Table 1. Drug sensitivities of parental cells and drug-resistant sublines.
| IC50±s.d.a (nmol/l) | |||||
|---|---|---|---|---|---|
| Drugs/cells | A549 | A549/A400 | CL1 | CL1/A100 | CL1/A200 |
| Pemetrexed | 1304.7±94.7 (1.0) | 49 333.3±1755.9 (37.8) | 32.1±0.2 (1.0) | 736.2±49.1 (22.9) | 2777.8±481.1 (86.5) |
| Methotrexate | 48.7±0.6 (1.0) | 113.3±4.7 (2.3) | 11.2±0.2 (1.0) | 12.0±0.5 (1.1) | 27.4±1.6 (2.5) |
| 5-FU | 6000.0±500.0 (1.0) | 7900.0±700.0 (1.3) | 3980.0±300.0 (1.0) | 3330.0±180.0 (0.8) | 2460.0±320.0 (0.6) |
| Docetaxel | 6.4±0.1 (1.0) | 6.8±0.4 (1.1) | 3.1±0.2 (1.0) | 5.6±0.8 (1.8) | 6.0±0.4 (1.9) |
| Vincristine | 14.9±0.1 (1.0) | 4.2±0.1 (0.3) | 4.2±0.3 (1.0) | 3.3±0.1 (0.8) | 2.6±0.4 (0.6) |
Note: A549/A400 is a pemetrexed-resistant A549 subline; CL1/A100 and CL1/A200 are pemetrexed-resistant CL1 sublines. Cell survival was determined by MTT assay. (Fold resistance) was relative to the parental cell line.
Pemetrexed was provided by Eli Lilly Corporation (Indianapolis, IN, USA). Docetaxel was obtained from Aventis Pharmaceuticals Inc. (Bridgewater, NJ, USA). Methotrexates (MTX), 5-fluorouracil (5-FU) and vincristine were purchased from Sigma-Aldrich (St Louis, MO, USA).
a
Data are the mean±s.d. of at least three independent experiments done in triplicate.