Table 4. Antiproliferative Effects: IC50 Values at ER-Positive MCF-7, Tamoxifen-Resistant MCF-7TamR, and ER-Negative MDA-MB-231 Breast Cancer Cells.
| compound | MCF-7 | IC50 [nM]a | MDA-MB-231 | |
|---|---|---|---|---|
| MCF-7TamR | ||||
| thioxo-quinazolinone | 15 | 1.9 | 2 296 | >1 μM |
| 16 | 4.2 | 476.6 | n.a. | |
| 17 | 27.8 | 550.8 | n.a. | |
| 18 | 12.6 | 1 208 | n.a. | |
| 5-methoxybenzimidazole | 31 | 2.8 | n.d. | n.a. |
| 32 | 2.4 | n.d. | n.a. | |
| 34 | 4.1 | 486.3 | n.a. | |
| 36 | 1.8 | 68.7 | n.a. | |
| 38 | 0.5 | n.d. | n.a. | |
| 5-hydroxybenzimidazole | 39 | 10.6 | 531.0 | n.a. |
| 40 | 4.5 | 543.7 | n.a. | |
| 41 | 9.8 | 1 711 | n.a. | |
| 42 | 11.5 | 235.7 | n.a. | |
| 43 | 5.6 | 325.1 | >1 μM | |
| references | GW7604 | 52.0 | 956.9 | n.a. |
| fulvestrant | 0.58 | 1.8 | n.d | |
| 4-OHT | n.d | n.d | n.d |
a
Values represent means of ≥3 independent experiments; n.d., not determined; n.a., not active.