (β274) | 1A9/B10 (β282) | |
| PTX | 2 ± 0.23 | 19.5 ± 1.14 (10) | 13 ± 0.58 (6.5) |
| Docetaxel | 1 ± 0.15 | 7 ± 0.45 (7) | 5 ± 0.25 (5) |
| Baccatin | 550 ± 70 | 3950 ± 1060 (7) | 3000 ± 870 (5.4) |
| Epo A | 3.2 ± 0.42 | 127 ± 14.7 (40) | 182 ± 6.25 (57) |
| Epo B | 0.22 ± 0.03 | 5.4 ± 0.64 (25) | 5.2 ± 0.35 (24) |
| B-pyridine | 0.1 ± 0.015 | 3 ± 0.25 (30) | 6 ± 0.2 (60) |
| Sarc. A analogue† | 3.75 ± 0.02 | 1.18 ± 0.12 (0.3)‡ | 0.45 ± 0.018 (0.12)‡ |
*
IC50 values (±SEM) represent the mean of 3–13 independent 96-h growth inhibition assays. Values in parentheses are fold-resistance factors, defined as the IC50 value obtained for the β-tubulin mutant line divided by that obtained for the parental line.
† Sarcodictyin A analogue is methylated at the C-3 oxygen atom of the parent compound. This analogue is shown as an active member representative of the sarcodictyin family.
‡ The fold resistance factors in parentheses are less than 1 because the IC50 values for the β-tubulin mutant cells are lower than the IC50 for the 1A9 parental cells.