IC25, IC50, and IC75 values of 5-fluorouracil (5-FU) and methotrexate (MTX) in HCT116 colon cancer cells expressing sense (FPGS-S), endogenous (vector alone (VA)), and antisense (FPGS-AS) folylpolyglutamate synthetase (FPGS)
| 25% survival | 50% survival | 75% survival | ||||
|---|---|---|---|---|---|---|
| IC25 | 95% CI | IC50 | 95% CI | IC75 | 95% CI | |
| IC25, IC50, and IC75 values (that is, drug concentration that corresponded to a reduction in cell survival by 75%, 50%, and 25%, respectively, compared with the survival of untreated control cells) were calculated from plots of drug concentration versus proportion of cells that survived. | ||||||
| 5-FU (μM) | ||||||
| FPGS-S | 3.90 | (3.30, 4.63) | 1.64 | (1.26, 2.14) | 0.35 | (0.26, 0.47) |
| VA | 17.03 | (15.39, 18.83) | 3.03 | (2.71, 3.37) | 0.54 | (0.42, 0.68) |
| FPGS-AS | 59.83 | (48.83, 73.30) | 4.57 | (4.15, 5.02) | 0.69 | (0.47, 1.01) |
| MTX (nM) | ||||||
| FPGS-S | 13.93 | (10.99, 17.67) | 9.54 | (8.18, 11.13) | 6.54 | (6.05, 7.07) |
| VA | 13.18 | (12.38, 14.04) | 8.82 | (8.49, 9.16) | 5.89 | (5.79, 6.00) |
| FPGS-AS | 10.95 | (10.32, 11.61) | 7.53 | (7.29, 7.79) | 5.18 | (5.10, 5.27) |