Fig. 6

Synergism between Zt/g4-DM1 and chemotherapeutics. a the synergistic effect of Zt/g4-DM1 and gemcitabine in vitro. BC and NSCLC cell lines (8000 cell per well in a 96-well plate in triplicate) were cultured in DMEM with 10 % FBS and treated for 96 h with different amounts of gemcitabine, Zt/g4-DM1, or their combinations at 1:1 molar ratio. Cell viability was measured using the MTT assay. b Analysis of the synergism by Chou-Talalay plot. Percentages of cell viability from individual samples as described in A were calculated, converted, and then used for the fraction of inhibition-combination index (CI) plot as previously described [43]. Data shown here are from one of three experiments with similar results. c Effect of Zt/g4-DM1 in combination with gemcitabine in vivo. Athymic nude mice (five mice per group) were subcutaneously inoculated with 5 × 10⁶ H358 or T-47D cells to allow tumor growth to reach an average volume at ~100 mm³. Zt/g4-DM1 at 10 mg/kg in a Q8 × 3 regimen was injected through tail vein. Mice injected with CmIgG-DM1 were used as the control. Gemcitabine was injected into the intraperitoneal cavity at 60 mg/kg in a Q4 × 4 schedule. Both drugs were used for the combination group according to their own dose and schedule. Tumor volume was measured every 4 days. The percentages of tumor growth inhibition were calculated from the average tumor volume as described in Fig. 5a. d Tumor inhibition by measuring tumor weight. Individual tumors from different groups were collected and weighed to obtain the average tumor weight (gram). The percentages of reduction in average tumor weight were calculated as described in Fig. 5b