Table 2. IC 50s of gemcitabine and GEM-ZZQ for different lung cancer cell lines .
| Cell lines | GEM IC
50 (μmol/L) a | GEM-ZZQ IC
50 (μmol/L) a | Fold change b | 
| Student's t-test was used to test the differences between the two groups. * P < 0.05. aData are presented as mean ± standard deviation, n = 3. bFold change = IC 50 (GEM-ZZQ)/IC 50 GEM. GEM indicates gemcitabine. GEM-ZZQ indicates the prodrug with an H 2O 2-sensitive thiazolidinone moiety at the 4th amino group of GEM. | |||
| H1975 | 0.010±0.001 | 0.014±0.004 | 1.400 | 
| HCC827 * | 1. 544±0.069 | 2.136±0.120 | 1.383 | 
| H1299 * | 0.470±0.047 | 0.567±0.014 | 1.206 | 
| H157 * | 0.451±0.055 | 1.061±0.087 | 2.353 | 
| H460 * | 0.001±0.000 | 0.004±0.000 | 3.909 |