IC50 values of BCNU and CPTs tested on CHO-derived cells
Drug | Cell | IC50a | Resistance Indexb |
|---|---|---|---|
| BCNU (μM) | CHO | 14.5 ± 3.5 | 1.00 |
| Vec | 16.5 ± 2.1 | 1.13 | |
| S12− | 19.0 ± 2.8 | 1.39 | |
| S12+ | 46.5 ± 3.5*c | 3.08 | |
| CPT (nM) | CHO | 40.5 ± 3.5 | 1.00 |
| Vec | 38.5 ± 4.2 | 0.94 | |
| S12− | 42.5 ± 2.1 | 1.07 | |
| S12+ | 57.5 ± 3.5* | 1.40 | |
| SN38 (nM) | CHO | 31.0 ± 2.8 | 1.00 |
| Vec | 32.5 ± 2.1 | 1.07 | |
| S12− | 33.0 ± 2.8 | 1.05 | |
| S12+ | 40.5 ± 2.6* | 1.25 | |
| TPT (nM) | CHO | 90.0 ± 4.2 | 1.00 |
| Vec | 91.5 ± 3.5 | 1.03 | |
| S12− | 93.0 ± 4.2 | 1.0 | |
|
| S12+ | 126.0 ± 2.8* | 1.37 |
↵* Statistically significant.
↵ a Cells were treated with various concentrations of test drugs for 3 days. Cell growth was determined by methylene blue dye assay. The IC50 value resulting from 50% inhibition of cell growth was calculated. Each value represents the mean ± S.D. of three independent experiments.
↵ b Resistance index (× fold) means the relative resistance of transfectants at IC50 compared with parental CHO cells.
↵ c A p value < 0.05.