By contrast, vincristine induces mitotic arrest by 1201438-56-3 destabilizing microtubules. 9nM bortezomib and 4nM vincristine 1381289-58-2 combination induces a decrease in total levels and phosphorylated Bcr-Abl, as well as an increase in caspase 3 cleavage, the effects being higher than in singular treatments. Moreover, the combinations of bortezomib with docetaxel or vincristine resulted in a significant and higher increase in cell death compared with individual treatments. Collectively, our findings indicate that the bortezomib in combination with four different mitotic inhibitors, that repress mitosis by different mechanisms are able to shut down Bcr-Abl activity and result in caspase-dependent cell death in TKIs-resistant and -sensitive Bcr-Abl-positive cell lines. To check whether the difference was originated from different reaction buffer, absorbance assay was also carried out in a buffer used in redox fluorescence assay. Although CDC showed strong redox potential in fluorescence assay, the absorbance change was still increasing pattern even in the same buffer condition. The absorbance pattern after substrate depletion was observed by measuring absorbance change after long incubation with redox inhibitor, zileuton. After long incubation, the absorbance was gradually increased just like non-redox control. The accuracy and efficacy of the fluorescence assay were also determined by testing the selected compounds and measuring the amount of remaining 13-HpODE by DCF fluorescence. The fluorescence values of the reaction mixtures ranged from 300 to 6000. The maximum amount of peroxide yielded the highest signal, and the strong redox inhibitor reduced it to 300. The highest and lowest compound concentrations in the serially diluted set were respectively. This range covered the EC50 level for all of the tested compounds. The final DMSO amount in the reaction mixture was kept at 1% throughout the experiments. Zileuton was used in each experiment as the positive control. Four wells without any inhibitors represented the ����100% peroxide���� control wells, and the average fluorescence values in the control wells were used for normalization of fluorescence data. The concentration points were duplicated in each test and the concentration-depend
