TABLE 1.
Sensitivity to HER2‐targeted therapies and standard‐care chemotherapeutics
| MDA‐MB‐361 S | MDA‐MB‐361 TR | MDA‐MB‐361 TCR | |||||
|---|---|---|---|---|---|---|---|
| Drug target | Drug name | IC50 (nmol/L) | IC50 (nmol/L) | Relative resistance | IC50 (nmol/L) | Relative resistance | |
| HER2 | T‐DM1 | 0.23 | 1.95 | 7.9(***) | 1.35 | 5.3(*) | |
| Trastuzumab(#) | 0.11 | 0.16 | 1.4 | 0.21 | 1.9 | ||
| Pertuzumab | 9.8 | 18.7 | 1.9 | 12.31 | 1.3 | ||
| Lapatinib | 4817 | 4428 | 0.9 | 3227 | 0.7 | ||
| Afatinib | 23.2 | 43.7 | 2.4(*) | 13.1 | 0.6 | ||
| Topoisomerase I | Irinotecan | 3443 | 5203 | 1.5 | 3797 | 1.1 | |
| PNU‐159682 | 0.10 | 0.16 | 1.0 | 0.1 | 0.8 | ||
| DNA | Antimetabolite | Fluorouracil | 16 227 | 9020 | 0.6 | 15 323 | 0.9 |
| Alkylating | Cisplatin | 3867 | 7023 | 1.8 | 9457 | 2.4 | |
| Intercalating | Doxorubicin | 6.57 | 7.31 | 1.1 | 8.81 | 1.3 | |
| Tubulin | Polymerizing | Paclitaxel | 0.08 | 0.17 | 2.0 | 0.23 | 2.7 |
| Depolymerizing | Vincristine | 0.12 | 0.40 | 3.2 | 0.67 | 5.3(*) | |
| Vinorelbine | 2.26 | 3.99 | 2.8(*) | 4.61 | 4.8 | ||
| Colchicine | 1.98 | 3.84 | 1.8(*) | 2.27 | 1.5 | ||
| S‐methylDM1 | 0.07 | 0.16 | 2.3 | 0.13 | 1.8 | ||
| DM1 | 1.68 | 4.40 | 2.9(*) | 3.52 | 4.7 | ||
The sensitivity after a 6 day exposure to the indicated anti‐cancer agents was studied by MTT cytotoxic assays. Data shown as the IC50 values of a single experiment, representative of 3‐4 independent experiments, and the relative resistance is the mean ratio of the IC50 of each resistant cell line over the parental cell line from 3‐4 independent experiments (#: IC75). Statistics were calculated using the Student t test (*:P < .05; **P < .01; ***P < .001).
Bold values indicate relative resistance numbers