Fig. 2.

a D54, U373 and U87 cells were treated with vorinostat (3 µM) for 24 and 48 h and analyzed for apoptotic cells by flowcytometric measurement of the sub G1 cell cycle fraction. b Cells were synchronized in the G1 phase cell cycle boundary by a thymidine/urea double block, treated with vorinostat (3 µM) and released. Cells in each condition were harvested at the periods indicated and analyzed by flowcytometry. Data shown are representative of two independent experiments. c Normal huMan astrocytes (NHA) treated with vorinostat (3 µM) or vehicle (DMSO) were assessed for changes in p21 levels, acetylation of histones and total histone levels after 48 h of exposure to the agent. d NHA, cultured in astrocyte basal medium, were treated with vorinostat (3 µM); flowcytometric analysis was performed to detect cell cycle changes and the sub-G1 fraction at the times indicated. e D54 cells were cultured on coverslips and exposed to vorinostat (3 µM) for the periods indicated; the cells were fixed and immunostained with DAPI (to label nuclei) and phospho histone H3 (for mitotic cells). Mitotic and total cells were counted after appropriate immunostaining. Data shown in graph are the mean counts of positive cells derived from two independent measurements