Fig. 5.
Efficacy of docetaxel/gefitinib combination treatment is sequence-dependent. a–c Representative dose response curves of gefitinib sensitive OE21 (a), gefitinib resistant KYSE520 (b) and gefitinib sensitive TE8 (c) ESCC cells were treated for 4 days with gefitinib or docetaxel and both drugs either in combination or sequentially: 4 days both drugs (both), 48-h gefitinib treatment followed by addition of docetaxel for the remaining 48-h (G—D) or 48-h docetaxel treatment followed by addition of gefitinib for the remaining 48 h (D—G). Cells were analysed by CellTitre-Glo® assay (d) Log2 combination indices were determined from assays described in a–c using CalcuSyn software, where 0 = additive effects, < 0 = synergistic effects, > 0 = antagonistic. log2 CI values at 50%, 75% and 90% effective dose ED50, ED75 and ED90, respectively, are displayed