plus
| Anti-HER2 | Anti-HER1 |
|---|
| | trastuzumab | lapatinib | gefitinib | erlotinib | cetuximab |
|---|
G28UCM | synergism 0.5 ± 0.2** | synergism 0.8 ± 0.1** | synergism 0.8 ± 0.2* | synergism 0.7 ± 0.1** | antagonism 1.9 ± 0.2** |
EGCG | additivism 1.1 ± 0.5 | antagonism 1.9 ± 0.7* | antagonism 1.8 ± 0.7* | antagonism 1.4 ± 0.2* | antagonism 2.2 ± 0.2** |
- The interaction index (Ix) for the two-drug effect in AU565 cells was calculated using isobologram analysis. The Ix parameter indicate whether the doses of the two drugs required to produce a given degree of cytotoxicity are greater than (Ix > 1 or antagonism) equal to (Ix = 1 or additivism) or less than (Ix < 1 or synergism) the doses that would be required if the effect of two agents were strictly additive. Ix values for the two drug treatment were obtained from triplicate studies. * (P < 0.05) and ** (P < 0.005) indicate the level of statistical significance of the Ix compared with an Ix of 1.0.
