Proliferation inhibition effect of combination treatments of ixazomib and chemotherapy agents
Next, we assessed whether the combination of ixazomib and commonly used chemotherapy agents (cisplatin and fluorouracil) exhibits additive or synergistic proliferation inhibition of ESCC cells. We applied a universal reference experimental scheme (isobologram analysis) for evaluating the effects of possible synergistic interaction(Ooko et al. , 2017). The ESCC cell lines were treated with varying concentrations of ixazomib at indicated concentrations of cisplatin and fluorouracil for 24 h. In Kyse150 and Kyse510 cells, the IC50-values of ixazomib in combination with cisplatin were reduced by less than the IC50 of ixazomib alone. However, we observed no similar synergistic effects between ixazomib and fluorouracil in ESCC cells (Figure 6A, B). This phenomenon suggests that the combination of ixazomib and cisplatin has therapeutic potential in the treatment of ESCC.