Fig. 5

HDAC6 was involved in vincristine/SAHA-induced cell death. a MOLT-4 cells were treated with the indicated drugs for 12 and 24 h. The cell lysates were used to determine the HADC6 protein level and activity. b Cells were treated with tubastatin A alone, which is a specific HDAC6 inhibitor, or combined with 1 and 3 nM vincristine for 48 h. The cell viability was evaluated by MTT assay. c Cells incubated with tubastatin A alone or in combination with the indicated concentration of vincristine for 24 and 48 h. The cell cycle distribution was measured by flow cytometry. The figures are shown as quantitative data in the time course. d The CI value of combining tubastatin A with vincristine on G₂/M and sub-G₁ phases. e Cells were treated with 10 or 20 μM tubastatin A (Tuba) alone and combined with 1 or 3 nM vincristine. The cell lysates were used for western bolt analysis. f CCRF-CEM cells were co-treated with vincristine and ACY1215, an HDAC6-specific inhibitor, for 48 h. The CI value of combining treatment on the sub-G₁ phase