HATi II induces apoptosis, DNA fragmentation and activation of caspase-3 in glioma cell lines. (A, B) The morphologic changes in U251 (A) and SHG44 cells (B) treated with HATi II were evaluated using Hoechst 33342 staining and fluorescence microscopy. (C, D) Apoptosis was assessed by terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling (TUNEL) analysis in U251 (C) and SHG44 cells (D) treated with HATi II. Apoptotic cells (green) were detected by laser scanning confocal microscopy at an excitation of 515-565 nm, while the cell nuclei were stained with DAPI. The two images have been superimposed to show the apoptotic cells (green) and their position. (E and F) Western-blot analysis of the activation of caspase-3, caspase-9 and PARP in U251 (E) and SHG44 cells (F) treated with HATi II for 48 h.