OGAT activity, MMR efficiency, and sensitivity to TMZ, BCNU, or CDDP of human melanoma cell lines
| Cell Line1-a | OGAT1-b | % MMR1-c | IC501-d | ||||
|---|---|---|---|---|---|---|---|
| TMZ | TMZ + LTE/BG1-e | BCNU | BCNU + LTE/BG1-e | CDDP | |||
| μM | |||||||
| CR-Mel | N.D. | 35–39 | 92 ± 16 | 103 ± 13 | 38 ± 5.4 | 40 ± 7.4 | 4.0 ± 0.6 |
| LCP-Mel-Clone E4 | N.D. | 44–46 | 103 ± 14 | 103 ± 8.0 | 13 ± 1.1 | 12 ± 1.2 | 8.5 ± 0.3 |
| PR-Mel | 12 ± 6 | 3–11 | >1000 | >1000 | 17 ± 1.5 | 17 ± 0.6 | 7.0 ± 0.9 |
| GL-Mel | 52 ± 6 | 77–88 | 148 ± 17 | 36 ± 6.51-160 | 47 ± 2.5 | 37 ± 3.41-150 | 8.7 ± 0.9 |
| M14 | 107 ± 21 | 87–93 | 101 ± 11 | 23 ± 3.61-160 | 82 ± 10 | 55 ± 6.01-150 | 11 ± 1.2 |
| LCP-Mel | 184 ± 33 | 37–40 | 218 ± 20 | 143 ± 321-150 | 13 ± 1.0 | 8.2 ± 0.51-160 | 5.6 ± 0.3 |
| LCP-Mel-Clone E3 | 331 ± 46 | 45–47 | 368 ± 36 | 145 ± 351-160 | 45 ± 4.4 | 9.2 ± 1.31-160 | 8.3 ± 1.2 |
| M10 | 533 ± 45 | 89–92 | 301 ± 28 | 24 ± 4.01-160 | 57 ± 5.5 | 22 ± 2.41-160 | 3.3 ± 0.3 |
| PD-Mel | 631 ± 64 | 2–9 | 448 ± 32 | 436 ± 43 | 47 ± 3.5 | 22 ± 1.41-160 | 19 ± 2.5 |
| SK-Mel-28 | 660 ± 22 | 43–49 | 688 ± 47 | 331 ± 131-160 | 70 ± 2.5 | 34 ± 0.31-160 | 11 ± 0.9 |
| CN-Mel | 827 ± 72 | 90–94 | 778 ± 32 | 369 ± 131-160 | 74 ± 2.9 | 35 ± 2.11-160 | 20 ± 4.5 |
N.D., not detectable.
↵1-a Cells were incubated with graded concentrations of the indicated drugs for 5 days and then analyzed for cell growth by the MTT assay.
↵1-b OGAT activity is expressed in terms of fmoles of 3H-methyl groups transferred per milligram of protein in cell extract. Each value represents the mean ± standard error of the mean of at least three independent experiments.
↵1-c Efficiency of MMR displayed by the cell line in two independent experiments.
↵1-d Drug concentration required to inhibit cell growth by 50%. Each value represents the mean ± standard error of the mean of at least three independent experiments.
↵1-e LTE/BG was performed by incubating cells with 5 μM BG for 2 h before treatment with TMZ or BCNU and maintaining the inhibitor in culture up to the end of the assay.
↵1-160 P < 0.01,
↵1-150 P< 0.05 according to Student's t test comparing for each cell line the IC50 values obtained in the presence of BG with those obtained without the inhibitor.