Figure 3. B392 is a depolymerizing agent and caused mitotic arrest.

(A) In vitro tubulin polymerization assay was performed to evaluate the effect of B392 on microtubule dynamics. In cell-free condition, tubulin proteins were in reaction buffer in the presence or absence of B392 (3 or 10 μM), paclitaxel (10 μM) or vincristine (10 μM). Assembly of microtubules was determined by measuring absorbance at 340 nm. (B) HL60 cells were exposed to 0.1 μM B392, 10 μM vincristine and 10 μM paclitaxel for 24 h. The changes of microtubule network were visualized by staining β-tubulin as arrows indicated. Nuclear DNA was stained by DAPI. 10 μM vincristine and 10 μM paclitaxel were used as positive controls for tubulin depolymerization and tubulin polymerization, respectively. (C) HL60 cells were treated 0.1 μM B392 time-dependently to detect the expressions of G2/M related proteins.