Fig. 4.

Effects of HDAC inhibitors on cellular proliferation and colony formation. Logarithmically growing established human glioma cell lines were incubated with varying concentrations of SAHA (A), trichostatin A (B), or sodium butyrate (C) for 3 days. The relationship between vandetanib concentration and cell numbers was assessed semiquantitatively by spectrophotometric measurement of MTS bioreduction in six established malignant human glioma cell lines. Points represent the mean of four measurements ± S.D. There was a dose-dependent reduction in cell growth. Control cells were treated with equivalent concentrations of vehicle (DMSO). D, graph showing the relationship between colony counts (± S.D.) and SAHA concentration. Human glioma cell lines U87, A172, LNZ308, and T98G were exposed to the indicated concentrations of SAHA for 24 h. On the next day, the medium was changed, complete median was added, and cells were grown for an additional 14 days in the absence of inhibitors. Control cells (0) were treated with equivalent concentrations of vehicle (DMSO). Colonies were then counted. Points represent the mean of two experiments ± S.D.