Growth inhibition by antifolate drugs toward hPCFT- and hRFC-stable R2 CHO transfectants
Growth inhibition was measured by a fluorescence (Cell Titer Blue)-based assay after 96 h of exposure to a range of inhibitor concentrations. Results are presented as 50% inhibitory concentrations (IC50) ± S.E. from more than three experiments. Mtx, GW1843U89, Lmx, Pmx, PT523, and Rtx results in the R2/hPCFT4, R2/VC, PC43-10, and R2 cells were reported previously (Deng et al., 2009).
| Antifolate | R2/hPCFT4 | R2/VC | PC43-10 | R2 | R1-11-RFC6 | R1-11-PCFT4 |
|---|---|---|---|---|---|---|
| nM | ||||||
| Mtx | 120.5 ± 16.8 | >1000 | 12 ± 1.1 | 216 ± 9 | 35.7 ± 7.1 | 218.2 (15.1) |
| GW1843U89 | >1000 | >1000 | 11 ± 3.3 | >1000 | N.D. | N.D. |
| Lmx | 38.6 ± 5.0 | >1000 | 12 ± 2.3 | >1000 | 36.1 ± 9.9 | 278.3 ± 26.2 |
| Pmx | 13.2 ± 2.4 | 974.0 ± 18.1 | 138 ± 13 | 894 ± 93 | 81.7 ± 5.5 | 59.3 ± 7.4 |
| PT523 | >1000 | >1000 | 1.53 ± 0.16 | >1000 | 3.19 ± 0.4 | >1000 |
| Rtx | 99.5 ± 11.4 | >1000 | 6.3 ± 1.3 | >1000 | N.D. | N.D. |
| 1 | >1000 | >1000 | >1000 | >1000 | N.D. | N.D. |
| 1a | >1000 | >1000 | >1000 | >1000 | N.D. | N.D. |
| 2 | 23.0 ± 3.3 | >1000 | 648.6 ± 38.1 | >1000 | >1000 | 155.0 ± 12.9 |
| 3 | 212.9 ± 28.0 | >1000 | >1000 | >1000 | N.D. | N.D. |
| 4 | >1000 | >1000 | >1000 | >1000 | N.D. | N.D. |
| 5 | >1000 | >1000 | >1000 | >1000 | N.D. | N.D. |
N.D., not determined.