Figure 2.

Effect of AspA on cell cycle progression and tubulin polymerization in RKO cells. (A,B) Cells were treated with the indicated concentrations of AspA for 48 h (A) or 5 μM of AspA for indicated times (B) and then analyzed by flow cytometry. (C,D) The levels of G₂/M regulatory proteins in cells were determined after treatment with various concentrations of AspA for 48 h (C) or 5 μM of AspA over time (D) by western blot analysis. β-Actin was used as a loading control. (E) Inhibitory effect of AspA on tubulin polymerization. The tubulin assembly in the presence of vehicle or indicated compounds was analyzed by measuring the fluorescence emitted at 450 nm using 360 nm as an excitation wavelength for 60 min at 37 °C. Paclitaxel (TXL) and vinblastine (VBL) were used as reference compounds. The data are presented as means ± SD.